CN112916030A

CN112916030A - Pt/alpha-MoC1-xPreparation method and application of water-vapor shift catalyst

Info

Publication number: CN112916030A
Application number: CN201911239218.1A
Authority: CN
Inventors: 丛昱; 陈帅; 许国梁; 吴春田; 唐南方
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2021-06-08
Anticipated expiration: 2039-12-06
Also published as: CN112916030B

Abstract

The invention relates to a Pt/alpha-MoC_1‑x(0<x<0.5) preparation method and application of the water-gas shift catalyst. The invention provides a method for passing MoO₃Preparation of Pt/alpha-MoC by partial reduction-impregnation-in-situ carbonization_1‑xA process for the water-gas shift of catalyst. The catalyst has excellent water-vapor transformation reaction catalytic performance: the activity of the catalyst is obviously higher than that of commercial Cu/ZnO/Al₂O₃Low temperature shift catalyst, also superior to Pt/Mo prepared by conventional method₂C, a catalyst; the catalyst also has a wide temperature adaptation range of 100-400 DEG CThe inside of the enclosure has higher activity; meanwhile, the catalyst also shows excellent stability, and the molar ratio of water to CO is 2.5:1 at the temperature of 175 ℃, and the mass space velocity is 270000 ml.h^‑1·g^‑1 _{Catalyst and process for preparing same}Under the conditions of (1), the CO conversion rate is maintained to be more than 95% within 50 hours. The preparation method of the catalyst is simple and controllable, and the prepared catalyst has high water-vapor conversion activity, good stability and wide temperature application range, is suitable for the application environment of the vehicle-mounted hydrogen fuel cell, and has good application prospect.

Description

Pt/alpha-MoC1-xPreparation method and application of water-vapor shift catalyst

Technical Field

The invention relates to a Pt/alpha-MoC_1-xA preparation method of a catalyst and an application of the prepared catalyst in a water-vapor shift reaction belong to the technical field of new energy.

Background

The fuel cell is a device for efficiently converting chemical energy into electric energy, and the conversion process does not involve thermal cycle, so the energy conversion efficiency is not limited by Carnot cycle, and the actual conversion efficiency is 2-3 times of that of a common internal combustion engine. The fuel cell has the advantages of flexible scale, environmental friendliness, high reliability and the like, and has wide application prospects in aerospace, automobiles and other fixed and mobile energy sources. Currently, the more mature fuel cells use primarily hydrogen fuel. However, the density of hydrogen is low, and for vehicle-mounted applications, the hydrogen is required to be compressed to a high pressure, generally up to 70MPa, by adopting a hydrogen cylinder to carry hydrogen, which puts high requirements on the material and production process of the hydrogen cylinder. In addition, hydrogen is a highly flammable and explosive substance, and once leakage occurs, there is a high possibility of causing a fire or explosion. Therefore, the fuel cell vehicle using the gas cylinder to carry hydrogen has the defects of high cost and high safety risk, and the best mode for solving the problem is to utilize common fuel to produce hydrogen on line. That is, a raw material processor is added in front of the fuel cell to perform steam reforming reaction or autothermal reforming reaction on fuel such as natural gas, liquefied petroleum gas, gasoline, diesel oil, methanol, ethanol and the like to produce hydrogen.

In the reforming process of the fuel, the reformate is generally CO and H₂And CO₂The mixed gas of (2), wherein the CO content is generally 5 to 12%. CO is not only an environmentally polluting gas, but also poisons the platinum catalyst of the fuel cell, which is responsible for the CO content of the feedstockThe requirement is less than 10 ppm. In order to remove CO in the mixed gas, the concentration of CO is reduced to 0.5-1% by adopting a water-gas shift reaction, and then the concentration of CO is reduced to below 10ppm by utilizing a CO selective oxidation reaction. Therefore, the water-gas shift process is indispensable for fuel cells, and the development of a high-efficiency water-gas shift catalyst is an important subject for the process.

In the current industrial hydrogen production technology, a two-stage water-vapor conversion mode is generally adopted to reduce the concentration of carbon monoxide, namely high-temperature conversion and low-temperature conversion. The temperature of the high-temperature shift reaction is usually 350-450 ℃, the widely used catalyst is Fe-Cr catalyst, and the concentration of CO can be reduced to 2-3%; the temperature of the low-temperature shift reaction is generally 190-250 ℃, and the common catalyst is Cu/ZnO/Al₂O₃The catalyst can reduce the CO concentration to below 0.5%. The traditional industrial water-vapor shift catalyst has the problems of complex pretreatment process, incapability of starting and stopping quickly, low activity, easiness in poisoning and the like, cannot meet the requirement of a small-scale CO water-vapor shift process required by a fuel cell, and needs to develop an efficient water-vapor shift catalyst.

In order to meet the requirements of the fuel cell, the water-gas shift catalyst needs to simultaneously meet the following conditions: (1) the activity is high, and is obviously higher than that of the existing Cu/ZnO/Al₂O₃A low temperature shift catalyst to reduce catalyst carry-over and ensure that the CO converter volume and weight in the on-board fuel processor are within the allowable range for on-board applications; (2) the active temperature zone is wide, and the active temperature zone needs to have strong thermal stability and the capability of resisting frequent thermal shock and thermal fluctuation; (3) when the catalyst meets the condition that air is not self-ignited, namely, the catalyst has oxygen resistance, and has toxicity resistance and condensed water resistance, namely, the catalyst is not sensitive to air and water.

Molybdenum carbide, as a novel catalytic material with excellent performance, has been found in research reports of forward and reverse water vapor conversion, hydrogenation, dehydrogenation, fischer-tropsch synthesis, electrocatalytic reaction and the like. Thompson et al (J.Am. chem.Soc.,2011,13,3,82378-81) have found that 2 wt% Pt/Mo supported metals (Ni, Pt, Co, etc.) on unpassivated molybdenum carbide surfaces (metals supported on fresh carbide surfaces, not passivated carbide surfaces) and that 2 wt% Pt/Mo was found₂C catalystActivity in water-gas shift reaction and commercial Cu/ZnO/Al₂O₃The catalyst is equivalent; 4 wt% Pt/Mo₂The activity of the C catalyst is commercial Cu/ZnO/Al₂O₃3-4 times of the catalyst, but the using temperature of the catalyst is 240 ℃, and the applicable temperature is higher. Thompson et al (Journal of Catalysis,2015,330,280-287) also found that Pt/Mo₂The oxygen in the catalyst C has obvious influence on the structure and the activity of the catalyst, and even a small amount of oxygen in the catalyst can obviously reduce the activity of the catalyst. Chinese patent CN102698783A discloses a metal modified alpha molybdenum carbide water vapor shift catalyst which has good low-temperature water vapor shift activity but poor reaction stability, and when the reaction temperature is 150 ℃, the CO conversion rate is reduced from 96% to 76% within 24 hours. Yao et al (Science,2017,357, 389-393) reported an Au/alpha-MoC catalyst which has higher low-temperature water-vapor shift reaction activity, but the activity of the catalyst is rapidly reduced at the temperature of more than 200 ℃, the problems of poor temperature adaptability, narrow applicable temperature range and poor reaction stability exist, and the CO conversion rate of the catalyst is reduced from 90% to less than 50% within 140 h. Chinese patent CN104923274B discloses a pure alpha-phase molybdenum carbide supported noble metal catalyst, which has high low-temperature water-vapor conversion activity, but does not see data of temperature adaptability and reaction stability, and the preparation process of the catalyst is also complicated, and non-equilibrium plasma treatment is required.

Disclosure of Invention

Based on the current research situation, the invention provides a Pt/alpha-MoC_1-xThe preparation method of the water-vapor shift catalyst and the application of the catalyst in the water-vapor shift reaction solve the problems that the catalyst in the prior art has poor low-temperature water-vapor shift activity, narrow applicable temperature range, poor reaction stability and the like, which do not meet the application requirements of fuel cells. The invention provides a method for preparing a compound by MoO₃Method for preparing catalysts by partial reduction, impregnation and in-situ carbonization, in one aspect MoO₃Partial reduction to obtain MoO with higher specific surface area_yImproving the dispersion degree of the metal platinum, and on the other hand, Pt and alpha-MoC are generated in the carbonization process_1-xForm stronger interaction between them, so that the catalyst isHas strong capability of resisting water oxidation. Meanwhile, an in-situ activation method is adopted, the existing state of the active center is optimized, and the reaction activity and the stability of the catalyst are greatly improved. Therefore, the catalyst provided by the invention has the advantages of high activity, wide operating temperature range, good stability and simple and controllable preparation process, and is expected to meet the application requirements of miniaturization and portability of hydrogen production fuel cell equipment in a vehicle-mounted environment.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the invention provides a Pt/alpha-MoC in a first aspect_1-xThe preparation method of the water-gas shift catalyst comprises the following steps:

(1) adding MoO₃Placing the solid powder in a tubular furnace, raising the temperature by a program at a speed of 1-20 ℃/min under a hydrogen atmosphere, reducing for 1-20h at 200-600 ℃, wherein the hydrogen concentration is 10-100% (molar concentration), and the hydrogen flow is 100-1000 ml.min^-1·g^-1 _MoO3After the reduction, the inert atmosphere was reduced to room temperature, and the solid powder obtained was recorded as MoO_y。

(2) With the MoO obtained in step (1)_yThe solid powder is used as a carrier, soluble salt of active metal platinum is loaded on the carrier by adopting an impregnation method, and then the carrier is dried for 4-24 hours at the temperature of 80-180 ℃. Transferring the mixture into a tube furnace, raising the temperature by a program at a speed of 1-20 ℃/min under the air atmosphere or inert atmosphere, and roasting at 200-700 ℃ for 0.5-10 h to obtain Pt-MoO_y。

(3) Taking the Pt-MoO obtained in the step (2)_yPlacing the mixture in a fixed bed reactor, heating the mixture from room temperature to 500-800 ℃ at a heating rate of 1-20 ℃/min in a mixed gas of a carbon source and hydrogen, carbonizing the mixture, and keeping the temperature for 1-20 hours, wherein the gas flow is 100-1000 ml/min^-1·g^-1 _MoOxObtaining Pt/alpha-MoC_1-xA catalyst.

The heating rate in the step (1) is preferably 3-15 ℃/min, and more preferably 5-10 ℃/min; the reduction temperature is preferably 250-500 ℃, and more preferably 300-400 ℃; the reduction time is preferably 3-15 h, and more preferably 6-12 h; the concentration of the hydrogen is preferably 20-100%; furthermore, the utility modelPreferably 50 to 100 percent; the flow rate of the hydrogen atmosphere is preferably 200 to 800 ml/min^-1·g^-1 _MoO3More preferably 300 to 600 ml/min^-1·g^-1 _MoO3(ii) a The inert atmosphere is one or more than two of nitrogen, argon and helium.

The soluble salt of platinum in the step (2) is one or more than two of chloroplatinic acid, platinum chloride, platinum nitrate, platinum tetraammine dichloride, platinum tetraammine nitrate, platinum tetraammine acetate or platinum acetylacetonate; the drying temperature is preferably 100-140 ℃, and more preferably 110-130 ℃; the drying time is preferably 2-10 h, and more preferably 4-6 h; the heating rate is preferably 3-15 ℃/min, and more preferably 5-10 ℃/min; the roasting time is preferably 1-6 h, and more preferably 2-5 h; the roasting temperature is preferably 300-600 ℃, and more preferably 400-500 ℃.

In the mixed gas of the carbon source and the hydrogen in the step (3), the molar concentration of the carbon source is 10-50%, preferably 15-40%, and more preferably 20-30%; the carbon source is one or more than two of methane, ethane, ethylene, propane and propylene. The heating rate is preferably 5-15 ℃/min, and more preferably 8-12 ℃/min; the carbonization temperature is preferably 550-750 ℃, and more preferably 600-700 ℃; the preferred gas flow is 200-800 ml/min^-1g^-1 _MoOyMore preferably 300 to 600 ml/min^-1g^-1 _MoOy(ii) a The carbonization time is preferably 2-10 h, and more preferably 3-5 h.

In a second aspect, the present invention provides Pt/α -MoC prepared by the above method_1-xThe water vapor transformation catalyst, wherein the content of the metal platinum in the catalyst is 0.1-30 wt%, preferably 0.5-15 wt%, and more preferably 1-5 wt%; alpha-MoC of the catalyst support_1-xWherein 0 is<x<0.5。

In a third aspect, the present invention provides the above Pt/α -MoC_1-xThe application of the catalyst, wherein the catalyst is used for CO water vapor shift reaction. The Pt/alpha-MoC obtained after carbonization_1-xThe catalyst is reduced to the reaction temperature under the carbonization atmosphere, and the carbonization atmosphere is switchedThe reaction gas is subjected to water-vapor transformation reaction, and the applicable reaction conditions are as follows: the molar ratio of water to CO is (0.5-10): 1, preferably (1-6): 1, more preferably (2-3): 1; the mass space velocity of the reaction gas passing through the catalyst bed layer is 5000-2000000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}(ii) a Preferably 10000-1500000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}More preferably 20000 to 1000000ml · h^-1·g^-1 _{Catalyst and process for preparing same}(ii) a The pressure of the reaction system is 0.1-4 MPa, preferably 0.1-2 MPa, and more preferably 0.1-1 MPa; the reaction temperature is 50-400 ℃, preferably 80-300 ℃, and more preferably 150-250 ℃.

The flow of the reaction evaluating apparatus for verifying the technical scheme of the present invention is shown in fig. 1. The raw material gas is metered by a flowmeter and then enters a preheater, and the water is quantitatively conveyed by a metering pump and enters the preheater. The mixed material is preheated to 100-400 ℃ in a preheater, the preheated material enters a reactor (c) arranged in a heating area in a reaction furnace (c), a catalyst bed layer (0) is arranged in a constant-temperature area of the reactor (c), the reacted material is separated into a gas-phase product and condensed water through a condenser (c 1), the condensed water is discharged from a stop valve (c 2) at a proper time, and the gas product passes through a back pressure valve

After reducing to normal pressure, the gas passes through a gas flowmeter

Emptying after metering, and emptying pipeline

Is provided with a sampling branch for a gas chromatograph

Sampling and analyzing.

As described above, the present invention provides Pt/α -MoC_1-xThe preparation method of the catalyst and the application thereof in the water-gas shift reaction have the following technical advantages:

the invention is through MoO₃Is partially alsoThe original-impregnation-in-situ carbonization method is used for preparing Pt/alpha-MoC with high specific surface area and highly dispersed active metal_1-xA water-gas shift catalyst. The experimental result shows that the prepared catalyst has excellent catalytic performance of water-vapor transformation reaction: (1) the catalyst has a water-CO molar ratio of 2.5:1 and a space velocity of 90000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}Under the condition of 40% H₂/15％CO/13％CO₂The raw material gas with high concentration CO and rich hydrogen of 32% Ar has high transformation activity, and the CO conversion rate reaches 98% at 150 ℃; under the same conditions, the CO conversion rate of the commercial Cu-Zn-Al catalyst is not more than 5 percent; and the conversion rate of CO of the Pt/molybdenum carbide catalyst prepared by the conventional method is only about 10 percent under the same condition. (2) The catalyst shows good reaction stability, and the reaction temperature is 175 ℃, and the space velocity is 270000 ml.h when the molar ratio of water to CO is 2.5:1^-1·g^-1 _{Catalyst and process for preparing same}The raw materials are converted under the condition, and the CO conversion rate is always maintained to be more than 95 percent within 50 hours. (3) The catalyst has a wide temperature application range, and 360000 ml.h in the range of 175-350 DEG C^-1·g^-1 _{Catalyst and process for preparing same}The CO conversion level is close to the thermodynamic equilibrium conversion at the space velocity of (a). The preparation method of the catalyst is simple and controllable, and the prepared catalyst is high in activity, good in stability, wide in temperature application range, suitable for the application requirements of vehicle-mounted environments and good in application prospect.

Drawings

FIG. 1 is a schematic flow diagram of a CO water-vapor shift reaction evaluation device;

CO material gas, flowmeter, water, metering pump, preheater, reactor, catalyst bed layer, condenser and cut-off valve,

a back pressure valve is arranged on the back pressure valve,

a gas flow meter is arranged on the gas inlet pipe,

a gas chromatograph,

and (5) emptying the pipeline.

FIG. 2 shows the data of the water-gas shift reaction test obtained in examples 4 to 6 and comparative examples 1 and 3.

FIG. 3 is a graph showing experimental data of the water-gas shift reaction obtained in examples 7 to 9 and comparative examples 4 to 5.

FIG. 4 shows experimental data on the water vapor shift reaction obtained in example 10 and comparative example 6.

FIG. 5 is the data for the stability test of the water-gas shift reaction obtained in example 11.

Detailed Description

The present invention is further illustrated by the following examples, but the present invention is not limited to these examples.

Example 1

(1) 2.80g of MoO₃Placing the solid powder in a tubular furnace, heating from room temperature to reduction temperature at a speed of 5 ℃/min under a hydrogen/nitrogen mixed atmosphere with a hydrogen molar concentration of 10%, reducing for 10h at 400 ℃, wherein the flow rate of the hydrogen/nitrogen mixed gas is 600 ml/min^-1After the reduction, the atmosphere of high-purity nitrogen was reduced to room temperature, and the solid powder obtained was recorded as MoO_yAnd y is 2.2-2.3 through thermogravimetric detection.

(2) With the MoO obtained in step (1)_yTaking solid powder as a carrier, weighing chloroplatinic acid (20 wt%) solution with platinum loading of 2 wt%, and mixing the solution according to the weight ratio of 1: 1 volume ratio impregnation to MoO_yThe support was dried at 100 ℃ for 2 h. Transferring the catalyst precursor to a tubular furnace after drying, placing the dried product in an air atmosphere, raising the temperature to a roasting temperature at a speed of 10 ℃/min, roasting for 3h at 500 ℃ in the air atmosphere, and obtaining 2Pt-MoO_y。

(3) And (3) directly tabletting and molding the powdery catalyst obtained in the step (2), and crushing the powdery catalyst into particles of 20-40 meshes. Mixing 0.2g of granular catalyst and 0.5g of quartz sand (20-40 mesh), placing in a fixed bed reactor shown in figure 1, and introducing at flow rate of 150 ml/min^-1Methane, methaneThe methane/hydrogen gas with the molar concentration of 20 percent is carbonized in the atmosphere, the temperature is increased from room temperature to 600 ℃ at the temperature rising rate of 20 ℃/min, the carbonization is carried out for 2 hours, and then the temperature is reduced to the reaction temperature in the carbonization atmosphere to obtain Pt/alpha-MoC_1-xCatalyst, characterization of the support as alpha phase MoC by XRD_1-xX is 0.31 measured by thermogravimetry, and the mass content of metal platinum in the catalyst measured by ICP is 1.95%.

Example 2:

example 1 was repeated except that the chloroplatinic acid solution was weighed in step (2) in an amount of 1% by weight of the platinum loading.

Example 3:

example 1 was repeated except that the hydrogen concentration in step (1) was changed to 100% pure hydrogen.

Example 4:

evaluation of CO water vapor shift reaction:

Pt/alpha-MoC obtained in example 1_1-xThe catalyst is directly subjected to water-gas shift reaction evaluation. The composition of the reaction raw material gas is 40 percent of H₂/15％CO/13％CO₂32% Ar, water to carbon monoxide molar ratio of 2.50, total reaction gas feed flow of 300ml min^-1Converted into a mass space velocity (WHSV) of about 90000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The reaction pressure is 0.1MPa, the reaction temperature is 150 ℃, 200 ℃, 250 ℃, 300 ℃, 350 ℃ and 400 ℃ respectively, and the reaction is carried out for 1h at each temperature, and the specific result is shown in figure 2.

Example 5:

example 4 was repeated except that the catalyst used was the catalyst prepared in example 2, and the specific results are shown in FIG. 2.

Example 6:

example 4 was repeated except that the catalyst used was the catalyst prepared in example 3, and the specific results are shown in FIG. 2.

Example 7:

example 4 was repeated except that the reaction mixture gas feed rate was 1200 ml/min^-1Converted into mass space velocity of about 360000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 3.

Example 8:

example 5 was repeated except that the reaction mixture gas feed rate was 1200 ml. h^-1Converted into mass space velocity of about 360000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 3.

Example 9:

example 6 was repeated except that the reaction mixture gas feed rate was 1200 ml/min^-1Converted into mass space velocity of about 360000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 3.

Example 10:

example 5 was repeated except that the reaction mixture gas feed rate was 600 ml/min^-1Converted into a mass space velocity of about 180000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 4.

Example 11:

example 4 was repeated except that the reaction mixture gas feed rate was 900 ml/min^-1Converted into mass space velocity of about 270000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The reaction temperature was fixed at 175 ℃, the analysis results were sampled every 1h, and the stability of the catalyst was examined for 50 hours, and the specific results are shown in fig. 5.

Comparative example 1:

example 4 was repeated except that the catalyst used was changed to commercial Cu/ZnO/Al₂O₃The results are shown in FIG. 2.

Comparative example 2:

pt/molybdenum carbide catalyst prepared by conventional method: example 1 was repeated except that MoO was used directly₃The MoO in step (1) is omitted as the raw material₃The reduction process of (2) and catalyst preparation are carried out to obtain the Pt/molybdenum carbide catalyst by the conventional method.

Comparative example 3:

example 4 was repeated except that the catalyst used was changed to the catalyst prepared in comparative example 2, and the specific results are shown in FIG. 2.

Comparative example 4:

repetition ofComparative example 1 except that the reaction mixture gas feed rate was 1200 ml/min^-1Converted into mass space velocity of about 360000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 3.

Comparative example 5:

comparative example 3 was repeated except that the reaction mixture gas feed rate was 1200 ml. min^-1Converted into mass space velocity of about 360000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 3.

Comparative example 6:

comparative example 3 was repeated except that the reaction mixture gas feed rate was 600 ml. min^-1Converted into a mass space velocity of about 180000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}The specific results are shown in FIG. 4.

As can be seen from figures 2-5, the catalyst provided by the invention shows excellent water-vapor transformation reaction activity, and the activity is obviously higher than that of commercial Cu/ZnO/Al₂O₃The low-temperature shift catalyst is also superior to a Pt/molybdenum carbide catalyst prepared by a conventional method, and particularly has more obvious activity advantage at a lower temperature (150-250 ℃). As can be seen from FIG. 5, the catalyst provided by the present invention also exhibits excellent stability at a water to CO molar ratio of 2.5:1 and a mass space velocity of 270000 ml. h^-1·g^-1 _{Catalyst and process for preparing same}Under the condition, the CO conversion rate is maintained to be more than 95% within 50 hours, and the catalyst provided by the invention is shown to have better activity than a commercial catalyst and good stability. As can be seen from FIG. 3, the catalyst provided by the invention has a wide temperature application range, and the CO conversion rate is very high in a range of 175-400 ℃, is close to the equilibrium conversion rate, and shows good temperature adaptability of the catalyst.

The catalyst provided by the invention has good activity and stability in a water vapor shift reaction, is simple and controllable in preparation process, high in activity, good in stability, wide in temperature application range, suitable for high airspeed operation conditions required by vehicle-mounted and small-scale hydrogen production environments, and has good application prospects.

Claims

1. Pt/alpha-MoC_1-xThe preparation method of the water-gas shift catalyst is characterized by comprising the following steps:

(1) adding MoO₃The solid powder is heated in a hydrogen atmosphere by a temperature programming method at a speed of 1-20 ℃/min from room temperature to a reduction temperature, wherein the heating speed is preferably 3-15 ℃/min, and more preferably 5-10 ℃/min; reducing for 1-20h at 200-600 ℃ with gas flow of 100-1000 ml/min^-1·g^-1 _MoO3The reduction temperature is preferably 250-400 ℃, and more preferably 300-400 ℃; the reduction time is preferably 3-15 h, more preferably 6-12 h, and the flow rate of the reduction gas is preferably 200-800 ml/min^-1·g^-1 _MoO3More preferably 300 to 600 ml/min^-1·g^-1 _MoO3(ii) a After the reduction, the temperature was reduced to room temperature in an inert atmosphere, and the solid powder obtained was recorded as MoO_yWherein 2 is<y<3；

(2) MoO obtained in step (1)_ySolid powder is used as a carrier, soluble salt of active metal platinum is loaded on the carrier by adopting an impregnation mode, and the carrier is dried for 4-24 hours at the temperature of 80-180 ℃, wherein the drying temperature is preferably 100-140 ℃, more preferably 110-130 ℃, and the drying time is preferably 2-10 hours, more preferably 4-6 hours; placing the dried product in an air atmosphere and/or an inert atmosphere, and carrying out temperature programming at a rate of 1-20 ℃/min to reach the roasting temperature, wherein the heating rate is preferably 3-15 ℃/min, and more preferably 5-10 ℃/min; the roasting temperature is 200-700 ℃, the roasting temperature is preferably 300-600 ℃, and more preferably 400-500 ℃; the roasting time is 0.5-10 h, preferably 1-6 h, more preferably 2-5 h, and the Pt-MoO is obtained_y；

(3) The Pt-MoO obtained in the step (2) is treated_yTemperature programming is carried out in a mixed gas containing a carbon source and hydrogen at the speed of 1-20 ℃/min from room temperature to the carbonization temperature, wherein the heating speed is preferably 5-15 ℃/min, and more preferably 8-12 ℃/min; carbonizing for 1-20 hours at 500-800 ℃, wherein the carbonization temperature is preferably 550-750 ℃, more preferably 600-700 ℃, and the carbonization time is preferably 2-10 hours, more preferably 3-5 hours; the gas flow rate is 100-1000 ml/min^-1·g^-1 _Pt-MoOyThe preferable flow rate of the carbonized gas is 200-800 ml/min^-1g^-1 _MoOyMore preferably 300 to 600 ml/min^-1g^-1 _MoOy(ii) a Obtaining Pt/alpha-MoC_1-xCatalyst of which 0<x<0.5。

2. The method for preparing the catalyst according to claim 1, wherein: the hydrogen atmosphere in the step (1) is hydrogen or a mixed gas of hydrogen and inert gas, and the molar concentration of the hydrogen in the hydrogen atmosphere is 10-100%, preferably 20-100%; more preferably 50 to 100%.

3. The method for preparing a catalyst according to claim 1 or 2, characterized in that: the inert atmosphere is one or more than two of nitrogen, argon and helium.

4. The method for preparing the catalyst according to claim 1, wherein: in the step (2), the soluble salt of platinum is one or more of chloroplatinic acid, platinum chloride, platinum nitrate, platinum tetraammine dichloride, platinum tetraammine nitrate, platinum tetraammine acetate or platinum acetylacetonate.

5. The method for preparing the catalyst according to claim 1, wherein: in the step (3), the molar concentration of the carbon source in the mixed gas of the carbon source and the hydrogen is 10-50%, preferably 15-40%, and more preferably 20-30%, and the carbon source is one or more of methane, ethane, ethylene, propane, and propylene.

6. A catalyst prepared by the preparation method of any one of claims 1 to 5, wherein: the mass content of the metal platinum in the catalyst is 0.1-30%, preferably 0.5-15 wt%, and more preferably 1-5 wt%; the carrier of the catalyst is alpha-MoC_1-x。

7. Use of a catalyst according to claim 6, wherein: the catalyst is used for a water-gas shift reaction.

8. Use according to claim 7, characterized in that: the catalyst is applicable to the water-vapor transformation reaction conditions as follows: the molar ratio of water to CO in the reaction gas is (0.5-10): 1, preferably (1-6): 1, more preferably (2-3): 1; the reaction gas contains no or unnecessary components, and the unnecessary component is N₂、CO₂、H₂One or more than two of Ar and He, wherein the mole fraction of the unnecessary components in the reaction gas is 0-90%; the mass space velocity of the reaction gas is 5000-2000000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}Preferably 10000-1500000 ml.h^-1·g^-1 _{Catalyst and process for preparing same}More preferably 20000 to 1000000ml · h^-1·g^-1 _{Catalyst and process for preparing same}(ii) a The pressure of the reaction system is 0.1 to 4MPa, preferably 0.1 to 2MPa, and more preferably 0.1 to 1 MPa.

9. Use according to claim 7, characterized in that: the reaction temperature is 50-400 ℃, preferably 80-300 ℃, and more preferably 150-250 ℃.