CN1736604A - A kind of eggshell metal catalyst and its preparation method and application - Google Patents

Abstract

The invention discloses an egg- shell metallic catalyst and the method for preparation and the application. The catalyst is an egg- shell supported metallic catalyst with a carrier of hollow silica dioxide, which is a hollow material of certain wall and bore diameter, and comprises a noble metal of 0.1%- 5.0% and/ or a transient metal of 5.0%- 40.0%, a non- noble metallic catalyst promoter of 0- 0.5% and a hollow silica dioxide carrier of 60.0%- 99.0%, with the weight ratio of catalyst as a datum level. The egg- shell metallic catalyst can prepare with immersion method or in- situ supporting method. The catalyst has good metal dispersibility, and the metal particle diameter is minor, dispersing on the external surface, inner surface and in the pore passage. And the egg- shell metallic catalyst can catalyze CO and CO2 to prepare lower carbon number hydrocarbons and alcohol, and it also can catalyze olefin and alkyne selectively.

Description

Translated fromChinese

一种蛋壳型金属催化剂及其制备方法和应用A kind of eggshell metal catalyst and its preparation method and application

技术领域technical field

本发明涉及一种蛋壳型金属催化剂，特别涉及一种以二氧化硅为载体的蛋壳型金属催化剂及其制备方法和在催化加氢反应中的应用。The invention relates to an eggshell metal catalyst, in particular to an eggshell metal catalyst with silicon dioxide as a carrier, a preparation method thereof and an application in catalytic hydrogenation reaction.

背景技术Background technique

石油化工中选择性催化加氢反应中广泛使用负载型贵金属催化剂，如二烯烃或炔烃等选择性催化加氢制备单烯烃等。这类反应具有反应速度快、副反应多的特点，目的产物往往是中间产物，深度氢化是不期望的。理论和实践充分说明，对这大类催化反应过程，在总量不变的情况下，贵金属活性组分在粒内非均匀分布(如蛋壳型、蛋黄型)的催化剂与活性组分均匀分布的催化剂相比，可以显著提高催化剂颗粒的表观活性、选择性及抗中毒性。当催化剂存在内扩散时，蛋壳型分布的催化剂具有最高的催化活性；具有平行副反应的体系，当主反应的级数大于副反应的级数时，活性组分分布于靠近颗粒外表面，可以提高主反应的选择性等。然而，工业上常用的(固体)催化剂，其活性组分大多是均匀地分布在多孔载体的内表面。显然，这种活性组分均匀分布的催化剂，不但反应效果不良，而且大量浪费了贵金属资源。因此，具有合适活性组分分布的蛋壳型催化剂成为这类反应的理想选择，开发这种异形催化剂具有重大的应用前景。Supported noble metal catalysts are widely used in selective catalytic hydrogenation reactions in petrochemical industry, such as selective catalytic hydrogenation of diolefins or alkynes to prepare monoolefins, etc. This type of reaction has the characteristics of fast reaction speed and many side reactions. The target product is often an intermediate product, and deep hydrogenation is not expected. Theory and practice have fully demonstrated that for this type of catalytic reaction process, when the total amount remains unchanged, the catalyst and the active component of the catalyst with a non-uniform distribution of the noble metal active component (such as eggshell type, egg yolk type) and the active component are evenly distributed. Compared with the existing catalysts, the apparent activity, selectivity and poisoning resistance of the catalyst particles can be significantly improved. When the catalyst has internal diffusion, the catalyst with eggshell distribution has the highest catalytic activity; in the system with parallel side reactions, when the number of main reactions is greater than the number of side reactions, the active components are distributed near the outer surface of the particles, which can Improve the selectivity of the main reaction, etc. However, most of the (solid) catalysts commonly used in industry have their active components evenly distributed on the inner surface of the porous carrier. Apparently, such a catalyst with evenly distributed active components not only has a poor reaction effect, but also wastes a lot of precious metal resources. Therefore, eggshell-shaped catalysts with a suitable distribution of active components become an ideal choice for this type of reaction, and the development of such heteromorphic catalysts has great application prospects.

CO和CO₂催化加氢反应可将无机原料转化为应用广泛和实际应用价值更高的低碳烃或醇等，不仅充分利用了自然环境中丰富的CO₂和煤炭资源，也可以减少环境中的CO₂，从而减轻温室效应的影响。我国有丰富的煤炭资源，通过水煤气变换可以将煤炭转化为合成气(CO+H₂)，从而通过催化剂的催化作用转变为应用价值更高和前景更广的烃类或醇类。对于催化加氢来说，贵金属催化剂的作用就是通过贵金属颗粒对H₂、CO的吸附作用，并在其上进行反应，并可通过加入合适的助催化剂来提高催化剂的活性和选择性。由于铂(Pt)、钯(Pd)、铑(Rh)等贵金属的价格昂贵、资源匮乏，通常应采取适当的制备方法和工艺条件来减少贵金属的颗粒尺寸，增大贵金属在载体上的分散度，提高催化剂的活性和利用率。此外，VIII族的过渡金属，如铜(Cu)、锌(Zn)、镍(Ni)是一种高效催化剂，特别是在催化加氢反应中的活性较高，制备负载型的镍催化剂可以使催化活性中心分散，提高催化活性。可以负载金属催化剂的载体一般选择SiO₂、γ-Al₂O₃、分子筛、沸石等，助催化剂一般选择碱金属、碱土金属或者VIB和VIIIB族的非贵金属。The catalytic hydrogenation reaction of CO and_CO2 can convert inorganic raw materials into low-carbon hydrocarbons or alcohols with a wide range of applications and higher practical application value, which not only makes full use of the abundant_CO2 and coal resources in the natural environment, but also reduces environmental pollution. CO₂ , thereby mitigating the impact of the greenhouse effect. China has abundant coal resources. Coal can be converted into synthesis gas (CO+H₂ ) through water-gas shift, and then transformed into hydrocarbons or alcohols with higher application value and wider prospects through the catalytic action of catalysts. For catalytic hydrogenation, the role of noble metal catalysts is to adsorb H₂ and CO through noble metal particles and react on them, and the activity and selectivity of the catalyst can be improved by adding suitable co-catalysts. Because platinum (Pt), palladium (Pd), rhodium (Rh) and other noble metals are expensive and scarce in resources, appropriate preparation methods and process conditions should be adopted to reduce the particle size of the noble metal and increase the dispersion of the noble metal on the carrier. , improve catalyst activity and utilization. In addition, transition metals of group VIII, such as copper (Cu), zinc (Zn), nickel (Ni) are a kind of high-efficiency catalysts, especially in catalytic hydrogenation reactions, the activity is higher, and the preparation of supported nickel catalysts can make The catalytic active center is dispersed to improve the catalytic activity. Carriers that can support metal catalysts are generally selected from SiO₂ , γ-Al₂ O₃ , molecular sieves, zeolites, etc., and co-catalysts are generally selected from alkali metals, alkaline earth metals or non-noble metals of VIB and VIIIB groups.

近些年来，国内外许多研究人员已尝试多种方法和载体制备负载型金属催化剂。Tanaka等(Tanaka S.Applied Catalysis A：General，2002，229：165-174.)以溶胶-凝胶法在硅胶上沉积负载贵金属钯。采用这种方法，能将Pd很好地分散在硅胶中，且粒度较小，此种方法制备的Pd/SiO₂催化剂较传统的浸渍法制备的催化剂金属颗粒不易团聚，所以即使是经过长时间高温处理仍然呈分散状态。但是，采用此种方法制备的催化剂，金属活性中心是均匀分布在催化剂载体上的，对快速反应不能起到控制作用。In recent years, many researchers at home and abroad have tried various methods and supports to prepare supported metal catalysts. Tanaka et al. (Tanaka S. Applied Catalysis A: General, 2002, 229: 165-174.) deposited noble metal palladium on silica gel by sol-gel method. Using this method, Pd can be well dispersed in silica gel, and the particle size is small. The Pd/_SiO2 catalyst prepared by this method is less likely to agglomerate than the catalyst metal particles prepared by the traditional impregnation method, so even after a long time High temperature treatment is still in a dispersed state. However, in the catalyst prepared by this method, the metal active centers are evenly distributed on the catalyst carrier, which cannot control the rapid reaction.

Venezia等(Venezia A M.Jouranl of Catalysis，1999，182：449-455.)介绍了以浮石为载体制备二元贵金属Ag-Pd催化剂，以及过渡金属Cu和贵金属Pd的复合催化剂。采用浸渍法制备的二元复合催化剂，由于负载的先后顺序不同，催化剂表征就体现出不同的结果。这种催化剂是以浮石为载体，与本发明采用的催化剂载体不同，但它仍然不能得到活性组分是蛋壳型分布的催化剂。Venezia et al. (Venezia A M.Jouranl of Catalysis, 1999,182:449-455.) introduced the preparation of binary noble metal Ag-Pd catalysts and transition metal Cu and noble metal Pd composite catalysts using pumice as a carrier. The binary composite catalysts prepared by impregnation method show different results due to the different loading sequence. This catalyst is based on pumice as a carrier, which is different from the catalyst carrier used in the present invention, but it still cannot obtain a catalyst whose active components are eggshell-shaped distributions.

Chang等(Chang June-Cheng，Chou Tse-Chuan.Applied Catalysis A：General，1997，156：193-205.)制备了一种蛋壳型分布的Pd/Al₂O₃催化剂，并应用于异戊二烯的选择性加氢。Gangwal等(Gangwal V R，van der Schaaf J，Kuster BF M，Schouten J C.Catalysis Today，2004，96：223-234.)制备了蛋壳型分布的Pt/活性炭催化剂并应用于乙醇的氧化。虽然它们的催化活性都较高，但其制备都需要对负载条件进行一定的控制才能获得活性组分为蛋壳型分布的贵金属催化剂。而且这些催化剂一般都用于气-液反应，很少用于气-气反应。这种催化剂的活性组分主要分布在载体的外表层，呈蛋壳型分布，在催化剂的内部仍是实心的载体活性炭。从结构上，此种蛋壳型催化剂与本发明制备的蛋壳型催化剂存在根本的区别，因为本发明制备的蛋壳型催化剂是以空心SiO₂为载体，活性组分分布在空心载体的外表面、内表面以及孔道内，而催化剂内部是空腔。Chang et al. (Chang June-Cheng, Chou Tse-Chuan. Applied Catalysis A: General, 1997, 156: 193-205.) prepared a Pd/Al₂ O₃ catalyst with an eggshell distribution and applied it to isoprene Selective hydrogenation of alkenes. Gangwal et al. (Gangwal V R, van der Schaaf J, Kuster BF M, Schouten J C. Catalysis Today, 2004, 96: 223-234.) prepared a Pt/activated carbon catalyst with eggshell distribution and applied it to the oxidation of ethanol. Although their catalytic activities are high, their preparation requires certain control of the loading conditions in order to obtain noble metal catalysts whose active components are eggshell-shaped distributions. Moreover, these catalysts are generally used in gas-liquid reactions, and are rarely used in gas-gas reactions. The active components of this catalyst are mainly distributed on the outer layer of the carrier in an eggshell-shaped distribution, and the inside of the catalyst is still a solid carrier activated carbon. Structurally, this eggshell-type catalyst is fundamentally different from the eggshell-type catalyst prepared by the present invention, because the eggshell-type catalyst prepared by the present invention is based on hollow_SiO as a carrier, and the active components are distributed on the outer surface of the hollow carrier , the inner surface and the pores, while the inside of the catalyst is a cavity.

国内有大量文献(房德仁，等.石油化工，2003，32(1)：5-8；洪传庆，等.燃料化学学报，2001，29(4)：355-359；王兆谦，等.天然气化工，2003，29：16-19.)报道了传统甲醇合成铜-锌催化剂的制备及催化性能。这些催化剂主要是以Al₂O₃为载体，通过活性组分与载体之间的相互作用以及活性组分的催化作用，使得催化加氢制备甲醇得以顺利进行。但是采用此种催化剂，其反应条件要求较高，反应压力一般需要控制在5～20MPa，有的催化剂所需要的反应压力更高，特别是在工业生产甲醇过程中，最高压力要达到150MPa，这就对反应器提出了更高的要求，同时生产能耗也大幅度提高。铜基催化剂是一种低压催化剂，其主要组分为CuO/ZnO/Al₂O₃，是由英国ICI公司和德国Lurgi公司先后研制成功的，操作温度为500～530K，压力却只有5～10MPa，比传统的合成工艺温度低得多，对甲醇反应平衡有利。There are a large number of domestic literature (Fang Deren, et al. Petrochemical, 2003, 32(1): 5-8; Hong Chuanqing, et al. Journal of Fuel Chemistry, 2001, 29(4): 355-359; Wang Zhaoqian, et al. Natural gas chemical industry , 2003, 29:16-19.) reported the preparation and catalytic performance of traditional copper-zinc catalysts for methanol synthesis. These catalysts are mainly based on Al₂ O₃ , and through the interaction between the active component and the support and the catalytic effect of the active component, the catalytic hydrogenation of methanol can be carried out smoothly. However, the use of this catalyst requires higher reaction conditions, and the reaction pressure generally needs to be controlled at 5-20 MPa. Some catalysts require higher reaction pressures, especially in the process of industrial methanol production, where the maximum pressure must reach 150 MPa. Higher requirements are placed on the reactor, and the production energy consumption is also greatly increased. Copper-based catalyst is a low-pressure catalyst whose main component is CuO/ZnO/Al₂ O₃ , which was successfully developed by British ICI company and German Lurgi company. The operating temperature is 500-530K, but the pressure is only 5-10MPa , which is much lower than the traditional synthesis process temperature, which is beneficial to the methanol reaction balance.

以上文献中提到的催化剂制备方法有的只是提高了催化剂活性中心的分散度，但是就整体而言金属活性中心分布比较均匀，在催化剂颗粒内部仍有大量活性中心不能起到催化作用，从而导致金属活性组分的浪费。而有的制备方法虽然能控制活性组分的蛋壳型分布，但其负载条件一般都较为严格，反应条件要求较高，特别是在CO加氢制备甲醇的反应中，采用铜-锌催化剂，整个反应条件需要大幅度提高，其中反应压力要求较高，其所需的最小压力也需要5MPa，同时CO的转化率相对较低。Some of the catalyst preparation methods mentioned in the above documents only improve the dispersion of the catalyst active centers, but on the whole the distribution of the metal active centers is relatively uniform, and there are still a large number of active centers inside the catalyst particles that cannot play a catalytic role, resulting in Waste of metal active components. Although some preparation methods can control the eggshell distribution of active components, the loading conditions are generally stricter and the reaction conditions are more demanding. Especially in the reaction of CO hydrogenation to methanol, copper-zinc catalyst is used. The whole reaction condition needs to be greatly improved, among which the reaction pressure is required to be high, and the required minimum pressure also needs to be 5 MPa, and the conversion rate of CO is relatively low.

本发明所制备的金属催化剂是一种金属活性中心非均匀分布的催化剂，它是以具有空心结构的SiO₂为载体，在其壁上负载一定量的金属制备而成。因此，很容易实现活性组分的蛋壳型分布，而且能大大减少金属的用量，并能充分发挥金属活性组分的催化活性，同时还能有针对性地应用于一些气-液和气-气的快速反应体系。在CO加氢制备甲醇的工艺中，采用以空心SiO₂为载体制备的催化剂，反应压力可以控制在1.5～5.0MPa，反应温度为200～300℃。与传统的铜-锌催化剂相比，反应条件明显降低，且甲醇的选择性以及CO的转化率都有所提高，说明此种催化剂适用于低温、低压下合成甲醇。The metal catalyst prepared by the invention is a catalyst with non-uniform distribution of metal active centers, and it is prepared by using_SiO2 with a hollow structure as a carrier and loading a certain amount of metal on its wall. Therefore, it is easy to realize the eggshell distribution of active components, and can greatly reduce the amount of metal used, and can give full play to the catalytic activity of metal active components, and can also be targetedly applied to some gas-liquid and gas-gas rapid response system. In the process of CO hydrogenation to prepare methanol, the catalyst prepared with hollow_SiO2 as the carrier is used, the reaction pressure can be controlled at 1.5-5.0 MPa, and the reaction temperature is 200-300 °C. Compared with the traditional copper-zinc catalyst, the reaction conditions are significantly lower, and the selectivity of methanol and the conversion rate of CO are improved, indicating that this catalyst is suitable for the synthesis of methanol at low temperature and low pressure.

关于空心结构的SiO₂载体，在本申请人(北京化工大学)先前申请的专利中有详细描述。在中国发明专利申请公布说明书CN 1445311A中，介绍了纳米CaCO₃/SiO₂复合材料的制备方法。以纳米碳酸钙为模板，以硅酸钠为硅源，通过稀盐酸与硅酸钠反应在碳酸钙的表面不仅可以包覆一层SiO₂，还可以根据碳酸钙的颗粒大小和颗粒形状来调控空心二氧化硅的颗粒大小、壁厚和颗粒形状。在中国发明专利申请公布说明书CN 1511785A中，介绍了以纳米碳酸钙为模板，以硅酸钠为硅源制备空心二氧化硅介孔材料的方法，其制备的空心二氧化硅介孔材料粒径为50～120nm，壁厚为10～15nm，平均孔径为2～5nm。在中国发明专利申请200410098068.4中，介绍了由单颗粒空心二氧化硅制备空心二氧化硅团粒，以及空心二氧化硅团粒负载茂金属催化剂，及其在烯烃聚合反应中的应用。而以空心SiO₂为载体负载金属活性组分的蛋壳型催化剂，及其用于CO加氢制备甲醇中，还未见报道。The_SiO2 carrier with a hollow structure is described in detail in the patent previously applied by the applicant (Beijing University of Chemical Technology). In the Chinese invention patent application publication specification CN 1445311A, a preparation method of nano-CaCO₃ /SiO₂ composite material is introduced. Using nano-calcium carbonate as a template and sodium silicate as a silicon source, the surface of calcium carbonate can not only be coated with a layer of SiO₂ through the reaction of dilute hydrochloric acid and sodium silicate, but also can be adjusted according to the particle size and shape of calcium carbonate. Particle size, wall thickness and particle shape of hollow silica. In the publication specification CN 1511785A of the Chinese invention patent application, a method for preparing hollow silica mesoporous materials using nano-calcium carbonate as a template and sodium silicate as a silicon source is introduced. The particle size of the hollow silica mesoporous materials prepared by it is It is 50-120nm, the wall thickness is 10-15nm, and the average pore diameter is 2-5nm. In the Chinese invention patent application 200410098068.4, the preparation of hollow silica aggregates from single-particle hollow silica, the metallocene catalyst supported by hollow silica aggregates, and its application in olefin polymerization were introduced. However, there are no reports on the eggshell-type catalysts that use hollow_SiO2 as a carrier to support metal active components, and their use in the hydrogenation of CO to produce methanol.

发明内容Contents of the invention

本发明的目的是将二氧化硅包覆到作为模板的纳米碳酸钙上以最终制备球状空心或管状空心SiO₂，并以此空心SiO₂为载体的蛋壳型金属催化剂。本发明的另一目的是提供该蛋壳型金属催化剂的制备方法。该催化剂具有良好的金属分散性，并且金属颗粒较小，金属颗粒能分散在空心SiO₂的外表面、内表面以及孔道中，适用于加氢反应制备甲醇的反应。The purpose of the present invention is to coat silicon dioxide on the nano-calcium carbonate as a template to finally prepare spherical hollow or tubular hollow SiO₂ , and use the hollow SiO₂ as a carrier eggshell metal catalyst. Another object of the present invention is to provide a preparation method of the eggshell metal catalyst. The catalyst has good metal dispersibility, and the metal particles are small, and the metal particles can be dispersed on the outer surface, inner surface and pores of the hollow SiO₂ , and are suitable for the hydrogenation reaction to prepare methanol.

本发明涉及一种蛋壳型金属催化剂的载体——空心SiO₂，其具有空心结构，形状为球状或者管状。The invention relates to a carrier of an eggshell metal catalyst—hollow SiO₂ , which has a hollow structure and is spherical or tubular in shape.

本发明涉及以上述空心二氧化硅为载体，采用浸渍法或原位负载法制备蛋壳型金属及其结构表征。The invention relates to the preparation of eggshell metal and its structural characterization by using the above-mentioned hollow silicon dioxide as a carrier and adopting an impregnation method or an in-situ loading method.

本发明还涉及采用上述制备的催化剂应用于CO加氢制备甲醇的反应。The present invention also relates to the application of the catalyst prepared above to the reaction of CO hydrogenation to prepare methanol.

本发明催化剂的技术方案是：The technical scheme of catalyst of the present invention is:

一种蛋壳型金属催化剂，由二氧化硅载体、贵金属和/或过渡金属、可选择的非贵金属助催化剂组成，其中所述载体是空心结构的二氧化硅。以催化剂重量百分比为基准，其组成为0.1％～5.0％的贵金属和/或5.0％～40.0％的过渡金属，0～0.5％的非贵金属助催化剂，60.0％～99.0％的空心二氧化硅载体。其中所述的贵金属选自Pd、Pt、Rh中的一种或几种，所述的过渡金属选自Ni、Cu、Zn中的一种或几种，所述的非贵金属助催化剂选自碱金属、碱土金属、VIB族元素和其他过渡金属中的一种或几种。An eggshell metal catalyst is composed of a silica carrier, a noble metal and/or a transition metal, and an optional non-noble metal cocatalyst, wherein the carrier is silica with a hollow structure. Based on the weight percentage of the catalyst, its composition is 0.1% to 5.0% of noble metals and/or 5.0% to 40.0% of transition metals, 0 to 0.5% of non-noble metal promoters, and 60.0% to 99.0% of hollow silica carriers . Wherein the noble metal is selected from one or more of Pd, Pt, Rh, the transition metal is selected from one or more of Ni, Cu, Zn, and the non-noble metal promoter is selected from alkali One or more of metals, alkaline earth metals, VIB group elements and other transition metals.

本发明中的空心SiO₂载体的制备方法在中国发明专利申请公布说明书CN1445311A和CN 1511785A中有详细的介绍，即以纳米碳酸钙为模板，以硅酸钠为硅源制备空心二氧化硅介孔材料。本申请采用具有空心结构的球状颗粒或者管状颗粒SiO₂载体，具有较大的孔容和比表面积，并具有排列规则的孔道。其中球状空心SiO₂的比表面积为500～1500m²/g，优选为500～1000m²/g；孔容为0.3～1.0mL/g，优选为0.5～0.9mL/g。而管状空心SiO₂颗粒的比表面积为400～1000m²/g，优选为500～800m²/g；孔容为0.3～1.0mL/g，优选为0.5～0.8mL/g；直径为80～150nm，长度为1～3μm。The preparation method of the hollow_SiO2 carrier in the present invention is described in detail in the Chinese Invention Patent Application Publication Specification CN1445311A and CN 1511785A, that is, using nano-calcium carbonate as a template and sodium silicate as a silicon source to prepare hollow silica mesoporous Material. This application adopts a spherical particle or tubular particle_SiO2 carrier with a hollow structure, which has a large pore volume and specific surface area, and has regularly arranged pores. The specific surface area of spherical hollow SiO₂ is 500-1500m² /g, preferably 500-1000m² /g; the pore volume is 0.3-1.0mL/g, preferably 0.5-0.9mL/g. The specific surface area of tubular hollow SiO₂ particles is 400-1000m² /g, preferably 500-800m² /g; the pore volume is 0.3-1.0mL/g, preferably 0.5-0.8mL/g; the diameter is 80-150nm , with a length of 1 to 3 μm.

本发明催化剂的制备方法的技术方案是：The technical scheme of the preparation method of catalyst of the present invention is:

一种蛋壳型金属催化剂的制备方法，依次包括如下步骤：将空心二氧化硅载体加入到至少一种贵金属和/或至少一种过渡金属的醋酸盐、硝酸盐、硫酸盐或卤化物的溶液中，并与之充分混合，温度控制在20～80℃；负载结束后进行过滤，以10～20℃/min升温到80～130℃，干燥3～15h；将干燥后的粉体筛分，最后以1～5℃/min升温到400～500℃，煅烧3～12h。A method for preparing an eggshell metal catalyst, comprising the steps of: adding a hollow silica carrier to a solution of acetate, nitrate, sulfate or halide of at least one noble metal and/or at least one transition metal and fully mixed with it, the temperature is controlled at 20-80°C; after the loading is completed, filter, raise the temperature to 80-130°C at 10-20°C/min, and dry for 3-15 hours; sieve the dried powder, Finally, the temperature is raised to 400-500°C at 1-5°C/min, and calcined for 3-12 hours.

一种蛋壳型金属催化剂的制备方法，依次包括如下步骤：采用聚甲基丙烯酸甲酯作有机模板，正硅酸乙酯为硅源，至少一种贵金属和/或至少一种过渡金属的醋酸盐、硝酸盐、硫酸盐或卤化物为前驱体，与卤化物或者盐相应的酸为水解剂和沉淀剂，控制pH值在1～3之间，水解10～20h至溶液澄清透明；过滤，然后以10～20℃/min升温到95～115℃，干燥5～10h；将干燥后的粉体筛分，最后以1～5℃/min升温到400～600℃，煅烧3～7h。A method for preparing an eggshell-type metal catalyst, comprising the following steps in sequence: using polymethyl methacrylate as an organic template, tetraethyl orthosilicate as a silicon source, and acetic acid of at least one noble metal and/or at least one transition metal Salt, nitrate, sulfate or halide is used as the precursor, and the acid corresponding to the halide or salt is used as the hydrolyzing agent and precipitating agent. The pH value is controlled between 1 and 3, and the solution is hydrolyzed for 10 to 20 hours until the solution is clear and transparent; filtering, Then heat up to 95-115°C at 10-20°C/min, and dry for 5-10 hours; sieve the dried powder, and finally heat up to 400-600°C at 1-5°C/min, and calcinate for 3-7 hours.

一种蛋壳型金属催化剂的制备方法，依次包括如下步骤：将过渡金属的醋酸盐、硝酸盐、硫酸盐或卤化物的溶液加入到空心SiO₂载体的胶体溶液中，并与之充分搅拌，同时滴加选自Na₂CO₃、NaHCO₃或者NH₃HCO₃的沉淀剂，搅拌速度控制在400～600r/min，维持体系的pH值在8～10之间，搅拌时间为12～24h；负载结束后进行过滤，然后以10～20℃/min升温到90～110℃，干燥3～12h；干燥后的粉体用标准筛进行筛分，将筛分后的粉体进行煅烧处理，煅烧温度为450～500℃，升温速率为1～5℃/min，煅烧时间为3～10h。A preparation method of an eggshell-type metal catalyst, comprising the steps in turn: adding a solution of acetate, nitrate, sulfate or halide of a transition metal to a hollow_SiO carrier colloidal solution, and fully stirring with it, At the same time, drop the precipitant selected from Na₂ CO₃ , NaHCO₃ or NH₃ HCO₃ , the stirring speed is controlled at 400-600r/min, the pH value of the system is maintained between 8-10, and the stirring time is 12-24h; Filter after loading, then heat up to 90-110°C at 10-20°C/min, and dry for 3-12 hours; the dried powder is sieved with a standard sieve, and the sieved powder is calcined. The temperature is 450-500°C, the heating rate is 1-5°C/min, and the calcination time is 3-10h.

一种蛋壳型金属催化剂的制备方法，依次包括如下步骤：将按照上述3种方法制得的催化剂，进一步加入到非贵金属的卤化物、硝酸盐或碳酸盐的溶液中，并与之充分混合，温度控制在20～80℃；负载结束后进行过滤，以10～20℃/min升温到90～110℃，干燥3～12h；将干燥后的粉体筛分，最后以1～5℃/min升温到400～450℃，煅烧3～10h。A method for preparing an eggshell-type metal catalyst, comprising the following steps in turn: adding the catalyst prepared by the above three methods to a solution of non-noble metal halides, nitrates or carbonates, and fully mixing with it , the temperature is controlled at 20-80°C; after the load is finished, filter, heat up to 90-110°C at 10-20°C/min, and dry for 3-12 hours; sieve the dried powder, and finally use 1-5°C/min Min is heated to 400-450°C, and calcined for 3-10 hours.

本发明还给出了前述催化剂应用于CO加氢制备甲醇的工艺条件，即反应温度200～300℃，反应压力1.5～5.0MPa，H₂与CO的体积比为(1.5～3.0)∶1。The present invention also provides the process conditions for the aforementioned catalysts to be used in CO hydrogenation to prepare methanol, that is, the reaction temperature is 200-300° C., the reaction pressure is 1.5-5.0 MPa, and the volume ratio of_H2 to CO is (1.5-3.0):1.

下面对本发明的制备方法进行详细描述：The preparation method of the present invention is described in detail below:

将一定量的贵金属盐或者卤化物配制成水溶液，对于贵金属卤化物，一般采用相应的酸和去离子水进行溶解，溶解过程需要加热、沸腾，直至溶液澄清、透明。称取一定量的空心二氧化硅载体，加入到上述的贵金属溶液中，可以同时搅拌，搅拌时间一般控制在2～15h，优选5～10h；同时控制负载体系的温度，温度控制在20～80℃，优选30～50℃。在负载体系负载结束以后，进行过滤、干燥、筛分和煅烧处理，即可得到负载贵金属的蛋壳型催化剂。本方法的干燥处理温度是80～130℃，干燥时间为3～15h，升温速率为10～20℃/min。干燥后的粉体用标准筛进行筛分，将筛分后的粉体进行煅烧处理，煅烧温度为400～500℃，升温速率为1～5℃/min，煅烧时间为3～12h。A certain amount of noble metal salt or halide is formulated into an aqueous solution. For noble metal halides, the corresponding acid and deionized water are generally used for dissolution. The dissolution process requires heating and boiling until the solution is clear and transparent. Weigh a certain amount of hollow silica carrier, add it to the above precious metal solution, and stir at the same time. The stirring time is generally controlled at 2-15 hours, preferably 5-10 hours; at the same time, the temperature of the supporting system is controlled at 20-80 °C, preferably 30-50 °C. After the supporting system is loaded, filter, dry, sieve and calcinate to obtain the eggshell catalyst loaded with precious metals. The drying treatment temperature of the method is 80-130° C., the drying time is 3-15 hours, and the heating rate is 10-20° C./min. The dried powder is sieved with a standard sieve, and the sieved powder is calcined at a temperature of 400-500° C., a heating rate of 1-5° C./min, and a calcination time of 3-12 hours.

本发明还提供了蛋壳型贵金属催化剂的另一种制备方法。即采用一定量的聚甲基丙烯酸甲酯作有机模板，按照比例加入一定量的正硅酸乙酯为硅源，以贵金属盐或卤化物作为贵金属催化剂的前驱体，与贵金属盐或卤化物相应的酸为水解剂和沉淀剂，在室温下搅拌水解、负载，经过滤、干燥、筛分和煅烧处理，即可得到蛋壳型贵金属催化剂。本方法的聚甲基丙烯酸甲酯乳液的质量分数为25％～45％，正硅酸乙酯中Si的质量分数为28％，在贵金属氯化物中加入去离子水和相应的酸，反应体系的pH值一般控制在1～3之间，加热、沸腾，水解10～20h，直至溶液澄清、透明，并待其降至室温；过滤，干燥，干燥温度为95～115℃，升温速率为10～20℃/min，干燥时间为5～10h；将干燥后的粉体筛分后煅烧，煅烧温度为400～600℃，升温速率为1～5℃/min，煅烧时间为3～7h，即可得到蛋壳型贵金属催化剂。The invention also provides another preparation method of the eggshell type noble metal catalyst. That is, a certain amount of polymethyl methacrylate is used as the organic template, a certain amount of tetraethyl orthosilicate is added in proportion as the silicon source, and the noble metal salt or halide is used as the precursor of the noble metal catalyst. The acid is a hydrolyzing agent and a precipitating agent, which is stirred and hydrolyzed at room temperature, loaded, filtered, dried, sieved and calcined to obtain an eggshell-type precious metal catalyst. The mass fraction of the polymethyl methacrylate emulsion of this method is 25%～45%, and the mass fraction of Si in tetraethyl orthosilicate is 28%, and deionized water and corresponding acid are added in the noble metal chloride, and the reaction system Generally control the pH value between 1 and 3, heat, boil, and hydrolyze for 10 to 20 hours until the solution is clear and transparent, and wait for it to drop to room temperature; filter and dry, the drying temperature is 95 to 115 ° C, and the heating rate is 10 ~20°C/min, drying time is 5~10h; the dried powder is sieved and then calcined, the calcining temperature is 400~600°C, the heating rate is 1~5°C/min, and the calcining time is 3~7h, that is Eggshell-type noble metal catalysts are available.

本发明还提供了一种蛋壳型贵金属催化剂的制备方法。称取一定量的贵金属盐或者卤化物配制成水溶液，得到所需的贵金属盐溶液。称取一定量的球状空心SiO₂载体，然后将此溶液缓慢滴入球状空心二氧化硅载体粉末里，刚好形成糊状且没有多余的液体出现。室温下放置0.5～3.0h后置于80～110℃下干燥8～12h，等水分挥发完后将获得的干粉在450～550℃下煅烧2～4h，其升温速率为2～8℃/min，即可得到蛋壳型贵金属催化剂。The invention also provides a preparation method of the eggshell type noble metal catalyst. A certain amount of noble metal salt or halide is weighed to prepare an aqueous solution to obtain the desired noble metal salt solution. Weigh a certain amount of spherical hollow_SiO2 carrier, and then slowly drop this solution into the spherical hollow silica carrier powder, just forming a paste and no excess liquid appears. Place at room temperature for 0.5-3.0 hours, then dry at 80-110°C for 8-12 hours, and after the moisture evaporates, calcinate the obtained dry powder at 450-550°C for 2-4 hours, and the heating rate is 2-8°C/min , the eggshell-type noble metal catalyst can be obtained.

以上述制备的蛋壳型贵金属催化剂为载体，进一步负载非贵金属组分作为助催化剂，从而制得非贵金属助催化的蛋壳型贵金属催化剂。将一定量的非贵金属(如碱金属、碱土金属或者过渡金属)的卤化物、硝酸盐或者碳酸盐溶解，配成一定浓度的溶液。取一定量的上述非贵金属盐溶液，再称取一定量的上述蛋壳型贵金属催化剂，进行非贵金属的负载。负载时可以进行搅拌，搅拌时间为2～15h，负载温度为20～80℃，优选30～50℃。在负载结束后，进行过滤、干燥、筛分和煅烧处理，即可得到负载有非贵金属助催化剂的蛋壳型贵金属催化剂。本方法的干燥处理温度是90～110℃，干燥时间为3～12h，升温速率为10～20℃/min。干燥后的粉体用标准筛进行筛分，将筛分后的粉体进行煅烧处理，煅烧温度为400～450℃，升温速率为1～5℃/min，煅烧时间为3～10h，即可得到非贵金属为助催化剂的蛋壳型贵金属催化剂。The above-prepared eggshell-type noble metal catalyst is used as a carrier, and a non-noble metal component is further supported as a cocatalyst, thereby preparing an eggshell-type noble metal catalyst promoted by a non-noble metal. Dissolve a certain amount of halides, nitrates or carbonates of non-precious metals (such as alkali metals, alkaline earth metals or transition metals) to prepare a solution with a certain concentration. A certain amount of the above-mentioned non-precious metal salt solution is taken, and then a certain amount of the above-mentioned eggshell-type precious metal catalyst is weighed to carry out non-precious metal loading. Stirring can be carried out during loading, the stirring time is 2-15 hours, and the loading temperature is 20-80°C, preferably 30-50°C. After the loading is finished, filter, dry, sieve and calcinate to obtain an eggshell-type noble metal catalyst loaded with a non-noble metal co-catalyst. The drying treatment temperature of the method is 90-110° C., the drying time is 3-12 hours, and the heating rate is 10-20° C./min. The dried powder is screened with a standard sieve, and the screened powder is calcined at a temperature of 400-450°C, a heating rate of 1-5°C/min, and a calcining time of 3-10 hours. The eggshell type noble metal catalyst with non-noble metal as promoter is obtained.

本发明还提供了一种蛋壳型过渡金属催化剂的制备方法。将一定量的过渡金属的醋酸盐、硝酸盐、硫酸盐或氯化物用去离子水溶解，再加入一定量的空心SiO₂载体，进行搅拌浸渍负载，同时滴加选自Na₂CO₃、NaHCO₃或者NH₃HCO₃的沉淀剂，搅拌速度控制在400～600r/min，维持体系的pH值在8～10之间，搅拌时间为12～24h。负载后，进行过滤、干燥、筛分和煅烧处理，即可得到负载镍的蛋壳型催化剂。本方法的干燥处理温度为90～110℃，干燥时间为3～12h，升温速率为10～20℃/min。干燥后的粉体用标准筛进行筛分，将筛分后的粉体进行煅烧处理，煅烧温度为400～450℃，升温速率为1～5℃/min，煅烧时间为3～10h。The invention also provides a preparation method of the eggshell transition metal catalyst. Dissolve a certain amount of transition metal acetate, nitrate, sulfate or chloride with deionized water, then add a certain amount of hollow SiO₂ carrier, carry out stirring impregnation loading, and dropwise add selected from Na₂ CO₃ , For the precipitant of NaHCO₃ or NH₃ HCO₃ , the stirring speed is controlled at 400-600r/min, the pH value of the system is maintained between 8-10, and the stirring time is 12-24h. After loading, filter, dry, sieve and calcinate to obtain the nickel-loaded eggshell catalyst. The drying treatment temperature of the method is 90-110° C., the drying time is 3-12 hours, and the heating rate is 10-20° C./min. The dried powder is sieved with a standard sieve, and the sieved powder is calcined at a temperature of 400-450°C, a heating rate of 1-5°C/min, and a calcining time of 3-10 hours.

本发明提供了一种蛋壳型双金属催化剂的制备方法，下面以铜-锌催化剂为例进行描述。将一定量的铜和锌的硝酸盐、氯化物、硫酸盐或者醋酸盐用去离子水溶解，配制成混合溶液，将一定量的空心SiO₂载体用适量的去离子水配制成胶体，将铜盐和锌盐的混合溶液加入到SiO₂胶体中，搅拌，搅拌速度为400～600r/min，同时滴加一定浓度的Na₂CO₃溶液，维持体系的pH值在8～10之间，搅拌时间为5～12h。负载后，进行过滤、干燥、筛分和煅烧处理，即可得到负载Cu-Zn的蛋壳型催化剂。本方法的干燥处理温度为90～110℃，干燥时间为3～12h，升温速率为10～20℃/min。干燥后的粉体用标准筛进行筛分，将筛分后的粉体进行煅烧处理，煅烧温度为450～500℃，升温速率为1～5℃/min，煅烧时间为3～10h。The invention provides a method for preparing an eggshell-type bimetallic catalyst, which will be described below taking a copper-zinc catalyst as an example. A certain amount of copper and zinc nitrate, chloride, sulfate or acetate is dissolved in deionized water to prepare a mixed solution, and a certain amount of hollow_SiO2 carrier is prepared into a colloid with an appropriate amount of deionized water. Add the mixed solution of copper salt and zinc salt into the SiO₂ colloid and stir at a stirring speed of 400-600r/min. At the same time, add a certain concentration of Na₂ CO₃ solution dropwise to maintain the pH value of the system between 8-10. Stirring time is 5~12h. After loading, filter, dry, sieve and calcinate to obtain the Cu-Zn-loaded eggshell catalyst. The drying treatment temperature of the method is 90-110° C., the drying time is 3-12 hours, and the heating rate is 10-20° C./min. The dried powder is sieved with a standard sieve, and the sieved powder is calcined at a temperature of 450-500°C, a heating rate of 1-5°C/min, and a calcining time of 3-10 hours.

本发明催化剂用于CO加氢反应制备甲醇的工艺条件是：反应温度200～300℃，反应压力1.5～5.0MPa，H₂与CO的体积比为(1.5～3.0)∶1。对反应活性进行测试的方法为：首先将一定量的催化剂装填于微型固定床反应器中，采用高纯氢进行还原，还原温度为380～420℃，还原升温速率为2～8℃/min，氢气流量为20～40mL/min，还原时间为2～5h。还原结束后，将温度降至反应温度，同时通入反应气体CO和H₂，H₂与CO的体积比为(1.5～3.0)∶1，同时将反应压力调至1.5～5.0MPa，反应产物由气相色谱在线进行分析。The process conditions for the catalyst of the present invention to be used in CO hydrogenation reaction to prepare methanol are: reaction temperature 200-300°C, reaction pressure 1.5-5.0MPa, volume ratio of_H2 to CO (1.5-3.0):1. The method for testing the reaction activity is as follows: firstly, a certain amount of catalyst is loaded in a micro-fixed bed reactor, and high-purity hydrogen is used for reduction, the reduction temperature is 380-420°C, the reduction heating rate is 2-8°C/min, It is 20-40mL/min, and the reduction time is 2-5h. After the reduction, lower the temperature to the reaction temperature, and simultaneously feed the reaction gases CO and H₂ , the volume ratio of H₂ to CO is (1.5-3.0): 1, and at the same time adjust the reaction pressure to 1.5-5.0 MPa, the reaction product Analysis was performed online by gas chromatography.

本发明提供的蛋壳型金属催化剂，特别适合于CO催化加氢制备甲醇的反应。与传统硅胶为载体制备的催化剂相比较，其反应压力显著降低，此种催化剂的反应压力只需要1.5～5.0MPa，而传统的催化剂所需压力最小也要5MPa。同时，CO的转化率显著提高，CO的单程最高转化率可达到68％，甲醇的选择性为100％；而一般的催化剂的单程最高转化率为40％左右，甲醇的选择性为95％左右。因此，采用空心SiO₂作载体的催化加氢催化剂，不仅可以降低反应条件，还可以提高CO的转化率和甲醇的选择性。The eggshell metal catalyst provided by the invention is particularly suitable for the reaction of CO catalytic hydrogenation to prepare methanol. Compared with the catalyst prepared with traditional silica gel as the carrier, the reaction pressure is significantly lower. The reaction pressure of this catalyst only needs 1.5-5.0 MPa, while the minimum pressure required by the traditional catalyst is 5 MPa. At the same time, the conversion rate of CO is significantly improved, the highest single-pass conversion rate of CO can reach 68%, and the selectivity of methanol is 100%; while the maximum single-pass conversion rate of general catalysts is about 40%, and the selectivity of methanol is about 95%. . Therefore, the use of hollow_SiO2 as a catalytic hydrogenation catalyst can not only reduce the reaction conditions, but also improve the conversion of CO and the selectivity of methanol.

附图说明Description of drawings

图1是球状空心二氧化硅的TEM照片。Figure 1 is a TEM photograph of spherical hollow silica.

图2是管状空心二氧化硅的TEM照片。Fig. 2 is a TEM photograph of tubular hollow silica.

图3是球状空心二氧化硅为载体的蛋壳型贵金属钯催化剂的TEM照片。Fig. 3 is the TEM photo of the eggshell type noble metal palladium catalyst with spherical hollow silica as the carrier.

图4是球状空心二氧化硅为载体的蛋壳型贵金属铂催化剂的TEM照片。Figure 4 is a TEM photo of the eggshell-type noble metal platinum catalyst supported by spherical hollow silica.

图5是管状空心二氧化硅为载体的蛋壳型贵金属铂催化剂的TEM照片。Fig. 5 is a TEM photograph of an eggshell-type noble metal platinum catalyst supported by tubular hollow silica.

图6是球状空心二氧化硅为载体的蛋壳型过渡金属镍催化剂的TEM照片。Figure 6 is a TEM photograph of an eggshell-type transition metal nickel catalyst supported by spherical hollow silica.

图7是反应温度对蛋壳型镍催化剂在CO加氢反应中CO转化率和产物甲醇选择性的影响。Figure 7 shows the effect of reaction temperature on the conversion of CO and the selectivity of product methanol in the hydrogenation of CO over the eggshell nickel catalyst.

具体实施方式Detailed ways

下面结合具体实施例对本发明作进一步的说明。The present invention will be further described below in conjunction with specific examples.

实施例1Example 1

将北京化工大学教育部超重力工程研究中心采用超重力技术制备的立方形纳米碳酸钙配制成浓度为0.8mol/L的悬浮液，取1000mL纳米碳酸钙悬浮液置于反应器中，并开始加热升温和搅拌，搅拌速度控制在400～500r/min；配制浓度为0.68mol/L的硅酸钠溶液500mL和10wt％的稀盐酸溶液。在温度升到80℃时，开始加入硅酸钠溶液，同时加入稀盐酸，调节体系的pH在8.5～9.5之间，生成CaCO₃/SiO₂核-壳结构材料。待硅酸钠溶液全部滴加到体系中后，停止加酸，并在此反应温度下搅拌陈化，陈化时间控制在4h，以便使得SiO₂在CaCO₃表面沉积、固化。陈化后的浆料经过过滤、洗涤，在105℃下干燥12h，粉碎后用250目标准筛筛分，然后在马弗炉内煅烧，升温速度4℃/min，煅烧温度600～700℃，煅烧时间6h。经过煅烧后的粉体，用20wt％的稀盐酸500mL溶解，去除CaCO₃模板，并在pH值小于1的情况下溶解5h；最后经过洗涤、过滤，在105℃下干燥，筛分，即得到球状空心二氧化硅颗粒。球状空心二氧化硅颗粒的比表面积为500～1500m²/g，孔容为0.3～1.0mL/g。图1是该球状空心二氧化硅的TEM照片。The cubic nano-calcium carbonate prepared by the super-gravity engineering research center of the Ministry of Education of Beijing University of Chemical Technology was prepared into a suspension with a concentration of 0.8mol/L, and 1000mL of the nano-calcium carbonate suspension was placed in the reactor and started to heat Warming up and stirring, the stirring speed is controlled at 400-500r/min; 500mL of sodium silicate solution with a concentration of 0.68mol/L and 10wt% dilute hydrochloric acid solution are prepared. When the temperature rises to 80°C, start to add sodium silicate solution, and at the same time add dilute hydrochloric acid to adjust the pH of the system between 8.5 and 9.5 to generate a CaCO₃ /SiO₂ core-shell structure material. After all the sodium silicate solution is added dropwise to the system, stop adding acid, and age with stirring at the reaction temperature. The aging time is controlled at 4 hours, so that SiO₂ is deposited and solidified on the surface of CaCO₃ . The aged slurry is filtered, washed, dried at 105°C for 12 hours, crushed and sieved with a 250-mesh standard sieve, and then calcined in a muffle furnace with a heating rate of 4°C/min and a calcination temperature of 600-700°C. Calcination time 6h. The calcined powder was dissolved with 500mL of 20wt% dilute hydrochloric acid to remove the CaCO₃ template, and dissolved for 5h at a pH value of less than 1; finally washed, filtered, dried at 105°C, and sieved to obtain Spherical hollow silica particles. The spherical hollow silica particles have a specific surface area of 500-1500m² /g and a pore volume of 0.3-1.0mL/g. Fig. 1 is a TEM photograph of the spherical hollow silica.

实施例2Example 2

将北京化工大学教育部超重力工程研究中心采用超重力技术制备的针状纳米碳酸钙配制成浓度为0.8mol/L的悬浮液，取1000mL纳米碳酸钙悬浮液置于反应器中，进行搅拌，搅拌速度控制在400～500r/min；按照SiO₂/CaCO₃质量比为0.2的比例称取26.7g的正硅酸乙酯(含Si质量分数为28％)用乙醇溶解，将正硅酸乙酯的乙醇溶液加入到碳酸钙浆料中，再加入100mL的17wt％的浓氨水，在室温下搅拌12h。反应后的浆料经过过滤、洗涤，在105℃下干燥12h，粉碎后用250目标准筛筛分，然后在马弗炉内煅烧，升温速度4℃/min，煅烧温度600～700℃，煅烧时间6h。经过煅烧后的粉体，用20wt％的稀盐酸500mL溶解，去除CaCO₃模板，并在pH值小于1的情况下溶解5h；最后经过洗涤、过滤，在105℃下干燥，筛分，即得到管状空心二氧化硅颗粒。管状空心SiO₂颗粒的比表面积为400～1000m²/g，孔容为0.3～1.0mL/g，直径为80～150nm，长度为1～3μm。图2是该管状空心二氧化硅的TEM照片。The needle-shaped nano-calcium carbonate prepared by the high-gravity technology of the Beijing University of Chemical Technology High Gravity Engineering Research Center is formulated into a suspension with a concentration of 0.8mol/L, and 1000mL of the nano-calcium carbonate suspension is placed in the reactor and stirred. The stirring speed is controlled at 400-500r/min; according to the ratio of SiO₂ /CaCO₃ mass ratio of 0.2, weigh 26.7g of tetraethyl orthosilicate (containing 28% Si by mass fraction) and dissolve it in ethanol. The ethanol solution of the ester was added to the calcium carbonate slurry, and then 100 mL of 17 wt % concentrated ammonia water was added, and stirred at room temperature for 12 h. After the reaction, the slurry was filtered and washed, dried at 105°C for 12 hours, crushed and sieved with a 250-mesh standard sieve, and then calcined in a muffle furnace with a heating rate of 4°C/min and a calcining temperature of 600-700°C. Time 6h. The calcined powder was dissolved with 500mL of 20wt% dilute hydrochloric acid to remove the CaCO₃ template, and dissolved for 5h at a pH value of less than 1; finally washed, filtered, dried at 105°C, and sieved to obtain Tubular hollow silica particles. The tubular hollow SiO₂ particles have a specific surface area of 400-1000m² /g, a pore volume of 0.3-1.0mL/g, a diameter of 80-150nm, and a length of 1-3μm. Fig. 2 is a TEM photograph of the tubular hollow silica.

实施例3Example 3

称取0.1666g PdCl₂固体粉末，加入10mL去离子水和10mL 35％的浓盐酸，摇匀后进行加热溶解，加热至沸腾，直至溶液变得澄清、透明。将PdCl₂溶液冷却至室温，称取2g由实施例1制备的球状空心SiO₂载体，加入到PdCl₂溶液中，同时开始搅拌、浸渍。搅拌时间为12h，控制负载温度为35℃左右，然后进行真空过滤，并经过洗涤以除去未负载上的Pd²⁺，过滤后的滤饼于120℃下干燥，升温速率为10℃/min，干燥时间为12h。干燥后的粉体用250目标准筛筛分，将筛分后的粉体进行煅烧，煅烧温度为450℃，升温速率为1℃/min，煅烧时间为6h，即可得到Pd负载质量分数为3.35％的蛋壳型贵金属钯催化剂。图3是该催化剂的TEM照片。Weigh 0.1666g of PdCl₂ solid powder, add 10mL of deionized water and 10mL of 35% concentrated hydrochloric acid, shake well, heat to dissolve, and heat to boiling until the solution becomes clear and transparent. Cool the PdCl₂ solution to room temperature, weigh 2 g of the spherical hollow SiO₂ carrier prepared in Example 1, add it to the PdCl₂ solution, and start stirring and impregnating at the same time. The stirring time is 12 hours, the loading temperature is controlled at about 35°C, and then vacuum filtration is carried out and washed to remove unloaded Pd²⁺ . The filtered cake is dried at 120°C, and the heating rate is 10°C/min. The drying time is 12h. The dried powder is sieved with a 250-mesh standard sieve, and the sieved powder is calcined at a temperature of 450 °C, a heating rate of 1 °C/min, and a calcining time of 6 h, and the mass fraction of Pd loaded can be obtained as 3.35% eggshell type precious metal palladium catalyst. Figure 3 is a TEM photo of the catalyst.

实施例4Example 4

称取0.149g的Ca(NO₃)₂·4H₂O，置于50mL的烧杯内加入少量的去离子水溶解，全部转移到100mL的容量瓶中，用少量的去离子水多次洗涤烧杯，每次洗涤后的溶液全部转移到容量瓶中，最后向容量瓶滴加去离子水直至刻度，然后摇匀，就可以得到浓度为0.00631mol/L的Ca(NO₃)₂溶液。称取0.4g由实施例3所制备的Pd质量分数为3.35％的蛋壳型贵金属Pd催化剂，将其置于50mL的烧杯内，用10mL移液管移取10mL 0.00631mol/L的Ca(NO₃)₂溶液，再加入少量的去离子水，使得催化剂充分浸渍，同时搅拌，搅拌时间为5h。最后加热蒸发，把体系中的水分全部蒸发掉，然后在105℃下干燥10h，升温速率为10℃/min，干燥后的滤饼用250目标准筛筛分，筛分后的粉体于450℃煅烧6h，升温速率为1℃/min。煅烧结束后即可得到以碱土金属钙为助催化剂、钙质量分数为0.5％的蛋壳型贵金属钯催化剂。Weigh 0.149g of Ca(NO₃ )₂ 4H₂ O, put it in a 50mL beaker, add a small amount of deionized water to dissolve, transfer all of it to a 100mL volumetric flask, wash the beaker with a small amount of deionized water several times, The solution after each washing was all transferred to a volumetric flask, and finally deionized water was added dropwise to the volumetric flask until the mark was reached, and then shaken to obtain a Ca(NO₃ )₂ solution with a concentration of 0.00631 mol/L. Take by weighing 0.4g the eggshell type precious metal Pd catalyst that the Pd mass fraction prepared by embodiment 3 is 3.35%, it is placed in the beaker of 50mL, pipette the Ca(NO₃ )₂ solution, and then add a small amount of deionized water, so that the catalyst is fully impregnated, while stirring, the stirring time is 5h. Finally, heat and evaporate to evaporate all the water in the system, and then dry at 105°C for 10h with a heating rate of 10°C/min. The dried filter cake is sieved with a 250-mesh standard sieve, and the sieved powder is sieved at 450 ℃ for 6 hours, and the heating rate is 1 ℃/min. After the calcination is finished, an eggshell-type noble metal palladium catalyst with the alkaline earth metal calcium as the cocatalyst and a calcium mass fraction of 0.5% can be obtained.

实施例5Example 5

称取0.125g的Li₂CO₃，置于50mL的烧杯内加入少量的去离子水溶解，全部转移到100mL的容量瓶中，用少量的去离子水多次洗涤烧杯，每次洗涤后的溶液全部转移到容量瓶中，最后向容量瓶滴加去离子水直至刻度，然后摇匀，就可以得到浓度为0.02557mol/L的Li₂CO₃溶液。称取0.5g由实施例3所制备的Pd质量分数为3.35％的蛋壳型贵金属Pd催化剂，将其置于50mL的烧杯内，用移液管移取6mL上述Li₂CO₃溶液，再加入少量的去离子水，使得催化剂充分浸渍，同时搅拌，搅拌时间为5h。最后加热蒸发，把体系中的水分全部蒸发掉，然后在105℃下干燥10h，升温速率为10℃/min，干燥后的滤饼用250目标准筛筛分，筛分后的粉体于450℃煅烧6h，升温速率为1℃/min。煅烧结束后即可得到以碱金属锂为助催化剂、锂的质量分数为0.5％的蛋壳型贵金属钯催化剂。Weigh 0.125g of Li₂ CO₃ , put it into a 50mL beaker and add a small amount of deionized water to dissolve it, transfer it all to a 100mL volumetric flask, wash the beaker with a small amount of deionized water several times, and the solution after each washing Transfer everything to a volumetric flask, and finally add deionized water to the volumetric flask dropwise to the mark, and then shake well to obtain a Li₂ CO₃ solution with a concentration of 0.02557 mol/L. Weigh 0.5g of the eggshell-type noble metal Pd catalyst with a Pd mass fraction of 3.35% prepared in Example 3, place it in a 50mL beaker_, pipette 6mL of the above_Li2CO3 solution, and then add A small amount of deionized water is used to fully impregnate the catalyst while stirring for 5 hours. Finally, heat and evaporate to evaporate all the water in the system, and then dry at 105°C for 10h with a heating rate of 10°C/min. The dried filter cake is sieved with a 250-mesh standard sieve, and the sieved powder is sieved at 450 ℃ for 6 hours, and the heating rate is 1 ℃/min. After the calcination is finished, an eggshell-type noble metal palladium catalyst with the alkali metal lithium as the cocatalyst and the mass fraction of lithium being 0.5% can be obtained.

实施例6Example 6

称取0.1343g PdCl₂固体粉末，加入10mL去离子水和10mL浓盐酸，加热溶解，加热至沸腾，直至溶液澄清、透明；称取25g质量分数为40％的聚甲基丙烯酸甲酯，将其转移至500mL的容量瓶中，加入200mL去离子水，再加入16.4g的Si质量分数为28％的正硅酸乙酯，最后将PdCl₂溶液的加到上述体系中，同时滴加适量的稀盐酸，使反应体系的pH值维持在1左右，在室温下搅拌水解，水解时间为12h。由于体系中的盐酸与正硅酸乙酯反应生成SiO₂，因此盐酸起到水解剂和沉淀剂的作用，并且生成的SiO₂和Pd²⁺充分混合，沉积在聚甲基丙烯酸甲酯的表面，生成核壳结构，贵金属Pd就负载到球状SiO₂载体上。在反应结束后，经过滤，滤饼在105℃下干燥10h，升温速率为10℃/min，干燥后的滤饼经过250目标准筛筛分后，于450℃煅烧，煅烧时间为6h，升温速率为1℃/min，即可得到负载贵金属钯的蛋壳型贵金属催化剂。Weigh 0.1343g PdCl_solid powder, add 10mL deionized water and 10mL concentrated hydrochloric acid, heat to dissolve, and heat to boiling until the solution is clear and transparent; weigh 25g of polymethyl methacrylate with a mass fraction of 40%, and Transfer to a 500mL volumetric flask, add 200mL of deionized water, then add 16.4g of tetraethylorthosilicate with a Si mass fraction of 28%, and finally add the_PdCl2 solution to the above system, and at the same time add an appropriate amount of dilute hydrochloric acid to keep the pH value of the reaction system at about 1, stir and hydrolyze at room temperature, and the hydrolysis time is 12 hours. Since the hydrochloric acid in the system reacts with tetraethyl orthosilicate to generate SiO₂ , hydrochloric acid acts as a hydrolysis agent and a precipitant, and the generated SiO₂ and Pd²⁺ are fully mixed and deposited on the surface of polymethyl methacrylate , to generate a core-shell structure, and the noble metal Pd is loaded on the spherical SiO₂ carrier. After the reaction, after filtration, the filter cake was dried at 105°C for 10 hours at a heating rate of 10°C/min. After the dried filter cake was sieved through a 250-mesh standard sieve, it was calcined at 450°C for 6 hours. At a rate of 1° C./min, an eggshell-type noble metal catalyst loaded with noble metal palladium can be obtained.

实施例7Example 7

称取0.0560g的H₂PtCl₆·6H₂O固体溶于10mL去离子水中，然后加入1mL35％的浓盐酸。将0.5g由实施例1制备的球状空心二氧化硅载体加到上述溶液中，静置浸渍12h后过滤，洗涤除去未负载的铂离子，滤饼于80℃下干燥，升温速率为10℃/min。最后于500℃下煅烧3h，其升温速率为1℃/min，即可得到负载铂的蛋壳型贵金属催化剂。图4是该催化剂的TEM照片。Weigh 0.0560 g of H₂ PtCl₆ ·6H₂ O solid and dissolve it in 10 mL of deionized water, then add 1 mL of 35% concentrated hydrochloric acid. Add 0.5 g of the spherical hollow silica carrier prepared in Example 1 to the above solution, let stand and soak for 12 hours, then filter, wash to remove unsupported platinum ions, and dry the filter cake at 80°C with a heating rate of 10°C/ min. Finally, it was calcined at 500° C. for 3 hours with a heating rate of 1° C./min to obtain a platinum-supported eggshell-type noble metal catalyst. Fig. 4 is a TEM photograph of the catalyst.

实施例8Example 8

称取0.1120g的H₂PtCl₆·6H₂O固体溶于19.8mL去离子水中，然后滴加0.2mL的氨水溶液，此时溶液的pH值为10左右；随后再将0.4g由实施例2制备的管状空心二氧化硅载体加到上述溶液中，静置浸渍12h后过滤，洗涤后于80℃下干燥。最后进行煅烧，先以2℃/min的速率程序升温至500℃，再在此温度下保持3h，即得到负载铂的管状蛋壳型催化剂。Weigh 0.1120g of H₂ PtCl₆ 6H₂ O solid and dissolve it in 19.8mL of deionized water, then add dropwise 0.2mL of ammonia solution, at this time the pH of the solution is about 10; The prepared tubular hollow silica carrier was added to the above solution, left to soak for 12 hours, filtered, washed and dried at 80°C. Finally, calcination is carried out, and the temperature is programmed to rise to 500° C. at a rate of 2° C./min, and then kept at this temperature for 3 hours to obtain a platinum-supported tubular eggshell catalyst.

实施例9Example 9

称取0.0446g的H₂PtCl₆·6H₂O固体溶于8mL去离子水中，得到所需的氯铂酸溶液。然后将此溶液缓慢滴入1.1g由实施例1制备的球状空心二氧化硅载体粉末里，刚好形成糊状且没有多余的液体出现。室温下放置1h后置于90℃下干燥10h，等水分挥发完后将获得的干粉在500℃下煅烧3h，其升温速率为2℃/min，即获得负载铂的蛋壳型贵金属催化剂。Weigh 0.0446 g of H₂ PtCl₆ ·6H₂ O solid and dissolve it in 8 mL of deionized water to obtain the desired chloroplatinic acid solution. Then slowly drop this solution into 1.1 g of the spherical hollow silica carrier powder prepared in Example 1, just to form a paste and no excess liquid appears. Place at room temperature for 1 hour and then dry at 90°C for 10 hours. After the water evaporates, the obtained dry powder is calcined at 500°C for 3 hours at a heating rate of 2°C/min to obtain a platinum-supported eggshell-type noble metal catalyst.

实施例10Example 10

称取0.99g Ni(NO₃)₂·6H₂O固体，用适量的去离子水溶解，得到硝酸镍溶液。将2g由实施例1制备的球状空心SiO₂载体加入到上述溶液中，搅拌浸渍负载12h，过滤后，于105℃下干燥，其升温速率为10℃/min，最后将干燥后的粉体进行高温焙烧，焙烧温度为400℃，其升温速率为1℃/min，最后得到以球状空心SiO₂为载体的负载镍的蛋壳型催化剂。图5是该催化剂的TEM照片。Weigh 0.99g Ni(NO₃ )₂ ·6H₂ O solid and dissolve it with an appropriate amount of deionized water to obtain a nickel nitrate solution. Add 2g of the spherical hollow_SiO2 carrier prepared in Example 1 into the above solution, stir and impregnate the load for 12h, filter and dry at 105°C with a heating rate of 10°C/min, and finally dry the dried powder High-temperature calcination, the calcination temperature is 400 °C, and the heating rate is 1 °C/min, and finally a nickel-loaded eggshell catalyst with spherical hollow_SiO2 as the carrier is obtained. Fig. 5 is a TEM photograph of the catalyst.

实施例11Example 11

称取0.1017g PdCl₂固体粉末，加入10mL去离子水和10mL 35％的浓盐酸，摇匀后进行加热溶解，加热至沸腾，直至溶液变得澄清、透明。再加入0.4955g的Ni(NO₃)₂·6H₂O加入到PdCl₂溶液中，搅拌，待其完全溶解、温度降至室温后，加入2 g由实施例1制备的球状空心SiO₂载体，搅拌浸渍负载12h，过滤后，于105℃下干燥，其升温速率为10℃/min，最后将干燥后的粉体进行高温焙烧，焙烧温度为450℃，其升温速率为1℃/min，煅烧时间为4h，最后得到以球状空心SiO₂为载体的负载镍-钯的蛋壳型催化剂。Weigh 0.1017g of PdCl₂ solid powder, add 10mL of deionized water and 10mL of 35% concentrated hydrochloric acid, shake well, heat to dissolve, and heat to boiling until the solution becomes clear and transparent. Then add 0.4955g of Ni(NO₃ )₂ 6H₂ O into the PdCl₂ solution, stir, and after it is completely dissolved and the temperature drops to room temperature, add 2 g of the spherical hollow SiO₂ carrier prepared in Example 1, Stir and impregnate the load for 12 hours, filter, and dry at 105°C with a heating rate of 10°C/min. Finally, the dried powder is calcined at a high temperature at 450°C with a heating rate of 1°C/min. The time is 4h, and finally the eggshell catalyst of supporting nickel-palladium with spherical hollow_SiO as the carrier is obtained.

实施例12Example 12

称取11.74g的Cu(NO₃)₂和11.63g的Zn(NO₃)₂，加入去离子水配制成混合溶液。再称取2g由实施例1制备的球状空心SiO₂载体，加入20mL的去粒子水配制成胶体，并将其转移至500mL的烧瓶内，搅拌，搅拌速度为500r/min。在室温下将硝酸铜和硝酸锌的混合溶液加入到SiO₂胶体中，同时滴加一定浓度的Na₂CO₃溶液，维持体系的pH值在9～10之间，反应时间为10h。待反应结束后，过虑，并用乙醇洗涤，于95℃下干燥8h，筛分，500℃下煅烧，煅烧时间为4h，即可得到球状空心SiO₂负载铜-锌的蛋壳型催化剂。11.74g of Cu(NO₃ )₂ and 11.63g of Zn(NO₃ )₂ were weighed, and deionized water was added to prepare a mixed solution. Then weigh 2g of the spherical hollow_SiO2 carrier prepared in Example 1, add 20mL of particle-free water to prepare a colloid, and transfer it to a 500mL flask, stir at a stirring speed of 500r/min. Add the mixed solution of copper nitrate and zinc nitrate to the SiO₂ colloid at room temperature, and at the same time add a certain concentration of Na₂ CO₃ solution dropwise to maintain the pH value of the system between 9 and 10, and the reaction time is 10h. After the reaction is finished, filter, wash with ethanol, dry at 95°C for 8 hours, sieve, and calcinate at 500°C for 4 hours to obtain a spherical hollow SiO₂ supported copper-zinc eggshell catalyst.

实施例13Example 13

称取0.5g由实施例3制备的负载PdO的蛋壳型贵金属催化剂，将其装填于容积为5mL、内径为10mm的微型固定床反应器中，采用纯度为99.999％的高纯氢进行氢气还原，还原时采用程序升温，升温速率为2℃/min，还原温度为400℃，氢气流量为30mL/min，还原时间为3h，即可得到经预处理的蛋壳型贵金属钯催化剂。还原结束后，将温度降至220℃，通入合成气进行CO加氢反应，合成气中H₂与CO的体积比为2∶1，流量为60mL/min，同时调整反应压力至2MPa，采用气相色谱对反应产物进行在线分析，产物分析表明，采用以球状空心SiO₂载体负载贵金属Pd的CO加氢制甲醇的选择性达到100％，CO的单程转化率达到8％，说明采用空心SiO₂载体负载金属制备的蛋壳型贵金属催化剂能够使得CO加氢反应，其单程转化率和采用一般硅胶为载体制备的贵金属催化剂的转化率相当，但是甲醇的选择性相对较高。Weigh 0.5g of the PdO-loaded eggshell-type noble metal catalyst prepared in Example 3, fill it in a miniature fixed-bed reactor with a volume of 5mL and an inner diameter of 10mm, and use high-purity hydrogen with a purity of 99.999% for hydrogen reduction. When using temperature programming, the heating rate is 2°C/min, the reduction temperature is 400°C, the hydrogen flow rate is 30mL/min, and the reduction time is 3h, the pretreated eggshell-type precious metal palladium catalyst can be obtained. After the reduction, the temperature was lowered to 220°C, and the synthesis gas was fed to carry out CO hydrogenation reaction. The volume ratio of_H2 and CO in the synthesis gas was 2:1, and the flow rate was 60mL/min. At the same time, the reaction pressure was adjusted to 2MPa, using The reaction product was analyzed online by gas chromatography. The product analysis showed that the selectivity of CO hydrogenation to methanol with spherical hollow SiO₂ carrier loaded with noble metal Pd reached 100%, and the single-pass conversion rate of CO reached 8%, indicating that the use of hollow SiO₂ The eggshell-type noble metal catalyst prepared by supporting metal on the carrier can make CO hydrogenation reaction, and its single-pass conversion rate is equivalent to that of the noble metal catalyst prepared by using ordinary silica gel as the carrier, but the selectivity of methanol is relatively high.

实施例14Example 14

称取0.5g由实施例4制备的负载PdO的以碱土金属Ca为助催化剂的蛋壳型贵金属催化剂，将其装填于容积为5mL、内径为10mm的微型固定床反应器中，采用纯度为99.999％的高纯氢进行氢气还原，还原时采用程序升温，升温速率为2℃/min，还原温度为400℃，氢气流量为30mL/min，还原时间为3h，即可得到经预处理的以碱土金属Ca为助催化剂的蛋壳型贵金属钯催化剂Ca-Pd/SiO₂。还原结束后，将温度降至220℃，通入合成气进行CO加氢反应，合成气中H₂与CO的体积比为2∶1，流量为60mL/min，同时调整反应压力至2MPa，采用气相色谱对反应产物进行在线分析，产物分析表明，采用以空心SiO₂载体以Ca为助催化剂的贵金属Pd催化剂的CO加氢反应制甲醇的选择性达到100％，CO的单程转化率达到15％，说明以球状空心SiO₂为载体，碱土金属Ca为助催化剂的蛋壳型贵金属钯催化剂能够使得CO加氢反应的单程转化率较高，比采用一般硅胶为载体制备的贵金属催化剂的转化率高，同时甲醇的选择性相对较高。Weigh 0.5g of the eggshell-type noble metal catalyst with alkaline earth metal Ca as the promoter of the loaded PdO prepared in Example 4, and fill it in a miniature fixed-bed reactor with a volume of 5mL and an inner diameter of 10mm, using a purity of 99.999 % high-purity hydrogen for hydrogen reduction, using temperature programming during reduction, the heating rate is 2°C/min, the reduction temperature is 400°C, the hydrogen flow rate is 30mL/min, and the reduction time is 3h, the pretreated alkaline earth metal Ca can be obtained. Eggshell type noble metal palladium catalyst Ca-Pd/SiO₂ as co-catalyst. After the reduction, the temperature was lowered to 220°C, and the synthesis gas was fed to carry out CO hydrogenation reaction. The volume ratio of_H2 and CO in the synthesis gas was 2:1, and the flow rate was 60mL/min. At the same time, the reaction pressure was adjusted to 2MPa, using The reaction products were analyzed online by gas chromatography, and the product analysis showed that the selectivity of CO hydrogenation reaction to methanol using the noble metal Pd catalyst with hollow_SiO2 carrier and Ca as the cocatalyst reached 100%, and the single-pass conversion rate of CO reached 15% , indicating that the spherical hollow SiO₂ is used as the carrier, and the eggshell-type noble metal palladium catalyst of the alkaline earth metal Ca as the promoter can make the single-pass conversion rate of the CO hydrogenation reaction higher, which is higher than that of the noble metal catalyst prepared by using ordinary silica gel as the carrier. , while the selectivity of methanol is relatively high.

实施例15Example 15

称取0.3g由实施例11制备的负载镍-钯蛋壳型催化剂，将其装填于容积为5mL、内径为10mm的微型固定床反应器中，采用纯度为99.999％的高纯氢进行氢气还原，还原时采用程序升温，升温速率为2℃/min，还原温度为400℃，氢气流量为30mL/min，还原时间为3h，即可得到经预处理的Ni-Pd/SiO₂催化剂。还原结束后，将温度降至220℃，通入合成气进行CO加氢反应，合成气中H₂与CO的体积比为2∶1，流量为60mL/min，同时调整反应压力至2MPa，采用气相色谱对反应产物进行在线分析，产物分析表明，采用以空心SiO₂载体的Ni-Pd催化剂，其CO加氢反应制甲醇的选择性达到100％，CO的单程转化率达到7％。Weigh 0.3 g of the supported nickel-palladium eggshell catalyst prepared in Example 11, fill it in a miniature fixed-bed reactor with a volume of 5 mL and an inner diameter of 10 mm, and use high-purity hydrogen with a purity of 99.999% to carry out hydrogen reduction. When using a temperature program, the heating rate is 2°C/min, the reduction temperature is 400°C, the hydrogen flow rate is 30mL/min, and the reduction time is 3h, the pretreated Ni-Pd/SiO₂ catalyst can be obtained. After the reduction, the temperature was lowered to 220°C, and the synthesis gas was fed to carry out CO hydrogenation reaction. The volume ratio of_H2 and CO in the synthesis gas was 2:1, and the flow rate was 60mL/min. At the same time, the reaction pressure was adjusted to 2MPa, using The reaction product was analyzed online by gas chromatography. The product analysis showed that_the selectivity of CO hydrogenation reaction to methanol reached 100%, and the single-pass conversion rate of CO reached 7%.

实施例16Example 16

称取0.3g由实施例10制备的负载型镍催化剂，装填于容积为5mL、内径为10mm的微型固定床反应器中，采用纯度为99.999％的高纯氢进行氢气还原，还原时采用程序升温，升温速率为2℃/min，还原温度为400℃，氢气流量为30mL/min，还原时间为3h。还原结束后，将温度降至220℃，通入合成气(H₂与CO的体积比为2∶1)，其流量为60mL/min，同时调整反应压力至2MPa。采用气相色谱对反应产物进行在线分析。产物分析表明，采用以空心SiO₂载体负载金属镍在CO加氢制甲醇的选择性达到100％，CO的单程转化率达到68％，说明采用空心SiO₂载体负载金属制备的蛋壳型催化剂能够使得CO加氢反应的单程转化率较高。CO的单程转化率和甲醇的选择性随着反应时间的变化如图6所示。Weigh 0.3g of the loaded nickel catalyst prepared by Example 10, fill it in a miniature fixed-bed reactor with a volume of 5mL and an internal diameter of 10mm, and use high-purity hydrogen with a purity of 99.999% to carry out hydrogen reduction. The rate is 2°C/min, the reduction temperature is 400°C, the hydrogen flow rate is 30mL/min, and the reduction time is 3h. After the reduction, the temperature was lowered to 220 ° C, and the synthesis gas (the volume ratio of_H2 and CO was 2:1) was introduced at a flow rate of 60 mL/min, while the reaction pressure was adjusted to 2 MPa. The reaction products were analyzed online by gas chromatography. The product analysis shows that the selectivity of CO hydrogenation to methanol by using metal nickel supported on hollow_SiO2 carrier reaches 100%, and the single-pass conversion rate of CO reaches 68%, which shows that the eggshell catalyst prepared by using hollow_SiO2 carrier to load metal can The single-pass conversion rate of CO hydrogenation reaction is higher. The one-pass conversion of CO and the selectivity of methanol as a function of reaction time are shown in Fig. 6.

Claims (10)

1. an egg shell type metal catalyst is made up of silica supports, noble metal and/or transition metal, selectable base metal co-catalyst, it is characterized in that wherein said carrier is the silica of hollow-core construction.

2. catalyst according to claim 1, it is characterized in that, with catalyst weight percentage is that the composition of benchmark comprises: 0.1%～5.0% noble metal and/or 5.0%～40.0% transition metal, 0～0.5% base metal co-catalyst, 60.0%～99.0% hollow silicon dioxide carrier.

3. catalyst according to claim 1 is characterized in that, wherein said carrier is spherical or tubulose, and the specific area of spherical hollow silicon dioxide particle is 500～1500m²/ g, pore volume are 0.3～1.0mL/g; Tubular, hollow SiO₂The specific area of particle is 400～1000m²/ g, pore volume are 0.3～1.0mL/g, and diameter is 80～150nm, and length is 1～3 μ m.

4. catalyst according to claim 3 is characterized in that, the specific area of wherein said spherical hollow silicon dioxide particle is 500～1000m²/ g, pore volume are 0.5～0.9mL/g; Tubular, hollow SiO₂The specific area of particle is 500～800m²/ g, pore volume are 0.5～0.8mL/g.

5. catalyst according to claim 1, it is characterized in that, wherein said noble metal is selected from one or more among Pd, Pt, the Rh, described transition metal is selected from one or more among Ni, Cu, the Zn, and described base metal co-catalyst is selected from one or more in alkali metal, alkaline-earth metal, group vib element and other transition metal.

6. the preparation method of an egg shell type metal catalyst is characterized in that, this method in turn includes the following steps:

The hollow silicon dioxide carrier is joined in acetate, nitrate, sulfate or the halid solution of at least a noble metal and/or at least a transition metal, and fully mix with it, temperature is controlled at 20～80 ℃; Load is filtered after finishing, and is warmed up to 80～130 ℃ with 10～20 ℃/min, dry 3～15h; With dried powder screening, be warmed up to 400～500 ℃ with 1～5 ℃/min at last, calcining 3～12h.

7. the preparation method of an egg shell type metal catalyst is characterized in that, this method in turn includes the following steps:

Adopt polymethyl methacrylate to make organic formwork, ethyl orthosilicate is the silicon source, the acetate of at least a noble metal and/or at least a transition metal, nitrate, sulfate or halide are presoma, with the corresponding acid of halide or salt be hydrolytic reagent and precipitating reagent, control pH value is between 1～3, and hydrolysis 10～20h is to the solution clear; Filter, be warmed up to 95～115 ℃ with 10～20 ℃/min then, dry 5～10h; With dried powder screening, be warmed up to 400～600 ℃ with 1～5 ℃/min at last, calcining 3～7h.

8. the preparation method of an egg shell type metal catalyst is characterized in that, this method in turn includes the following steps:

Acetate, nitrate, sulfate or the halid solution of transition metal are joined hollow SiO₂In the colloidal solution of carrier, and fully stir with it, drip simultaneously and be selected from Na₂CO₃, NaCHO₃Perhaps NH₃HCO₃Precipitating reagent, mixing speed is controlled at 400～600r/min, the pH value of maintenance system is between 8～10, mixing time is 12～24h; Load is filtered after finishing, and is warmed up to 90～110 ℃ with 10～20 ℃/min then, dry 3～12h; Dried powder sieves with standard screen, and the powder after the screening is carried out calcination processing, and calcining heat is 450～500 ℃, and heating rate is 1～5 ℃/min, and calcination time is 3～10h.

9. the preparation method of an egg shell type metal catalyst is characterized in that, this method in turn includes the following steps:

To further join in the solution of non-noble metal halide, nitrate or carbonate according to claim 6 or 7 or 8 catalyst that make, and fully mix with it, temperature is controlled at 20～80 ℃; Load is filtered after finishing, and is warmed up to 90～110 ℃ with 10～20 ℃/min, dry 3～12h; With dried powder screening, be warmed up to 400～450 ℃ with 1～5 ℃/min at last, calcining 3～10h.

10. the application of the catalyst of each of claim 1～5 in co hydrogenation system methyl alcohol.

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