supported metal catalyst with synergistic sites, a preparation method therefor and an application thereof

Abstract

The present invention provides a supported metal catalyst with synergistic sites, a preparation method therefor and an application thereof. The preparation method of this catalyst is to utilize the unsaturated cubane-like structure, M cation with catalytic activity is introduced into the cluster core unit. By using the vertex vacancy as the capturing center, and adjusting the impregnation temperature to maximize the loading of the cluster precursor, as well as depending on the electrostatic adsorption of the support and the confinement of the cluster structural unit, the number of S vacancies and the distance between S vacancies and Miso sites are effectively controlled through liquid phase reduction and atmosphere treatment at room temperature to obtain supported X3MSx/Al2O3 catalyst with Miso-Vs synergistic sites. The method of the present invention achieves the joint enhancement of the activity, product selectivity, and stability of unsaturated carbon oxygen bond selective hydrogenation, carbon chlorine bond selective hydrogenation dechlorination, and carbon hydrogen bond dehydrogenation reactions. This catalyst is mainly used in various catalytic reaction processes in the fields of petrochemical, fine chemical, environmental chemical, and other fields. It has outstanding catalytic performance, excellent activity, selectivity, and good recyclability, and is easy to recover and reuse.

Claims

1. A preparation method of a supported metal catalyst with synergistic sites, characterized in that the preparation method comprises the following steps: A. Mix a soluble metal M salt solution uniformly with a solution of [X3S4(H2O)y]Clz cluster compound to obtain a [X3MS4(H2O)y+1]z+ solution; B. Disperse Al2O3 support uniformly into the solution obtained in step A, stir at the temperature of 2560 C. and the rotation speed of 200500 rpm for 26 h until it becomes sticky, and dry it in a constant temperature drying oven at 4080 C. for 824 h to obtain [X3MS4(H2O)y+1]z+/Al2O3 solid powder; C. Add 1.5 g solid powder obtained in step B into 530 mL of deionized water, add excessive soluble reducing agent to reduce M2+/M3+ to metal M, wherein the molar ratio of the reducing agent to the M salt is 3:17:1, stir for 1860 min to obtain black suspension, centrifugally wash it to neutrality, and dry it in a constant temperature drying oven at 60 C. for 816 h to obtain X3MS4/Al2O3; D. Place the X3MS4/Al2O3 obtained in step C into an atmosphere furnace, and heat it to 300600 C. at a rate of 520 C./min for 0.256 h of treatment to obtain X3MSx/Al2O3 catalyst (0<x<4); The corresponding treatment atmosphere is one of air, 10 vol. % O2/N2, 540 vol. % H2/N2 or 540 vol. % CO/N2; The corresponding X3MSx/Al2O3 catalyst possesses Miso-Vs synergistic sites.

2. A preparation method of a supported catalyst with synergistic sites according to claim 1, characterized in that the corresponding [X3S4(H2O)y]Clz in step A is a trinuclear transition metal-sulfur cluster compound with an unsaturated cubane structure, wherein X is one of Mo, W, Re and Ir; y=9; when X is Re (+3), z=1; when X is one of W, Mo and Ir(+4), z=4.

3. A preparation method of a supported catalyst with synergistic sites according to claim 1, characterized in that the corresponding soluble metal M salt in step A is one of Na2PdCl4, Pd(NO3)2, Pd(C5H7O2)2, H2PtCl6, Pt(NO3)2, CoCl2, Ni(NO3)2.Math.6H2O, NiCl2, RuCl3, Ga(NO3)3, Fe(NO3)3.Math.9H2O, CuCl2.Math.2H2O, Cu(NO3)2 and AgNO3.

4. A preparation method of a supported catalyst with synergistic sites according to claim 1, characterized in that the molar ratio of M to X3 in step A is 425/1, and the concentration of the M salt is 0.00350.0171 mol/L.

5. A preparation method of a supported catalyst with synergistic sites according to claim 1, characterized in that the theoretical loading of the soluble metal M salt in step B is 0.035.00 wt. % of the catalyst, preferably 0.052.50 wt. %; the corresponding Al2O3 support possesses rich pore structure while the crystalline phases is or , the specific surface area is 70190 m2/g, the pore volume is 0.31.3 cm3/g, and the pore size is 1530 nm; the soluble reducing agent in step C is one of NaBH4, LiBH4, ascorbic acid or oxalic acid.

6. A supported catalyst with synergistic sites according to claim 1, characterized in that the preparation method of a [X3 S4(H2O)y]Clz cluster solution comprises the following steps: Dissolve thiometalate in deionized water to prepare a solution with a concentration of 50120 mmol/L, alternately drop excessive reducing agent and acid solution, and fully stir at room temperature to obtain a suspension, crystallize it at 60100 C. for 1020 h, add acid solution dropwise to keep pH value of the suspension in the range of 13 during the crystallization process, and make it naturally cool down to room temperature after the color of the suspension turns dark green to obtain a [X3S4(H2O)y]Clz cluster solution.

7. A supported catalyst with synergistic sites prepared by the method according to claim 1, characterized in that the catalyst is expressed as MX3Sx/Al2O3, wherein x represents sulfur-containing number in the range of 0<x<4; MX3Sx is an active component, with M as an active metal being one of Pd, Pt, Co, Ni, Ru, Ga, Fe, Cu and Ag; X represents a transition metal being one of Mo, W, Re and Ir; Al2O3 is a support; and the corresponding loading of M is 0.035.00 wt. %; The structure of the catalyst is characterized in that the MX3Sx (0<x<4) active component is stably dispersed on the Al2O3 support, in which Miso presents a geometric site isolation, and forms a Miso-Vs synergistic sites with the adjacent S vacancies.

8. An application of a supported catalyst with synergistic sites prepared by the method according to claim 7 to catalyze the selective hydrogenation of unsaturated carbon-oxygen bonds, characterized in that the corresponding catalyst and 2-ethylanthraquinone working solution are weighed and loaded into a reactor, hydrogen is introduced into the reactor until the pressure reaches 0.3 MPa, the stirring is turned on at a rotation speed of 1000 rpm until the reactor is heated to 50 C., wherein the amount of the catalyst is 0.020.10 g, the reaction temperature is 4080 C., the rotation speed is 7001000 rpm, the 2-ethylanthraquinone working solution is 100150 g/L, and the test pressure is 14 bar. The liquid phase valve is opened every 30 minutes to take 1 mL working solution and mix it with 20 mL deionized water in a 250 mL separatory funnel and oxidize it with pure oxygen. When the upper organic phase turns from brownish black to bright yellow, stop introducing oxygen, and extract with deionized water for three times. The lower water phase obtained is titrated with 0.02 mol/L potassium permanganate solution under acidic conditions. Finally, the concentration of hydrogen peroxide is calculated.

9. An application of a supported catalyst with synergistic sites prepared by the method according to claim 7 to catalyze alkanes to produce olefins, characterized in that the catalyst is weighed and fully mixed with quartz sand possessing a particle size of 4070 meshes, and then loaded into a quartz tube reactor with a diameter of 8 mm, the feed gas composed of 2.0% propane/4% hydrogen/94% nitrogen equilibrium gas is introduced, wherein the molar ratio of hydrogen to alkane is 1/12/1. The catalytic performance is tested under the reaction temperature of 550580 C., pressure of 14 bar and space velocity of 30006000 h1. The composition and content of reactants and products are analyzed by gas chromatography with recording every 10 minutes.

10. An application of a supported catalyst with synergistic sites prepared by the method according to claim 7 to catalyze the selective hydrodechlorination of chlorine-containing organic compounds, characterized in that the catalyst is weighed and fully mixed with quartz sand possessing a particle size of 4070 meshes, and then loaded into a quartz tube reactor with a diameter of 7 mm, the feed gas composed of 0.14% dichloroethane/0.8% hydrogen/99.06% nitrogen equilibrium gas is introduced. A catalytic reaction is conducted under the certain conditions, wherein the amount of the catalyst is 0.020.50 g, the reaction temperature is 170500 C., the ratio of hydrogen to chlorine is 1/110/1, and the space velocity is 200012000 h1. The composition and content of reactants and products are analyzed by gas chromatography with recording every 10 minutes.

Description

[0024] FIG. 1 shows X-Ray Diffraction (XRD) results of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1, from which it can be seen that the prepared catalyst has an outstanding crystalline structure.

[0025] FIG. 2 shows CO-IR spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1. It can be seen that the linear adsorption peak of CO on palladium species appears above 2100 cm.sup.1, but there is no obvious CO bridging-adsorbed peak on Pd.sup.0, which indicates that the active Pd components in the catalyst exhibits no obvious agglomeration, while continuous Pd sites are effectively isolated.

[0026] FIG. 3 shows XPS spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and Pd/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1, where A is the Pd 3d XPS spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and Pd/Al.sub.2O.sub.3 catalyst, while B is the S 2p XPS spectrum of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst. It can be seen that the Pd site is electron-deficient, forming Pd.sup.+ species. Compared with Pd/Al.sub.2O.sub.3 catalyst, the electron cloud density of Pd species in Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst is reduced by using molybdenum-sulfur cluster as a precursor. After atmosphere treatment, there is no obvious signal of S species on the surface of the catalyst, indicating that the formation of S vacancy (V.sub.s).

[0027] FIG. 4 shows the ESR spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and pure Al.sub.2O.sub.3 prepared in Embodiment 1. It can be seen that an obvious S vacancy (g=2.003) is formed, which is related to the results in FIG. 3, indicating the existence of Pd.sup.+V.sub.s synergistic sites.

[0028] FIG. 5 shows the curve of hydrogenation efficiency versus time for the Pd.sup.+Mo.sub.3S.sub.x/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1 in the selective hydrogenation of anthraquinone. When the reaction time is 120 min, the hydrogenation efficiency reaches 15.7 g/L.

[0029] FIG. 6 shows the reusability of Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1 in selective hydrogenation reaction of anthraquinone. After the catalyst is reused for five times, the hydrogenation efficiency remains at 11.2 g/L and the target product selectivity is 96%2%.

[0030] FIG. 7 shows the catalytic results of the PtMo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 2 in propane dehydrogenation, where A is the curve of propane conversion versus time, and B is the curve of propylene selectivity versus time. When the reaction temperature is 580 C., the initial conversion is 68% and the propylene selectivity is 90%.

[0031] FIG. 8 shows the catalytic results of NiMo.sub.3S.sub.2.1/Al.sub.2O.sub.3 catalyst prepared in Embodiment 3 in the hydrodechlorination of dichloroethane, where A is the histogram of conversion and selectivity, and B is the reusability curve. When the reaction temperature is 300 C., the initial conversion is 85% and the olefin selectivity is 96%.

THE BENEFICIAL EFFECTS OF THE INVENTION

[0032] Based on the structural characteristics of trinuclear transition metal-sulfur cluster, a novel MX.sub.3S.sub.x/Al.sub.2O.sub.3 (0<x<4) catalyst with M.sub.iso-V.sub.s synergistic sites is obtained by utilizing the unsaturated cubane-like structure of the trinuclear transition metal-sulfur cluster, M cation with catalytic activity is introduced into the cluster core unit. By using the vertex vacancy as the capturing center, and adjusting the impregnation temperature to maximize the loading of the cluster precursor, as well as depending on the electrostatic adsorption of the support and the confinement of the cluster structural unit. The preparation method features simple process without the need of adding surfactant.

[0033] The prepared active metal components are uniformly dispersed on the surface of the support, which realizes the effective isolation of continuous M sites. By effectively controlling the number of S vacancies and the distance between S vacancies and M.sub.iso sites, X.sub.3MS.sub.x/Al.sub.2O.sub.3 catalyst with M.sub.iso-V.sub.s sites with enhanced synergistic effect is obtained. The catalyst can be applied to selective hydrogenation of CO bond, hydrodechlorination of CCl bond and dehydrogenation of CH bond, and exhibits excellent activity and selectivity, easy recovery and reuse, and good stability on the premise of reducing the amount of precious metals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 shows XRD results of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1.

[0035] FIG. 2 shows CO-IR spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1.

[0036] FIG. 3 shows the XPS spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and Pd/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1, where A is the Pd 3d XPS spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and Pd/Al.sub.2O.sub.3 catalyst, while B is the S 2p XPS spectrum of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst.

[0037] FIG. 4 shows the ESR spectra of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst and pure Al.sub.2O.sub.3 prepared in Embodiment 1.

[0038] FIG. 5 shows the curve of hydrogenation efficiency versus time of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1 in the selective hydrogenation of anthraquinone.

[0039] FIG. 6 shows the reusability of the Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 1 in selective hydrogenation reaction of anthraquinone.

[0040] FIG. 7 shows the catalytic results of the PtMo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared in Embodiment 2 in propane dehydrogenation, where A is the curve of propane conversion versus time, and B is the curve of propylene selectivity versus time.

[0041] FIG. 8 shows the catalytic results of NiMo.sub.3S.sub.2.1/Al.sub.2O.sub.3 catalyst prepared in Embodiment 3 in the hydrodechlorination of dichloroethane, where A is the histogram of conversion and selectivity, and B is the reusability curve.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiment 1

[0042] A. Stir and mix 5.64 mL soluble metallic Na.sub.2PdCl.sub.4 solution with a concentration of 50 mmol/L and 5 mL [Mo.sub.3S.sub.4(H.sub.2O).sub.9]Cl.sub.4 solution with a concentration of 12.8 mmol/L to obtain a solution containing heteronuclear Pd-based [Mo.sub.3PdS.sub.4(H.sub.2O).sub.10]Cl.sub.4 atomic cluster; [0043] B. Calcine pseudo-boehmite at 960 C. to obtain Al.sub.2O.sub.3 support with rich pore structure. According to the theoretical loading of the metallic M being 0.4 wt. %, disperse 1.5 g Al.sub.2O.sub.3 support uniformly into 10.64 mL mixed solution obtained in step A, continuously stir at 60 C. and 300 rpm for 4 h until it becomes sticky, and dry it in a constant temperature drying oven at 60 C. for 12 h to obtain [Mo.sub.3PdS.sub.4(H.sub.2O).sub.10]Cl.sub.4/Al.sub.2O.sub.3 solid powder; [0044] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0533 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and dry at 60 C. in a constant temperature drying oven for 12 h to obtain Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3; [0045] D. Place the Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 450 C. at the rate of 10 C./min in air and calcine it for 4 h to obtain the Mo.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Mo.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst (x=3) has Pd.sub.isoV.sub.s synergistic sites.

[0046] It can be seen from Table 1 that the catalyst has rich pore structure and large specific surface area.

TABLE-US-00001 TABLE 1 Test results of specific surface area and pore size of Al.sub.2O.sub.3 and PdMo.sub.3S.sub.3/Al.sub.2O.sub.3 Specific Specific Surface Area Pore Volume Pore Size Sample (m.sup.2/g) (cm.sup.3/g) (nm) Al.sub.2O.sub.3 87 0.37 16.69 Pd.sup.+Mo.sub.3S.sub.3/Al.sub.2O.sub.3 86 0.34 15.55

[0047] The corresponding prepared catalyst is used in the selective hydrogenation experiment of anthraquinone:

[0048] Weigh 25 mg of the corresponding catalyst and 60 mL 2-ethylanthraquinone working solution (120 g/L) and put them into a 100 mL reactor. Introduce hydrogen to 0.3 MPa, heat it to 50 C., and then turn on stirring (at a speed of 1,000 rpm), and periodically open the liquid valve to take 1 mL working solution for analysis. See the results in FIG. 5 and FIG. 6.

[0049] It can be seen from FIG. 5 that the hydrogenation efficiency of the catalyst reaches 15.7 g/L when the reaction time is 120 min. Compared with the 11.9 g/L in the Enhanced Catalytic Performance of PdGa Bimetallic Catalysts for 2-ethylanthraquinone Hydrogenation. Appl Organometal Chem. 2019, 33, e5076, the hydrogenation efficiency is significantly improved. It can be seen from FIG. 6 that the hydrogenation efficiency of the catalyst remains at 11.2 g/L and the target product selectivity is 96% 2% after reusing for five times.

Embodiment 2

[0050] A. Stir and mix 10.0 mL soluble metallic H.sub.2PtCl.sub.6 solution with a concentration of 15.0 mmol/L and [Mo.sub.3S.sub.4(H.sub.2O).sub.9]Cl.sub.4 solution at a Pt/Mo.sub.3S.sub.4 molar ratio of 1:1 to obtain a solution containing heteronuclear Pt-based [Mo.sub.3PtS.sub.4(H.sub.2O).sub.10]Cl.sub.4 atomic cluster; [0051] B. According to the theoretical loading of the metallic M being 2.00 wt. %, disperse 1.48 g Al.sub.2O.sub.3 support uniformly into the mixed solution obtained in step A, continuously stir at 60 C. and 300 rpm for 4 h until it becomes sticky, and dry it in a constant temperature drying oven at 60 C. for 24 h to obtain [Mo.sub.3PtS.sub.4(H.sub.2O).sub.10]Cl.sub.4/Al.sub.2O.sub.3 solid powder; [0052] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0533 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and dry it at 60 C. in a constant temperature drying oven for 12 h to obtain Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3; [0053] D. Place the Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 570 C. at the rate of 10 C./min in 10% H.sub.2/N.sub.2 and treat it for 0.33 h to obtain the Mo.sub.3PtS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Mo.sub.3PtS.sub.x/Al.sub.2O.sub.3 catalyst (x=3) has Pt.sub.iso-V.sub.s synergistic sites.

[0054] The catalyst is used in propane dehydrogenation:

[0055] Weigh 0.20 g catalyst and mix it with 1.80 g quartz sand with a particle size of 40-70 mesh thoroughly, and then load it into a quartz tube reactor with a diameter of 8 mm. The reaction feed gas is composed of 2.0% propane, 4% hydrogen and 94% nitrogen equilibrium gas, and the testing temperature is 580 C. The gas chromatography is used to analyze the composition and content of reactants and products. When the reactor reaches the specified temperature, records are made every 5 minutes. The results of propane conversion rate and selectivity of the catalyst at 580 C. are shown in Table 2.

TABLE-US-00002 TABLE 2 Catalytic performance Embodiment 1 Sample Selectivity (%) Conversion rate (%) Embodiment 2 90 68

[0056] The PtSn catalyst in the literature ACS Catal. 2021, 11, 8, 4401-4410 is a commonly used catalyst for industrial propane dehydrogenation, with a selectivity of 92% and a conversion rate of 40% for propane dehydrogenation at 600 C. It can be seen from Table 2 that compared with the PtSn catalyst reported in the literature, the PtMo.sub.3S.sub.3/Al.sub.2O.sub.3 catalyst prepared by the present invention has similar selectivity and more preferred activity at a lower temperature.

Embodiment 3

[0057] A. Stir and mix 6.7 mL soluble metallic Ni(NO.sub.3).sub.2.Math.6H.sub.2O solution with a concentration of 0.19 mol/L and 5 mL [Mo.sub.3S.sub.4(H.sub.2O).sub.9]Cl.sub.4 solution with a concentration of 12.8 mmol/L to obtain a solution containing heteronuclear Ni-based [Mo.sub.3NiS.sub.4(H.sub.2O).sub.10]Cl.sub.4 atomic cluster; [0058] B. According to the theoretical loading of metallic Ni being 2.5 wt. % of the catalyst, disperse 3.0 g Al.sub.2O.sub.3 support uniformly into 10.00 mL mixed solution obtained in step A, continuously stir at 60 C. and 400 rpm for 5 h until it becomes sticky, and dry it in a constant temperature drying oven at 60 C. for 12 h to obtain [Mo.sub.3NiS.sub.4(H.sub.2O).sub.10]Cl.sub.4/Al.sub.2O.sub.3 solid powder; [0059] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0533 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and dry it at 60 C. in a constant temperature drying oven for 12 h to obtain Mo.sub.3NiS.sub.4/Al.sub.2O.sub.3; [0060] D. Place the Mo.sub.3NiS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 450 C. at the rate of 10 C./min in 10 vol. % H.sub.2/N.sub.2 and conduct heat treatment for 3 h to obtain the Mo.sub.3NiS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Mo.sub.3NiS.sub.x/Al.sub.2O.sub.3 catalyst (x=2.1) has Ni.sub.isoV.sub.s synergistic sites.

[0061] The catalyst is used in the 1,2-dichloroethane hydrodechlorination:

[0062] Weigh 0.30 g catalyst and mix it with 1.40 g quartz sand with a particle size of 4070 mesh thoroughly, and then load it into a quartz tube reactor with a diameter of 7 mm. The reaction feed gas is composed of 92% 1,2-dichloroethane mixture and 8% hydrogen/nitrogen mixture, and the testing temperature is 300 C. The gas chromatography is used to analyze the composition and content of reactants and products. When the reactor reaches the specified temperature, records are made every 10 minutes. The results of 1,2-dichloroethane conversion rate and selectivity of the catalyst at 300 C. are shown in Table 3.

TABLE-US-00003 TABLE 3 Catalytic performance Embodiment 1 Sample Selectivity (%) Conversion rate (%) Embodiment 3 96 85

[0063] According to the literature Chem. Commun. 2020, 56, 6985, the selectivity of 17Ni-PC@SBA-15 catalyst for the hydrodechlorination of 1,2-dichloroethane at 300 C. is 90%, and the conversion is 65.5%. It can be seen from Table 3 that compared with the 17Ni-PC@SBA-15 catalyst reported in the literature, the selectivity and activity of the NiMo.sub.3S.sub.2.1/Al.sub.2O.sub.3 catalyst prepared by the present invention are higher than those of the above-mentioned 17Ni-PC@SBA-15 catalyst at the same temperature.

Embodiment 4

[0064] A. Stir and mix 5.64 mL soluble metallic Na.sub.2PdCl.sub.4 solution with a concentration of 50 mmol/L and 5 mL [Re.sub.3S.sub.4(H.sub.2O).sub.9]Cl solution with a concentration of 12.8 mmol/L to obtain a solution containing heteronuclear Pd-based [Re.sub.3PdS.sub.4(H.sub.2O).sub.9]Cl atomic cluster; [0065] B. Calcine pseudo-boehmite at 960 C. to obtain Al.sub.2O.sub.3 support with rich pore structure. Disperse 1.5 g Al.sub.2O.sub.3 support into 10.64 mL mixed solution obtained in step A at room temperature, with the loaded active metal Pd being 0.4 wt. %. Stir the mixture continuously for 4 h at 60 C. and 300 rpm until it becomes sticky, and dry it in a constant temperature drying oven at 60 C. for 12 h to obtain [Re.sub.3PdS.sub.4(H.sub.2O).sub.9]Cl/Al.sub.2O.sub.3 solid powder. [0066] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0533 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and have it dried at 60 C. in a constant temperature drying oven for 12 h to obtain Re.sub.3PdS.sub.4/Al.sub.2O.sub.3; [0067] D. Place the Re.sub.3PdS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 450 C. at the rate of 10 C./min in air and calcine it for 4 h to obtain the Re.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Re.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst (x=3) has Pd.sub.isoV.sub.s synergistic sites.

Embodiment 5

[0068] A. Stir and mix 14.10 mL soluble metallic Na.sub.2PdCl.sub.4 salt solution with a concentration of 50 mmol/L and 5 ml [Mo.sub.3S.sub.4(H.sub.2O).sub.9]Cl.sub.4 solution with a concentration of 12.8 mmol/L to obtain a solution containing heteronuclear Pd-based [Mo.sub.3PdS.sub.4(H.sub.2O).sub.10] atomic cluster; [0069] B. Calcine pseudo-boehmite at 960 C. to obtain Al.sub.2O.sub.3 support with rich pore structure. Disperse 1.5 g Al.sub.2O.sub.3 support into 12.05 mL mixed solution obtained in step A at room temperature, in which the supported active metal Pd is 1.0 wt. %. Stir the mixture continuously for 4 h at 40 C. and 300 rpm until it becomes sticky, and dry it in a constant temperature drying oven at 40 C. for 12 h to obtain [Mo.sub.3PdS.sub.4(H.sub.2O).sub.10]Cl.sub.4/Al.sub.2O.sub.3 solid powder. [0070] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0666 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and dry it at 60 C. in a constant temperature drying oven for 12 h to obtain Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3; [0071] D. Place the Mo.sub.3PdS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 450 C. at the rate of 10 C./min in air and calcine it for 4 h to obtain the Mo.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Mo.sub.3PdS.sub.x/Al.sub.2O.sub.3 catalyst (x=3) has Pd.sub.isoV.sub.s synergistic sites.

Embodiment 6

[0072] A. Stir and mix 6.7 mL soluble metallic CuCl.sub.2.Math.2H.sub.2O solution with a concentration of 0.19 mol/L and 5 mL [Mo.sub.3S.sub.4(H.sub.2O).sub.9]Cl.sub.4 solution with a concentration of 12.8 mmol/L to obtain a solution containing heteronuclear Cu-based [Mo.sub.3CuS.sub.4(H.sub.2O).sub.10]Cl atomic cluster; [0073] B. According to the theoretical loading of metallic Cu being 2.50 wt. %, disperse 3.0 g Al.sub.2O.sub.3 support uniformly into 10.00 mL mixed solution obtained in step A, continuously stir at 60 C. and 400 rpm for 5 h until it becomes sticky, and dry it in a constant temperature drying oven at 60 C. for 12 h to obtain [Mo.sub.3CuS.sub.4(H.sub.2O).sub.10]Cl.sub.4/Al.sub.2O.sub.3 solid powder; [0074] C. Add 1.5 g solid powder obtained in step B into 10 mL deionized water, add 0.0533 g NaBH.sub.4 as a reducing agent, stir for 30 minutes, centrifuge and wash the obtained black suspension to neutral while washing away soluble sodium salts, and dry it at 60 C. in a constant temperature drying oven for 12 h to obtain Mo.sub.3CuS.sub.4/Al.sub.2O.sub.3; [0075] D. Place the Mo.sub.3CuS.sub.4/Al.sub.2O.sub.3 obtained in step C into an atmosphere furnace, heat it to 400 C. at the rate of 5 C./min in 10 vol. % H.sub.2/N.sub.2 and conduct heat treatment for 3 h to obtain the Mo.sub.3CuS.sub.x/Al.sub.2O.sub.3 catalyst; and the corresponding Mo.sub.3CuS.sub.x/Al.sub.2O.sub.3 catalyst (x=2.5) has Cu.sub.isoV.sub.s synergistic sites.