CN113117712B - Methane dry reforming reaction under microwave condition and catalyst thereof - Google Patents

Abstract

The invention provides a methane dry reforming reaction under the microwave condition and a catalyst thereof. The dry reforming reaction of methane uses a catalyst comprising a composite metal oxide M/CaZrO₃And SiC on CH under microwave conditions₄And CO₂Catalytic reforming to produce H as the main product₂And CO, wherein M is at least one metal element of Ni and Co. The dry reforming reaction of methane provided by the invention has the advantages of low reaction temperature, low energy consumption, high conversion rate of methane and carbon dioxide, long-term maintenance of good activity of the catalyst in the use process, and good stability.

Description

Methane dry reforming reaction under microwave condition and catalyst thereof

Technical Field

The invention belongs to the technical field of catalysts, and particularly relates to a methane dry reforming reaction under a microwave condition and a catalyst thereof.

Background

Methane is a new energy source to be regarded as a future petroleum substitute, but it is difficult to convert it into a high-value chemical product. Methane is also a greenhouse gas, and methane in the atmosphere can cause climate warming. The other reactant, carbon dioxide, is the most dominant greenhouse gas, and carbon dioxide capture, storage and conversion is now gaining attention worldwide. The conversion and utilization of methane and carbon dioxide are therefore receiving increasing attention.

Dry reforming of methane is important because of the ability to convert two greenhouse gases simultaneouslyThe use of valuable syngas is considered to be a very potential method for future methane conversion and reduction of carbon dioxide content. The reaction formula of the dry reforming of methane is as follows: CH (CH)₄+CO₂→2H₂+2CO, although the reaction is theoretically capable of complete conversion. However, since this reaction is a strongly endothermic reaction (. DELTA.H =247 kJ/mol), up to 1000 ℃ is required for the reaction conversion. This would entail a considerable energy loss, and it would therefore be desirable to find a way to reduce the energy consumption of the reaction.

In the related art, the transition metal catalyst has certain activity in the dry reforming reaction of methane, and the transition metal is low in price compared with noble metals, but the common transition metal catalyst cannot maintain the high-efficiency conversion of methane and carbon dioxide for a long time, is poor in stability, and has the problem of high operation cost caused by overhigh reaction temperature. Therefore, it is necessary to develop a catalyst which can convert methane and carbon dioxide at a relatively low temperature with high efficiency and has good stability.

Disclosure of Invention

The invention aims to provide a dry reforming reaction of methane, which uses a novel catalyst to efficiently convert methane and carbon dioxide under the microwave condition, has low reaction temperature and low energy consumption, can keep higher activity for a long time in the using process of the catalyst, and has good stability.

In order to achieve the aim, the invention provides a methane dry reforming reaction under microwave condition, which uses a composite metal oxide M/CaZrO₃And SiC on CH under microwave conditions₄And CO₂Catalytic reforming to produce H as the main product₂And CO, wherein M is at least one metal element of Ni and Co.

In a specific embodiment, the composite metal oxide is Ni-Co/CaZrO₃。

In a specific embodiment, the composite metal oxide M/CaZrO₃And SiC in a mass ratio of 1: (2-10).

In a specific embodiment, the catalyst is prepared by the following method:

(1) Dissolving metal nitrate in water according to a preset molar ratio, uniformly stirring, adding a precipitator to adjust the pH value to 10-12, aging, filtering and calcining to obtain the composite metal oxide, wherein the metal nitrate comprises zirconium nitrate, calcium nitrate, nickel nitrate and/or cobalt nitrate; wherein the aging time is 1-4 h, and the calcining temperature is 500-800 ℃, preferably 650-750 ℃;

(2) And (2) mixing the composite metal oxide prepared in the step (1) with SiC in proportion, and activating to obtain the catalyst.

In a specific embodiment, in the step (1), the atomic ratio of the zirconium element and the calcium element in the metal nitrate is 1: (0.2 to 20), preferably 1: (2-6); when the prepared composite metal oxide is Ni/CaZrO₃When the ratio of nickel element in the nickel nitrate to zirconium element in the zirconium nitrate is 1: (0.2 to 20), preferably 1: (2-6); when the prepared composite metal oxide is Co/CaZrO₃The atomic ratio of cobalt element in the cobalt nitrate to zirconium element in the zirconium nitrate is 1: (0.2 to 20), preferably 1: (2-6); when the prepared composite metal oxide is Ni-Co/CaZrO₃The atomic ratio of nickel element in nickel nitrate to zirconium element in zirconium nitrate is 1: (0.2 to 20), preferably 1: (2-6); the atomic ratio of cobalt element in the cobalt nitrate to nickel element in the nickel nitrate is 1: (0.2 to 10), preferably 1: (0.2-6).

In a specific embodiment, in the step (2), the activation is to heat the mixed composite metal oxide and SiC to 400-800 ℃, and H is introduced₂Reducing for 0.5-2H with the mixed gas of Ar, wherein H₂And Ar gas volume flow rate ratio of 1: (1 to 10), preferably 1: (2-5).

In one embodiment, the bed temperature of the methane dry reforming reaction is 400 to 800 ℃, preferably 650 to 800 ℃; the reaction time is 0.5-10s.

In a specific embodiment, the microwave conditions are a microwave frequency of 2.5GHz and a microwave power of 1-1400W, preferably 500-900W.

In a concrete exampleIn the embodiment, the CH₄And CO₂Is 1: (0.1 to 5), preferably 1: (0.5-1.2).

The invention also provides a catalyst for dry reforming of methane, which comprises a composite metal oxide M/CaZrO₃And SiC, wherein M is at least one metal element of Ni and Co.

The beneficial effects of the invention at least comprise:

1. the catalyst has good catalytic activity and stability when catalyzing the reforming reaction of methane and carbon dioxide under the microwave condition, when the temperature of a bed layer is controlled at 800 ℃, the conversion rate of methane can reach 96 percent, the conversion rate of carbon dioxide can reach 99.6 percent, the catalyst still keeps good activity after 600min, and the catalyst has no obvious inactivation phenomenon and high stability.

2. The catalyst can absorb microwaves and has good matching property with the microwaves, the reaction is carried out under microwave heating, the energy efficiency is high, the reaction can be carried out at a lower temperature (400-800 ℃), and the catalyst has the advantages of wide reaction temperature and low energy consumption.

3. Because the specific area of the silicon carbide is small, the active component is loaded on the silicon carbide, on one hand, the loading capacity is small, and on the other hand, the defect that the active component is easy to agglomerate exists, and the active component in the catalyst is loaded on CaZrO₃After being loaded on the carrier, the carrier is mixed with the wave-absorbing material silicon carbide in a mechanical mode, so that the defects that the loading capacity of the active component directly loaded on the silicon carbide is small and the active component is easy to agglomerate are overcome, and the carrier has better activity.

4. The catalyst is prepared by a coprecipitation method, and then is mixed with the silicon carbide in a mechanical mode, so that the process is simple, the requirement on experimental/production equipment is low, the preparation condition is easy and accurate to control, and the repeatability of the catalyst is good.

5. The nickel and the cobalt in the catalyst belong to transition metals, the cost is low compared with that of noble metals, and the catalyst prepared by the method overcomes the defect of poor stability when the transition metals are used as the catalyst through the arrangement of the carrier and a specific preparation method.

Drawings

Fig. 1 is an XRD pattern of the complex metal oxide prepared in example 1 to example 3.

FIG. 2 is a graph of the catalytic activity, i.e., the conversion of methane and carbon dioxide, as a function of time at 800 ℃ under microwave conditions for the catalyst prepared in example 1;

FIG. 3 is a graph of the catalytic activity, i.e., the conversion of methane and carbon dioxide, as a function of time at 800 ℃ under microwave conditions for the catalyst prepared in example 3;

FIG. 4 is a graph showing the catalytic activity of the catalyst prepared in comparative example 1 under microwave conditions, i.e., the conversion of methane and carbon dioxide, as a function of temperature;

FIG. 5 is a graph showing the catalytic activity of the catalyst prepared in comparative example 2 under microwave conditions, i.e., the conversion of methane and carbon dioxide, as a function of temperature;

FIG. 6 is a graph of catalytic activity at 800 deg.C, i.e., conversion of methane and carbon dioxide, as a function of temperature under conventional heating conditions for the catalyst prepared in example 3;

FIG. 7 is a graph showing the catalytic activity at 800 ℃ under the conventional heating conditions of the catalyst prepared in example 3, that is, the conversion of methane and carbon dioxide, as a function of time.

Detailed Description

The invention is described in detail below with reference to the figures and examples, but can be implemented in many different ways, which are limited and covered by the claims.

Example 1

Preparation of composite metal oxide: metal salts zirconium nitrate, calcium nitrate and nickel nitrate are weighed according to the formula and dissolved in distilled water to be uniformly stirred, wherein the mass ratio of nickel element to zirconium element to calcium element is 2:1:5, performing ultrasonic treatment for 15 minutes, heating to 50 ℃, stirring for 15min, then heating to 60 ℃, and stirring for 2h; mixing, adding sodium hydroxide as precipitant, adjusting pH to 10, stirring for 2 hr, standing, aging for 2 hr, filtering to obtain residue, oven drying at 120 deg.C in an oven, and calcining at 700 deg.C in a muffle furnace for 4 hrThen the composite metal oxide Ni/CaZrO is obtained₃。

Preparation of the catalyst: weighing 1 g of the composite metal oxide Ni/CaZrO₃And 5 grams of SiC particles were mechanically mixed; then mixing the evenly mixed composite metal oxide Ni/CaZrO₃Filling 6 g of SiC particles and the SiC particles into a quartz tube to form a catalyst bed layer, introducing Ar gas, raising the temperature to 750 ℃, and introducing Ar gas and H₂Gas mixture of gases (Ar gas and H gas in gas mixture)₂The volume ratio of gas is 4: 1) Reduction for 2 hours gave activated catalyst 1 (Ni/CaZrO)₃+SiC)。

Example 2

Preparation of composite metal oxide: weighing metal salts of zirconium nitrate, calcium nitrate and cobalt nitrate, dissolving the metal salts of zirconium nitrate, calcium nitrate and cobalt nitrate in distilled water, and uniformly stirring, wherein the mass ratio of cobalt element to zirconium element to calcium element is 2:1:5, performing ultrasonic treatment for 15 minutes, heating to 50 ℃, stirring for 15min, then heating to 60 ℃, and stirring for 2h; uniformly mixing, adding a precipitator sodium hydroxide to adjust the pH value to 10, stirring for 2h, standing and aging for 2h, filtering to obtain filter residue, placing the filter residue in an oven to dry at the drying temperature of 120 ℃, and then placing the dried filter residue in a muffle furnace at the temperature of 700 ℃ to calcine for 4h to obtain the composite metal oxide Co/CaZrO₃。

Preparation of the catalyst: weighing 1 g of the composite metal oxide Co/CaZrO₃And 5 grams of SiC particles were mechanically mixed; then mixing the uniformly mixed composite metal oxide Co/CaZrO₃Filling 6 g of SiC particles and the SiC particles into a quartz tube to form a catalyst bed layer, introducing Ar gas, raising the temperature to 750 ℃, and introducing Ar gas and H₂Gas mixture of gases (in mixture, ar gas and H gas)₂The volume ratio of gas is 4: 1) Reduction for 2 hours to give activated catalyst 2 (Co/CaZrO)₃+SiC)。

Example 3

Preparation of composite metal oxide: weighing metal salts zirconium nitrate, calcium nitrate, cobalt nitrate and nickel nitrate, dissolving the metal salts zirconium nitrate, calcium nitrate, cobalt nitrate and nickel nitrate in distilled water, and uniformly stirring, wherein the mass ratio of nickel element + cobalt element, zirconium element and calcium element is (22h; after being uniformly mixed, adding precipitator sodium hydroxide to adjust the pH value to 10, stirring for 2 hours, standing and aging for 2 hours, filtering to obtain filter residue, placing the filter residue in a drying oven to dry at the drying temperature of 120 ℃, and then placing the dried filter residue in a muffle furnace at the temperature of 700 ℃ to calcine for 4 hours to obtain the composite metal oxide Ni-Co/CaZrO₃。

Preparation of the catalyst: weighing 1 g of the composite metal oxide Ni-Co/CaZrO₃And 5 grams of SiC particles were mechanically mixed; then mixing the evenly mixed composite metal oxide Ni-Co/CaZrO₃Filling 6 g of SiC particles and SiC particles into a quartz tube to form a catalyst bed layer, introducing Ar gas, raising the temperature to 750 ℃, introducing a mixed gas of Ar gas and H2 gas (in the mixed process, the volume ratio of the Ar gas to the H2 gas is 4:1), and reducing for 2 hours to obtain the activated catalyst 3 (Ni-Co/CaZrO 2)₃+SiC)。

FIG. 1 is an XRD spectrum of the complex metal oxide prepared in examples 1 to 3, wherein three lines from bottom to top represent the complex metal oxide Ni/CaZrO, respectively₃、Co/CaZrO₃、Ni-Co/CaZrO₃From FIG. 1, it can be seen that CaZrO appears in all three catalysts₃And also diffraction peaks of Ni and/or Co oxide. However, since Ni and Co are easily oxidized in air, the catalyst reduced before the reaction cannot be tested.

In examples 1 to 3, the composite metal oxide and the silicon carbide particles were each prepared as follows: 5, in other embodiments, the mass ratio of the composite metal oxide to the silicon carbide particles is in the range of 1: (2-10) in the range of absorbing sufficient microwaves while maintaining good catalytic activity and stability.

Dry reforming reaction of methane

The experimental conditions were: the raw material gas is methane and carbon dioxide (99.9%) provided by Dalian special gas company Limited; the gas chromatography model is Agilent-7890A; the microwave power is continuously adjustable between 0 and 1400w, and the frequency is 2.5GHz; the quartz tube reactor is WG 1/2.45-phi 5.4X 54. The quartz tube used in this experiment was 540mm long and 10mm in inner diameter.

Example 4

Dry reforming reaction of methane: the catalyst 1 prepared in example 1 was filled in a quartz tube reactor to form a catalyst bed, the filling amount was 6 g, and the volume ratio of methane to carbon dioxide as feed gas was 1:1, setting the reaction temperature to be 800 ℃, setting the retention time of gas in a microwave catalytic reaction bed to be 1s, setting the reaction pressure to be normal pressure, and automatically adjusting the microwave power of a reactor to maintain the bed temperature at 800 ℃. Introducing the reacted gas into gas chromatograph for product analysis by gas sampling needle, and calculating to obtain methane (CH)₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

Examples 5 to 7

Examples 5-7 were the same as the experimental procedure of example 4, except that the bed temperature in example 4 was 800 deg.C, the bed temperature in example 5 was 650 deg.C, the bed temperature in example 6 was 700 deg.C, the bed temperature in example 7 was 750 deg.C, and the methane (CH) calculated in examples 5-7₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

Example 8

Dry reforming reaction of methane: the catalyst 1 prepared in example 2 was filled in a quartz tube reactor to form a catalyst bed, the amount of the catalyst bed was 6 g, and the volume ratio of methane to carbon dioxide as feed gas was 1:1, setting the reaction temperature to be 800 ℃, setting the retention time of gas in a microwave catalytic reaction bed to be 1s, setting the reaction pressure to be normal pressure, and automatically adjusting the microwave power of a reactor to maintain the bed temperature at 800 ℃. Introducing the reacted gas into gas chromatograph for product analysis by gas sampling needle, and calculating to obtain methane (CH)₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

Examples 9 to 11

Examples 9-11 the same experimental procedure as in example 8 was followed, except that the bed temperature in example 8 was 800 deg.C, the bed temperature in example 9 was 650 deg.C, the bed temperature in example 10 was 700 deg.C, the bed temperature in example 11 was 750 deg.C, and the methane (CH) calculated in examples 9-11₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

Example 12

Dry reforming reaction of methane: the catalyst 1 prepared in example 3 was packed in a quartz tube reactor to form a catalyst bed, the packing amount was 6 g, and the volume ratio of methane to carbon dioxide feed gas was 1:1, setting the reaction temperature to be 800 ℃, setting the retention time of gas in a microwave catalytic reaction bed to be 1s, setting the reaction pressure to be normal pressure, and automatically adjusting the microwave power of a reactor to maintain the bed temperature at 800 ℃. Introducing the reacted gas into gas chromatograph for product analysis by gas sampling needle, and calculating to obtain methane (CH)₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

Examples 13 to 15

Examples 13-15 the same experimental procedure as in example 12, except that the bed temperature in example 12 was 800 deg.C, the bed temperature in example 13 was 650 deg.C, the bed temperature in example 14 was 700 deg.C, the bed temperature in example 15 was 750 deg.C, and the methane (CH) calculated in examples 13-15 was the same as in examples 12₄) Gas and carbon dioxide (CO)₂) The conversion of the gas is detailed in table 1.

TABLE 1

As shown in Table 1, a high conversion was achieved at a catalyst bed temperature of 750 ℃ using Ni-Co/CaZrO₃The + SiC catalyst catalyzes the reforming of methane and carbon dioxide under the microwave condition, and the conversion rate of methane can reach 93.0%. Therefore, at a lower temperature, the composite metal oxide + SiC catalyst can show higher activity, and the energy consumption and the operation cost can be greatly reduced.

Examples 16-18 examination of the stability of the catalyst for microwave-catalyzed dry reforming of methane

Example 16

Substantially the same as in example 4, example 1Preparation of the resulting 6 g catalyst 1 (Ni/CaZrO)₃+ SiC) is filled in a quartz tube reactor for microwave catalytic reaction, the retention time of gas in a microwave catalytic reaction bed is 1s, the reaction pressure is normal pressure, the bed temperature is maintained at 800 ℃, different from the embodiment 4, the stability of the catalyst is examined by prolonging the catalytic reaction time of the catalyst 1, the activity of the catalyst changes along with time as shown in figure 2, and as can be seen from figure 2, the catalyst still keeps good activity after the catalytic reaction time reaches 600min, no obvious inactivation occurs, which indicates that the catalyst can keep long-time stability under the reaction atmosphere.

Example 17

The catalyst used in example 17 was the catalyst 3 (Ni-Co/CaZrO) prepared in example 3, which was substantially the same as in example 16₃+ SiC), the change of the activity of the catalyst with time is shown in figure 3, and it can be seen from figure 3 that the catalyst still maintains good activity after the catalytic reaction time reaches 600min, and no obvious deactivation phenomenon occurs, which indicates that the catalyst can maintain long-term stability in a reaction atmosphere.

Comparative example 1

Mixing the components in a mass ratio of 1: caZrO of 5₃And the mixture composed of SiC particles is filled in a quartz tube reactor to form a catalyst bed layer, the filling amount is 6 g, and the volume ratio of methane to carbon dioxide is 1:1, the residence time of the gas in the microwave catalytic reaction bed is 1s, the reaction pressure is normal pressure, the microwave power is adjusted to maintain the bed temperature at 800 ℃, and the mixture (CaZrO) is examined₃+ SiC) activity of microwave-catalyzed dry reforming of methane maintained at a bed temperature of 800 c, see in particular fig. 4.

Comparative examples 2 to 4

Comparative examples 2 to 4 were the same as in comparative example 1 except that the bed temperature of comparative example 1 was 800 deg.C, the bed temperature of comparative example 2 was 650 deg.C, the bed temperature of comparative example 3 was 700 deg.C, the bed temperature of comparative example 4 was 750 deg.C, and the CaZrO 2 mixture was examined₃+ SiC activity in the bed temperature maintained at 650 c, 700 c and 750 c respectively for microwave catalytic methane dry reforming, see in particular fig. 4.

Comparative example 5

6 g of SiC particles are filled in a quartz tube reactor to form a catalyst bed layer, and the volume ratio of methane to carbon dioxide inlet gas is 1:1, the retention time of gas in a microwave catalytic reaction bed is 1s, the reaction pressure is normal pressure, the microwave power is adjusted to maintain the bed temperature at 800 ℃, and the activity of the SiC particles in the microwave catalytic methane dry reforming is examined when the bed temperature is maintained at 800 ℃, specifically shown in figure 5.

Comparative examples 6 to 8

Comparative examples 6 to 8 were identical to the experimental procedure of comparative example 5, except that the bed temperature of comparative example 5 was 800 ℃, the bed temperature of comparative example 6 was 650 ℃, the bed temperature of comparative example 7 was 700 ℃, and the bed temperature of comparative example 8 was 750 ℃, and the activity of the SiC particles in microwave-catalyzed dry reforming of methane at bed temperatures maintained at 650 ℃, 700 ℃ and 750 ℃ respectively was examined, as shown in fig. 5.

As can be seen from FIGS. 4 and 5, the mixture (CaZrO)₃+ SiC) and SiC particles in the microwave catalytic methane dry reforming reaction, the conversion rate of methane and carbon dioxide is not less than 2%, and almost no catalytic activity exists.

Comparative examples 9 to 12

Comparative example 9 is substantially the same as example 12, comparative example 10 is substantially the same as example 13, comparative example 11 is substantially the same as example 14, and comparative example 12 is substantially the same as example 15, with the difference that the heating method is different, examples 12 to 15 are microwave heating, and comparative examples 9 to 12 are conventional tube furnace heating. The relationship between the conversion rates of methane gas and carbon dioxide gas and the temperature plotted according to the experimental data of comparative examples 9 to 12 is shown in detail in fig. 6, and the relationship between the conversion rates of methane gas and carbon dioxide gas and the catalytic reaction time of the catalyst is shown in detail in fig. 7.

As can be seen from comparing the experimental data in table 1 and fig. 6, the conversion rate of the catalyst 3 in the microwave reaction mode is significantly higher than the activity in the conventional reaction mode, for example, the conversion rates of methane and carbon dioxide in the microwave mode can reach 75.3% and 63.6% respectively at 650 ℃, while the conversion rates in the conventional mode are 45.2% and 35.3% respectively.

As can be seen from a comparison of fig. 3 and 7, the activity of the catalyst showed no change with time in the microwave mode, while it tended to decrease in the conventional mode. This indicates that the catalyst can maintain activity for a longer time in the microwave mode relative to the conventional mode.

It should be noted that the MCRM in fig. 2 to 5 represents a microwave catalytic reaction mode; CRM in fig. 6 and 7 represents a conventional reaction pattern.

It should be noted that, in the examples of the present invention, the activity of the catalyst is represented by the conversion rates of methane gas and carbon dioxide gas, and a high conversion rate represents that the activity of the catalyst is good, and a low conversion rate represents that the activity of the catalyst is poor.

Comparative example 13

Ni with the mass fraction of 9% is loaded on SiC silicon carbide particles by using an immersion method to prepare a catalyst Ni/SiC, 5g of the catalyst is filled in a quartz tube reactor to form a catalyst bed layer, and the volume ratio of methane to carbon dioxide inlet gas is 1:1, the retention time of the gas in the microwave catalytic reaction bed is 1s, the reaction pressure is normal pressure, the microwave power is adjusted to maintain the bed temperature at 800 ℃, and the conversion rate of methane and carbon dioxide in the microwave catalytic methane dry reforming reaction is calculated and shown in table 2.

Comparative examples 14 to 16

Comparative examples 14 to 16 are the same as the experimental procedure of comparative example 13 except that the bed temperature of comparative example 13 is 800 deg.c, the bed temperature of comparative example 14 is 650 deg.c, the bed temperature of comparative example 15 is 700 deg.c, the bed temperature of comparative example 16 is 750 deg.c, and the calculated conversion rates of methane and carbon dioxide at different bed temperatures are shown in table 2.

TABLE 2

As can be seen from table 2, when the catalyst Ni/SiC is used to catalyze reforming of methane gas and carbon dioxide gas under microwave conditions, the conversion rates of methane and carbon dioxide gas are lower than those of the catalyst provided in the embodiment of the present invention when the catalyst is used to perform dry reforming of methane under the same conditions.

The foregoing is a further detailed description of the present invention in connection with specific preferred embodiments thereof, and it is not intended to limit the invention to the specific embodiments thereof. For those skilled in the art to which the invention pertains, several simple deductions and substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims (7)

1. A dry reforming reaction of methane under microwave condition is characterized in that the dry reforming reaction of methane comprises a composite metal oxide Ni-Co/CaZrO₃And SiC on CH under microwave conditions₄And CO₂Catalytic reforming to produce H as the main product₂And CO, wherein the bed temperature of the dry reforming reaction of the methane is 400 to 800 ℃, and the reaction time is 0.5 to 10 s;

the catalyst is prepared by adopting the following method:

(1) Dissolving metal nitrate in water according to a preset molar ratio, uniformly stirring, adding a precipitator to adjust the pH value to 10 to 12, and aging, filtering and calcining to obtain the composite metal oxide, wherein the metal nitrate comprises zirconium nitrate, calcium nitrate, nickel nitrate and cobalt nitrate; wherein the aging time is 1 to 4 hours, and the calcining temperature is 650 to 750 ℃;

(2) And (2) mixing the composite metal oxide prepared in the step (1) with SiC in proportion, and activating to obtain the catalyst.

2. The microwave-conditioned dry methane reforming reaction according to claim 1, wherein the composite metal oxide is Ni-Co/CaZrO₃And SiC in a mass ratio of 1: (2 to 10).

3. The dry reforming reaction of methane under microwave conditions as claimed in claim 2, wherein in the step (1), the atomic ratio of zirconium element and calcium element in the metal nitrate is 1: (2~6); the atomic ratio of nickel element in nickel nitrate to zirconium element in zirconium nitrate is 1: (2~6); the atomic ratio of cobalt element in the cobalt nitrate to nickel element in the nickel nitrate is 1: (0.2 to 6).

4. The dry reforming reaction of methane under the microwave condition as claimed in claim 2, wherein in the step (2), the activation is to heat the mixed composite metal oxide and SiC to 400-800 ℃, and H is introduced into the mixture₂Reducing with Ar for 0.5 to 2h, wherein H₂And Ar gas volume flow rate ratio of 1: (2~5).

5. The dry reforming reaction of methane under microwave conditions according to any one of claims 1 to 4, characterized in that said microwave conditions are: the microwave frequency is 2.5GHz, and the microwave power is 500 to 900W.

6. The dry reforming reaction of methane under microwave conditions according to any one of claims 1 to 4, wherein said CH₄And CO₂Is 1: (0.5 to 1.2).

7. A catalyst for dry reforming reaction of methane, which is characterized by comprising a composite metal oxide Ni-Co/CaZrO₃And SiC, the catalyst is prepared by adopting the following method:

(1) Dissolving metal nitrate in water according to a preset molar ratio, uniformly stirring, adding a precipitator to adjust the pH value to 10 to 12, and aging, filtering and calcining to obtain the composite metal oxide, wherein the metal nitrate comprises zirconium nitrate, calcium nitrate, nickel nitrate and cobalt nitrate; wherein the aging time is 1 to 4 hours, and the calcining temperature is 650 to 750 ℃;

(2) And (2) mixing the composite metal oxide prepared in the step (1) with SiC in proportion, and activating to obtain the catalyst.

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