CN112194577A - Method for preparing cyclopentanone compounds from furfural and furfural derivatives through aqueous phase hydrogenation rearrangement - Google Patents

Abstract

Translated fromChinese

本发明提供一种糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，属于生物质资源催化转化领域。具体的，负载型Ni₃P催化剂在H₂气氛中，将糠醛及其衍生物转化为环戊酮类化合物；本发明的负载型Ni₃P催化剂通过沉积沉淀‑化学镀的方法制备得到。本发明方法得到的催化剂分散度高，颗粒尺寸小。该催化剂在糠醛及其衍生物水相加氢重排制备环戊酮及其衍生物的反应中具有较高的糠醛及其衍生物转化率和环戊酮类化合物选择性。本发明在4MPa H₂，160℃，反应1h后，糠醛转化率和环戊酮选择性分别达到89.1％和81.3％。

The invention provides a method for preparing cyclopentanone compounds by hydrogenation and rearrangement of furfural and its derivatives in water, belonging to the field of catalytic conversion of biomass resources. Specifically, the supported Ni₃ P catalyst converts furfural and its derivatives into cyclopentanone compounds in an H₂ atmosphere; the supported Ni₃ P catalyst of the present invention is prepared by a deposition precipitation-electroless plating method. The catalyst obtained by the method of the present invention has high dispersity and small particle size. The catalyst has higher conversion rate of furfural and its derivatives and selectivity of cyclopentanone compounds in the reaction of furfural and its derivatives in the water-phase hydrogenation rearrangement to prepare cyclopentanone and its derivatives. In the present invention, the conversion rate of furfural and the selectivity of cyclopentanone reach 89.1% and 81.3% respectively after the reaction at 4MPa H₂ and 160° C. for 1 h.

Description

Method for preparing cyclopentanone compounds from furfural and furfural derivatives through aqueous phase hydrogenation rearrangement

Technical Field

The invention belongs to the technical field of catalytic chemical industry, and particularly discloses a method for preparing cyclopentanone compounds by aqueous phase hydrogenation rearrangement by taking furfural and derivatives thereof as raw materials.

Technical Field

Furfural is produced from renewable agricultural resources such as corncobs, bagasse, cottonseed hulls, wood waste and the like through acidolysis, and is an important chemical raw material synthesized by using renewable biomass resources through reaction. Furfural is active in chemical properties, is considered to be one of the most promising platform compounds extracted directly from biomass, and can be used for preparing various intermediate products such as: cyclopentanone, cyclopentanol, furfuryl alcohol, 2-methylfuran, tetrahydrofurfuryl alcohol, etc., and are widely used in the industries of synthetic plastics, medicines, pesticides, etc.

Cyclopentanone is an important fine chemical intermediate, and can be used for preparing the anxiolytic buspirone and the like in the field of medicine; methyl jasmonate prepared from cyclopentanone in agriculture can play a hormone-like role and plays a role in influencing the secondary metabolism of plants as a signal substance in plants; in the aspect of perfume, cyclopentanone can be used for synthesizing methyl dihydrojasmonate, and the methyl dihydrojasmonate has aromatic and lasting fragrance and is widely applied to the preparation of high-grade perfume and cosmetic essence.

The main synthesis process of cyclopentanone is currently pyrolysis of adipic acid and its derivatives. Mixing adipic acid powder with barium hydroxide catalyst, and heating and distilling to prepare cyclopentanone. Patent CN1594259 adopts a catalytic reaction tower and takes adipic acid as raw material in Ni-Cu/Al₂O₃Preparing cyclopentanone and cyclopentanol under the condition of catalyst, the method improves the yield of cyclopentanone by reducing the generation of high boiling point substance by further self-polymerization reaction of cyclopentanone in the production process, and 1460Kg of adipic acid is added807Kg of cyclopentanone was obtained with a yield of 96%.

Another technical route for preparing cyclopentanone is the cyclopentene oxidation method, Dubkvo et al (React. Kinet. Catal. Lett., 2002, 77: 197-₂And (3) producing cyclopentanone by an O selective liquid-phase oxidation method. Oxidant N₂When the O is directly contacted with the liquid cyclopentene at high temperature, the O can directly interact with a C ═ C double bond of a hydrocarbon, and an oxygen atom of the hydrocarbon is transferred to an unsaturated carbon atom, so that the selectivity of 100 percent cyclopentanone can be almost achieved.

The method for preparing cyclopentanone based on the traditional method has the problems of high price of raw materials, great environmental pollution, high requirements on production equipment and the like, in recent years, petroleum resources are gradually exhausted, and a new method for preparing cyclopentanone by using a biomass platform compound furfural as a raw material is provided. The process for preparing cyclopentanone through furfural aqueous phase hydrogenation rearrangement adopts renewable biomass platform compound furfural as a raw material, replaces traditional fossil energy sources such as adipic acid and cyclopentene, solves the consumption problem of the fossil energy sources, meets the market demand of cyclopentanone, and can effectively improve the utilization rate of biomass resources. Therefore, the method is a new route which accords with sustainable development and has follow-up research significance.

The patent CN110041168 synthesizes 10 percent Co-10 percent Ni/TiO by an excess impregnation method₂The method for preparing cyclopentanone by catalyzing furfural aqueous phase hydrogenation rearrangement through a bimetallic catalyst at 6MPaH₂And the reaction is carried out for 4 hours at 140 ℃, so that 100 percent of furfural conversion rate and 51 percent of cyclopentanone selectivity can be achieved. Patent CN103111299 adopts a double-dropping coprecipitation method to prepare a high-loading activated carbon nanotube-loaded copper, nickel, cobalt and magnesium catalyst, and applies the high-loading activated carbon nanotube-loaded copper, nickel, cobalt and magnesium catalyst to furfural aqueous phase hydrogenation reaction to obtain high-yield cyclopentanone. The prior method has the technical problems of complex catalyst preparation, harsh reaction conditions or low cyclopentanone selectivity.

Disclosure of Invention

The invention aims to provide a novel method for preparing cyclopentanone compounds by efficiently catalyzing furfural and furfural derivatives through aqueous phase hydrogenation rearrangementThe method is independent of fossil resources, takes renewable biomass resources furfural and derivatives thereof as raw materials and carries Ni₃Preparing cyclopentanone compounds under the action of the P catalyst. The method is a new route which accords with sustainable development and has follow-up research significance and industrial prospect.

The technical scheme of the invention is as follows:

a method for preparing cyclopentanone compounds by catalyzing furfural and derivatives thereof through aqueous phase hydrogenation rearrangement comprises the steps of taking furfural and derivatives thereof as raw materials, taking water as a solvent and loading Ni₃P catalyst in H₂In the atmosphere, furfural and derivatives thereof are converted into cyclopentanone compounds through aqueous phase hydrogenation rearrangement; the supported Ni₃The active component in the P catalyst is Ni₃P, the carrier is one of oxide, molecular sieve, active carbon and rare earth phosphate; the loading of Ni is 5-35 wt.%.

Preferably said Ni₃The particle size of P is 3-6 nm.

Preferably, the carrier is gamma-Al₂O₃、TiO₂Al-SBA-15, Al-MCM-41, activated carbon and CePO₄One kind of (1).

Preferably, in the reaction system, the concentration of the furfural aqueous solution is 0.5-8 wt.%, and the supported Ni is₃The dosage of the P catalyst is 10-50% of the mass of the furfural, the reaction temperature is 100-200 ℃, the pressure of reaction hydrogen is 0.1-4MPa, the reaction time is 0.5-12h, and the stirring speed is 500-1000 rpm. Further, the reaction temperature is 140-180 ℃; the reaction hydrogen is 2-4 MPa; the reaction time is 1-4 h; the concentration of the furfural aqueous solution is 5 percent; the dosage of the catalyst is 20 percent of the mass of the furfural.

Preferably the supported Ni₃The P catalyst is prepared by a method combining deposition precipitation and chemical plating, the method is low in cost, and the obtained supported Ni₃The P catalyst has high activity for catalyzing furfural aqueous phase hydrogenation rearrangement to prepare cyclopentanone.

Further, the supported Ni₃The preparation method of the P catalyst specifically comprises the following steps:

s1, weighing Ni (NO)₃)₂·6H₂Dissolving O in deionized water to form Ni (NO)₃)₂Aqueous solution, Ni (NO)₃)₂The concentration range of the aqueous solution is 0.004-0.04 mol/L; taking part of the Ni (NO)₃)₂Adding a carrier into the aqueous solution, and heating the aqueous solution under stirring to form a suspension; weighing urea to add to the rest of the Ni (NO)₃)₂Adding concentrated nitric acid into the aqueous solution to form a mixed solution, wherein the amount of urea substances in the mixed solution is 0.1-0.5mol, and the pH value of the solution is 1-2; dropwise adding the obtained mixed solution into the turbid solution, heating to 90-95 ℃ after the dripping is finished, and reacting for 1-24 h; after the reaction is finished, carrying out suction filtration, washing until the filtrate is neutral, and drying to obtain a precursor compound;

s2, preparing an acetic acid-sodium acetate buffer solution with pH of 4-6.5, adding NaH₂PO₂In which NaH₂PO₂The concentration of the precursor compound is 0.04-2.5mol/L, the temperature is raised to 80-95 ℃ under stirring, the precursor compound obtained from S1 is added, after the reaction is finished, the filtration is carried out, the washing is carried out until the filtrate is neutral, the drying is carried out, and the reaction is carried out in H₂Carrying out heat treatment at 350-500 ℃ for 1-5h in the atmosphere, and then cooling and annealing to obtain the high-dispersion supported Ni₃And (3) a P catalyst.

The invention has the advantages of simple reaction process, mild conditions and supported Ni₃Active component Ni of P catalyst₃P has higher hydrogenation active center and stably exists in water phase, and meanwhile, the carrier provides weak L acid center, Ni₃The P is matched with the carrier, so that the conversion rate of the furfural and the derivatives thereof and the selectivity of cyclopentanone compounds are improved; in addition, the invention adopts a method of combining a deposition precipitation method and a chemical plating method to prepare the supported Ni₃The P catalyst obviously improves the dispersity and prepares nano-grade supported Ni₃The P catalyst has the particle size of 3-6nm and can further catalyze furfural and derivatives thereof to convert to prepare cyclopentanone compounds with high selectivity; in particular, Ni of the invention₃P and gamma-Al₂O₃The mutual synergistic action of carriers, the conversion rate of furfural and derivatives thereof and the selectivity of cyclopentanone compounds are obviousRemarkably improved at 4MPa H₂And at 160 ℃, after the reaction is carried out for 1h, the furfural conversion rate and the cyclopentanone selectivity respectively reach 89.1 percent and 81.3 percent.

Drawings

FIG. 1 shows different carriers loaded with Ni₃XRD spectrum of P catalyst.

Detailed Description

The present invention is further illustrated by the following specific examples, which should be understood by those skilled in the art, but not limited thereto.

Example 1

Preparing precursor by deposition precipitation method and preparing Ni by chemical plating method₃P/γ-Al₂O₃A catalyst.

2.62g of Ni (NO)₃)₂·6H₂Dissolving O in deionized water to obtain Ni (NO)₃)₂Solution 4/5 to which was added 2.4g of gamma-Al₂O₃Heating the carrier to 70 ℃ under continuous stirring to form a suspension; 7.56g of urea are weighed out and added to the remaining Ni (NO)₃)₂And adding 0.56g of concentrated nitric acid into the solution to form a mixed solution, dropwise adding the mixed solution into the suspension at 70 ℃, heating to 90 ℃ after dropwise adding, and reacting for 16 hours. After the reaction is finished, carrying out suction filtration, washing until the filtrate is neutral, and drying for 12h to obtain a precursor compound; then 100mL of acetic acid-sodium acetate buffer solution with pH of 5.5 is prepared, and 9.55g of NaH is added₂PO₂Continuously stirring and heating to 90 ℃, and adding a precursor compound; after reacting for two hours, filtering, washing until the filtrate is neutral, drying for 12 hours, and H₂Heat treatment is carried out for 2h at 400 ℃ in the atmosphere, then cooling annealing is carried out, and Ni is obtained₃P/γ-Al₂O₃Catalyst, Ni loading 14% wt.%, particle size 3.8nm, XRD spectrum see figure 1.

Example 2

gamma-Al in example 1₂O₃Respectively changing the carrier into TiO₂Al-SBA-15, Al-MCM-41, activated carbon and CePO₄Obtaining Ni₃P/TiO₂、Ni₃P/Al-SBA-15、Ni₃P/Al-MCM-41、Ni₃P/AC and Ni₃P/CePO₄，Ni₃P/TiO₂And Ni₃P/CePO₄The XRD pattern of the catalyst is shown in figure 1.

The catalysts obtained in example 2 are respectively subjected to a reaction for preparing cyclopentanone by catalyzing furfural aqueous phase hydrogenation rearrangement.

The reaction steps are as follows: will carry Ni₃Adding the P catalyst, furfural and water into a high-pressure reaction kettle, sealing the high-pressure reaction kettle, replacing air in the kettle, filling hydrogen, starting reaction, quickly cooling the reaction kettle after the reaction is finished, and performing chromatographic analysis by adopting an internal standard method after centrifugal treatment. The internal standard substance is 1, 4-dioxane. The analysis was carried out in an Aglient 6890N gas chromatograph on a commercially available HP-Innowax capillary column, hydrogen flame detector.

Reaction conditions are as follows: 0.2g of supported Ni₃P catalyst, 20g of 5% aqueous furfural solution, 4MPaH₂And reacting at 160 ℃ for 1 h. The reaction results are shown in Table 1.

From the experimental results in table 1, Ni can be preferably selected by comprehensively considering the furfural conversion rate and the target product cyclopentanone selectivity₃P/γ-Al₂O₃The catalyst was subjected to subsequent experimental studies.

TABLE 1 Synthesis of Ni Supported on different Carriers by precipitation-electroless plating₃Reaction results of the P catalyst.

Example 3

Ni of the above example 1₃P/γ-Al₂O₃Experimental results of the catalysts at different reaction times.

Reaction conditions are as follows: 0.2g of catalyst, 20g of 5% aqueous furfural solution, 4MPaH₂And reacting at 180 ℃ for different times. The reaction results are shown in Table 2. From the experimental results of table 2, the cyclopentanone selectivity increased first and then decreased with increasing reaction time.

TABLE 2 Ni₃P/γ-Al₂O₃Reaction results of different reaction times of the catalyst.

Reaction time (h)	Furfural conversion (%)	Cyclopentanone selectivity (%)
			0.5	78.0	75.0
1	98.9	76.1
			2	99.5	53.2
4	99.9	24.9

Example 4

Ni of the above example 1₃P/γ-Al₂O₃The catalyst was reacted at different temperatures for 1 h.

Reaction conditions are as follows: 0.2g of catalyst, 20g of 5% aqueous furfural solution, 4MPaH₂The reaction was carried out for 1h at different temperatures. The reaction results are shown in Table 3. From the experimental results of Table 3, the furfural conversion rate was continuously increased with the increase of the reaction temperatureHigh, but cyclopentanone selectivity increased first and then decreased, reaching a maximum at 160 ℃.

TABLE 3 Ni₃P/Al₂O₃The reaction results of different reaction temperatures of the catalyst.

Reaction temperature (. degree.C.)	Furfural conversion (%)	Cyclopentanone selectivity (%)
			140	61.5	52.1
160	89.1	81.3
			180	98.9	76.1
200	98.2	68.6

Example 5

Ni of the above example 1₃P/γ-Al₂O₃The catalyst reacts under different pressures for 1h and at 160 ℃.

Reaction conditions are as follows: 0.2g of catalyst, 20g of 5% furfural water solution, and reacting at 160 ℃ and different pressures for 1 hour. The reaction results are shown in Table 4. From the experimental results in table 4, too low hydrogen pressure fails to cause bond-breaking rearrangement of furfuryl alcohol, which is a reaction intermediate, resulting in reduced cyclopentanone selectivity, similar selectivity between cyclopentanone at 2MPa and cyclopentanone at 4MPa, but furfural at 4MPa has higher conversion rate, and further increasing pressure results in excessive hydrogenation of cyclopentanone to cyclopentanol.

TABLE 4 Ni₃P/γ-Al₂O₃The reaction results of different reaction pressures of the catalyst.

Reaction pressure (MPa)	Furfural conversion (%)	Cyclopentanone selectivity (%)
			1	27.6	66.1
2	60.8	81.7
			4	89.1	81.3

Example 6

Ni of the above example 1₃P/γ-Al₂O₃The catalyst catalyzes 5-hydroxymethylfurfural or 5-methylfurfural to react.

Reaction conditions are as follows: 0.2g Ni₃P/γ-Al₂O₃Catalysis20g of 5% aqueous solution of 5-hydroxymethylfurfural or 5-methylfurfural at 160 ℃ in 4MPaH₂And reacting for 1 h. The reaction results are shown in Table 5. From the experimental results in Table 5, it was found that cyclopentanone compounds were produced in the case of 5-hydroxymethylfurfural or 5-methylfurfural as the starting material, and that synthesized Ni₃P/γ-Al₂O₃The catalyst is generally suitable for hydrogenation rearrangement reaction of furfural and derivatives thereof to prepare cyclopentanone compounds.

TABLE 5 Ni₃P/γ-Al₂O₃The catalyst catalyzes the reaction result of 5-hydroxymethylfurfural or 5-methylfurfural.

Comparative examples

Bulk Ni prepared by coprecipitation₃P,Co₂And catalyzing furfural hydrogenation rearrangement by using P and MoP catalysts to prepare cyclopentanone.

Mixing 8.72g of Ni (NO)₃)₂·6H₂Dissolving O in deionized water to obtain Ni (NO)₃)₂Solution, 1.32g (NH)₄)₂·HPO₄Dissolving in deionized water, adding (NH)₄)₂·HPO₄Solution addition of Ni (NO)₃)₂Stirring the solution for 30min, quickly evaporating water to dryness, drying for 12h, roasting at 500 ℃ for 3h to obtain a catalyst precursor, reducing the precursor in a hydrogen atmosphere at 500 ℃ for 2h, and then using 5% O₂/Ar₂Passivating to obtain Ni₃And (3) a P catalyst.

Co can be prepared by the same method₂P catalyst (molar ratio Co: P ═ 2) and MoP catalyst (molar ratio Mo: P ═ 1).

Reaction conditions are as follows: 0.2g of catalyst, 20g of 5% furfural aqueous solution, 180 ℃ 4MPaH₂And reacting for 1 h. The reaction results are shown in Table 6. From the results of the experiments in table 6,

TABLE 6 Ni₃P catalyst, Co₂P catalyst, MoP catalyst and example 1Ni₃P/γAl₂O₃Comparison of reaction results

Catalyst and process for preparing same	Furfural conversion (%)	Cyclopentanone selectivity (%)
			Ni3P	99.9	50.8
Co2P	59.5	44.5
			MoP	61.1	17.8
Ni3P/γAl2O3	98.9	76.1

Claims (6)

Translated fromChinese

1.一种糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于，负载型Ni₃P催化剂在H₂气氛中，将糠醛及其衍生物转化为环戊酮类化合物；所述负载型Ni₃P催化剂中的活性组分为Ni₃P，载体为氧化物、分子筛、活性炭和稀土磷酸盐中的一种；Ni的负载量是5-35wt.％。1. a method for preparing cyclopentanone compounds by_{hydrogenation} and rearrangement of furfural and its derivative in water, it is characterized in that, the supported Ni₃ P catalyst is in H atmosphere, and furfural and its derivative are converted into cyclopentanone Ketone compounds; the active component in the supported Ni₃ P catalyst is Ni₃ P, the carrier is one of oxides, molecular sieves, activated carbon and rare earth phosphate; the loading of Ni is 5-35wt.%.2.如权利要求1所述的糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于，Ni₃P的颗粒尺寸为3-6nm。2 . The method for preparing cyclopentanone compounds by aqueous hydrogenation rearrangement of furfural and its derivatives according to claim 1 , wherein the particle size of Ni₃ P is 3-6 nm. 3 .3.如权利要求1所述的糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于，所述载体为γ-Al₂O₃、TiO₂、Al-SBA-15、Al-MCM-41、活性炭和CePO₄中的一种。3. The method for preparing cyclopentanone compounds by water-phase hydrogenation rearrangement of furfural and its derivatives as claimed in claim 1, wherein the carrier is γ-Al₂ O₃ , TiO₂ , Al-SBA One of -15, Al-MCM-41, activated carbon and CePO₄ .4.如权利要求1所述的糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于，在反应体系中，糠醛水溶液浓度为0.5-8wt.％，所述负载型Ni₃P催化剂用量为糠醛质量的10-50％，反应温度为100-200℃，反应氢气压力0.1-4MPa，反应时间为0.5-12h，搅拌速度为500-1000rpm。4. the method for preparing cyclopentanone compound by furfural and its derivative water-phase hydrogenation rearrangement as claimed in claim 1, is characterized in that, in reaction system, furfural aqueous solution concentration is 0.5-8wt.%, described The amount of the supported Ni₃ P catalyst is 10-50% of the mass of furfural, the reaction temperature is 100-200° C., the reaction hydrogen pressure is 0.1-4MPa, the reaction time is 0.5-12h, and the stirring speed is 500-1000rpm.5.如权利要求1或2所述的糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于：所述负载型Ni₃P催化剂通过沉积沉淀和化学镀相结合的方法制备得到。5. the method for preparing cyclopentanone compounds by the hydrogenation rearrangement of furfural and its derivatives in water as claimed in claim 1 or 2, it is characterized in that: described supported Ni₃ P catalyst is by deposition precipitation and electroless plating phase prepared by the combined method.6.如权利要求5所述的糠醛及其衍生物水相加氢重排制备环戊酮类化合物的方法，其特征在于：所述负载型Ni₃P催化剂的制备方法，具体包括如下步骤：6. the method for preparing cyclopentanone compounds by the aqueous hydrogenation rearrangement of furfural and derivatives thereof as claimed in claim 5, it is characterized in that: the preparation method of described supported Ni₃ P catalyst, specifically comprises the steps:S1、称取Ni(NO₃)₂·6H₂O溶于去离子水中，形成Ni(NO₃)₂水溶液，Ni(NO₃)₂水溶液的浓度范围为0.004-0.04mol/L；取部分所述Ni(NO₃)₂水溶液，加入载体，搅拌下加热形成悬浊液；称取尿素加入到剩余所述Ni(NO₃)₂水溶液中，再加入浓硝酸，形成混合液，混合液中尿素的物质的量为0.1-0.5mol，溶液pH为1-2；将所得混合液逐滴加入到混浊液中，滴完升温至90-95℃，反应1-24h；反应完毕后，抽滤，洗涤至滤液呈中性，干燥，制得前体化合物；S1. Weigh Ni(NO₃ )₂ ·6H₂ O and dissolve it in deionized water to form a Ni(NO₃ )₂ aqueous solution. The concentration range of the Ni(NO₃ )₂ aqueous solution is 0.004-0.04mol/L; Described Ni(NO₃ )₂ aqueous solution, add carrier, heat under stirring to form a suspension; weigh urea and add it to the remaining described Ni(NO₃ )₂ aqueous solution, then add concentrated nitric acid to form a mixed solution, and the urea in the mixed solution The amount of the substance is 0.1-0.5mol, and the pH of the solution is 1-2; the obtained mixed solution is added dropwise to the turbid solution, and the temperature is raised to 90-95°C after dropping, and the reaction is performed for 1-24h; after the reaction is completed, suction filtration, Wash until the filtrate is neutral, and dry to obtain the precursor compound;S2、配制pH为4-6.5的乙酸-乙酸钠缓冲溶液，加入NaH₂PO₂，其中NaH₂PO₂的浓度范围0.04-2.5mol/L，搅拌下升温至80-95℃，加入S1所得前体化合物，待反应完毕后，经抽滤，洗涤至滤液呈中性，干燥，于H₂气氛下350-500℃热处理1-5h后降温退火，得到高分散的负载型Ni₃P催化剂。S2, prepare an acetic acid-sodium acetate buffer solution with a pH of 4-6.5, add NaH₂ PO₂ , wherein the concentration range of NaH₂ PO₂ is 0.04-2.5 mol/L, and heat up to 80-95° C. under stirring, before adding S1 to obtain After the reaction is completed, the filtrate is filtered by suction, washed until the filtrate is neutral, dried, heat-treated at 350-500 °C for 1-5 h under H₂ atmosphere, then cooled and annealed to obtain a highly dispersed supported Ni₃ P catalyst.

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