CN114749182A - Nickel-lanthanum oxide catalyst for dry reforming of methane and preparation method thereof - Google Patents

Abstract

The invention relates to a nickel-lanthanum oxide catalyst for dry reforming of methane, wherein the active component of the catalyst is metal Ni, and the carrier is La₂O₃An obvious Ni-La interface is formed between the active component and the carrier; the active component Ni accounts for 1.0-5.0 wt%, and the Ni nano-particles have the size of about 20 nm; carrier La₂O₃Weight (D)The percentage is 95.0-99.0%. Meanwhile, the invention also discloses a preparation method of the catalyst. The invention shows very high catalytic stability, thereby effectively solving the problems of high-temperature sintering and carbon deposition of active components.

Description

A kind of nickel-lanthanum oxide catalyst for methane dry reforming and preparation method thereof

technical field

The invention relates to the technical field of heterogeneous catalysis, in particular to a nickel-lanthanum oxide catalyst for dry reforming of methane and a preparation method thereof.

Background technique

Methane dry reforming is the process of simultaneously converting two very stable carbon-one molecules, CH ₄ and CO ₂ , into syngas (CO and H ₂ ). Therefore, from a theoretical perspective, this reaction is a very challenging and important research topic in carbon-chemistry. From a practical point of view, this process is not only an important process of natural gas conversion, but also the most promising way for large-scale chemical utilization of CO ₂ in industrial applications. Therefore, it has important practical significance for alleviating the energy crisis and improving the living environment of human beings.

The catalysts currently used for this reaction are classified into two categories: noble metals and non-precious metals, among which non-precious metal Ni-based catalysts are the most widely studied due to their high methane activation ability. Despite its many environmental and economic advantages, the industrial application process of Ni-based catalysts has been plagued by severe carbon deposition and sintering. Aiming at the stability of the above Ni-based catalysts, the strategies reported in the literature include changing the catalyst preparation method, the types of additives and supports, etc., so as to regulate the interaction between Ni and the support and then adjust the surface and interface state of the active component Ni species. Commonly used supports are acidic metal oxides such as Al ₂ O ₃ , ZrO ₂ , etc., inert metal oxides such as SiO ₂ , etc., and basic metal oxides MgO, La ₂ O ₃ and the like.

Among them, the rare earth metal La ₂ O ₃ supported Ni catalyst can activate CO ₂ to form an intermediate product of lanthanum carbonate oxide (La ₂ O ₃ +CO ₂ = La ₂ O ₂ CO ₃ ), thus playing the role of carbon elimination (La ₂ O ₂ CO ₃ ). + C = La ₂ O ₃ + CO) (Journal of Catalysis, 343, 2016, 208–214). Nickel-lanthanum oxide catalysts are usually prepared by impregnation method (201080012085.5) or precipitation method (202110262555.3) to support Ni on La ₂ O ₃ support, but in the reaction process, it still faces the inability of the interaction between the active component Ni and the support La ₂ O ₃ . If the catalyst is too strong, the carrier cannot eliminate carbon in time, resulting in carbon deposition of active components and separation from the surface of the carrier or growth of particles, resulting in deactivation of the catalyst.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a nickel-lanthanum oxide catalyst for dry methane reforming and a preparation method thereof, which can effectively solve the problems of high temperature sintering and carbon deposition of active components.

In order to solve the above problems, a nickel-lanthanum oxide catalyst for methane dry reforming according to the present invention is characterized in that: the active component of the catalyst is metal Ni, the carrier is La ₂ O ₃ , the active component and the carrier are There is an obvious Ni-La interface between them; the active component Ni accounts for 1.0~5.0% by weight, and the size of Ni nanoparticles is about 20 nm; the weight percentage of the carrier La ₂ O ₃ is 95.0~99.0%.

The above-mentioned method for preparing a nickel-lanthanum oxide catalyst for dry reforming of methane is characterized in that: at room temperature, an alkaline precipitant solution is added dropwise to the La salt solution, and the pH value is adjusted to 7.0 to 1.0, and the obtained The reactant was filtered and washed until the pH value of the filtrate became neutral, dried overnight and then calcined to obtain lanthanum carbonate (La ₂ O ₂ CO ₃ ) carrier; then the Ni salt solution was immersed in lanthanum carbonate (La ₂ O ₂ CO 3 ) ₃ ) On the carrier, drying overnight, calcining and reducing in sequence, the nickel-lanthanum oxide catalyst is obtained.

The La salt solution refers to dissolving the La salt in deionized water to obtain a mixed solution with a concentration of 0.15 to 0.30 ^mol·L ; the La salt is any one of lanthanum nitrate, lanthanum acetate, and lanthanum chloride or a combination of two or more.

The alkaline precipitating agent solution refers to dissolving the alkaline precipitating agent in deionized water to obtain a mixed solution with a concentration of 0.5 to 2.0 mol·L ⁻¹ ; the alkaline precipitating agent is NH ₄ HCO ₃ , (NH _{4 )} ) ₂ CO ₃ and NH ₃ ·H ₂ O in one or a combination of two or more.

The Ni salt solution refers to that the Ni salt is dissolved in deionized water to obtain a mixed solution with a concentration of 0.07 to 0.38 mol·L ^-1 ; the Ni salt is a mixture of nickel nitrate, nickel acetate, nickel chloride, and nickel sulfate. Any one or a combination of two or more.

The mass ratio of the Ni salt to the lanthanum oxide carbonate (La ₂ O ₂ CO ₃ ) carrier in the Ni salt solution is 0.04-0.24:1.

The temperature of the drying overnight was 120°C.

The carrier roasting conditions refer to a temperature of 600° C. and a time of 2.0-4.0 h.

The conditions for calcining the catalyst refer to a temperature of 600-800° C. and a time of 2.0 h.

The reduction conditions refer to reduction at 650-900° C. for 2.0 h in an H ₂ /N ₂ atmosphere with a volume ratio of 1:2.

The above-mentioned application of a nickel-lanthanum oxide catalyst for methane dry reforming in methane dry reforming is characterized in that: under normal pressure conditions, CH ₄ and CO ₂ are continuously fed into a chamber containing the nickel - In the reaction furnace of lanthanum oxide catalyst, the reaction is carried out under the conditions of a temperature of 650~850°C and a space velocity of 15000~60000 h ^-1 to generate CO and H ₂ .

Compared with the prior art, the present invention has the following advantages:

1. Usually, the nickel-lanthanum oxide catalyst is prepared by directly loading Ni on the La ₂ O ₃ carrier. Due to the weak interaction between the active component Ni and the carrier La ₂ O ₃ , after a long time of methane dry reforming reaction After showing decreased _CH4 and _CO2 conversion, the phenomenon of gradual deactivation appeared. In the nickel-lanthanum oxide catalyst of the present invention, Ni is supported on the La ₂ O ₂ CO ₃ carrier, and the reaction can occur during the calcination of the catalyst 2La ₂ O ₂ CO ₃ (s)+ NiO(s) = La ₂ O ₃ (s ) + La ₂ NiO ₄ (s) + 2CO ₂ (g), the Ni-La interface with strong interaction can be generated in situ by further reduction, and the generated CO ₂ gas can play a role in pore expansion and increase the catalyst's capacity than the surface.

2. Usually, the Ni-based catalyst has a relatively high content of active components (Ni content> 5%), while the nickel-lanthanum oxide catalyst in the present invention has a Ni active component weight percentage of 1.0 to 5.0%. The higher reactivity can be obtained by controlling the lower Ni content, which has the advantages of simple preparation method and low production cost.

3. The nickel-lanthanum oxide catalyst prepared by using La ₂ O ₂ CO ₃ as the carrier precursor of the present invention has an obvious Ni-La interface, and the catalyst is used in the reaction of dry reforming methane to syngas, under the condition of no dilution gas. When the reaction temperature is 750 °C, the life of the catalyst is as long as 300 h without deactivation, showing very high catalytic stability, which effectively solves the problems of high temperature sintering and carbon deposition of active components.

Description of drawings

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Figure 1 is a TEM image (a) and an HRTEM image (b) of a nickel-lanthanum oxide catalyst prepared in Example 1 of the present invention.

Figure 2 is a TEM image (a) and an HRTEM image (b) of a nickel-lanthanum oxide catalyst prepared in Example 2 of the present invention.

Detailed ways

A nickel-lanthanum oxide catalyst for methane dry reforming, the active component of the catalyst is metal Ni, the carrier is La ₂ O ₃ , and there is an obvious Ni-La interface between the active component and the carrier; the active component Ni accounts for The weight percentage is 1.0-5.0%, the size of Ni nanoparticles is about 20 nm; the weight percentage of the carrier La ₂ O ₃ is 95.0-99.0%.

Its preparation method: drop an alkaline precipitant solution into La salt solution at room temperature, adjust the pH value to 7.0~1.0, the obtained reactant is filtered and washed until the pH value of the filtrate becomes neutral, first dried at 120 °C overnight, and then placed in a horse. The lanthanum oxide (La ₂ O ₂ CO ₃ ) carrier was obtained by calcining at 600 °C for 2.0~4.0 h in a Furnace; then the Ni salt solution was impregnated onto the lanthanum oxide (La 2 O 2 CO 3 ) carrier, and the lanthanum oxide (La ₂ O ₂ CO ₃ ) carrier was then heated at 120 ° C in turn. After drying overnight, calcining at 600-800 ℃ for 2.0 h in a muffle furnace, and reducing at 650-900 ℃ for 2.0 h in a tube furnace under H ₂ /N ₂ (volume ratio 1:2) atmosphere, the nickel-lanthanum oxide catalyst was obtained.

Wherein: La salt solution refers to dissolving La salt in deionized water to obtain a mixed solution with a concentration of 0.15~0.30 mol·L ^-1 ; La salt is any one or two of lanthanum nitrate, lanthanum acetate, and lanthanum chloride. more than one combination.

The alkaline precipitant solution refers to dissolving the alkaline precipitant in deionized water to obtain a mixed solution with a concentration of 0.5~2.0 mol·L ^-1 ; the alkaline precipitant is NH ₄ HCO ₃ , (NH ₄ ) ₂ CO ₃ One or a combination of two or more of NH ₃ ·H ₂ O.

Ni salt solution refers to dissolving Ni salt in deionized water to obtain a mixed solution with a concentration of 0.07~0.38 mol·L ^-1 ; Ni salt is any one of nickel nitrate, nickel acetate, nickel chloride, and nickel sulfate or combination of two or more.

The mass ratio (g/g) of Ni salt to lanthanum oxide carbonate (La ₂ O ₂ CO ₃ ) carrier in the Ni salt solution is 0.04-0.24:1.

The application of the nickel-lanthanum oxide catalyst in the dry reforming of methane: under normal pressure conditions, CH ₄ and CO ₂ are continuously fed into the reaction furnace equipped with the nickel-lanthanum oxide catalyst, and the temperature is 650~850 ℃ , the reaction is carried out under the condition of space velocity of 15000~60000 h ^-1 to generate CO and H ₂ .

Example 1

Carrier preparation: Dissolve 13 g La(NO ₃ ) ₃ ·6H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 1.0 mol·L ^-1 NH ₄ HCO ₃ to precipitate The pH of the mixed slurry was adjusted to 8.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 2.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under the irradiation of an infrared lamp, and 0.30 g of Ni(NO ₃ ) ₂ ·6H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to the crucible, and immersed while stirring. After the solvent was evaporated to dryness, it was dried in an oven at 120 °C overnight, calcined in a muffle furnace at 750 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio 1 : 2) Ni-La ₂ O ₃ catalyst was obtained by reducing at 750 ℃ for 2.0 h in the atmosphere, in which the weight percentage of Ni was 2.0%. The TEM and HRTEM images of the Ni-La ₂ O ₃ catalyst obtained in this example are shown in Figure 1. It can be seen from Figure 1 that the size of Ni nanoparticles is about 20 nm, the particle size distribution is uniform, and there is obvious Ni-La _{2 O3} interface.

Example 2

Carrier preparation: Dissolve 24 g La(CH ₃ COO) ₃ ·5H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 0.5 mol·L ^-1 NH ₃ ·H ₂ O precipitant adjusts the pH of the mixed slurry to 8.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 3.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under infrared light irradiation, and 0.40 g of Ni(CH ₃ COO) ₂ ·4H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to the crucible, and immersed while stirring. After the solvent was evaporated to dryness, it was dried in an oven at 120 °C overnight, calcined in a muffle furnace at 800 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio). 1:2) Ni-La ₂ O ₃ catalyst was obtained by reduction at 650 °C for 2.0 h in an atmosphere, in which the weight percentage of Ni was 3.0%. The TEM and HRTEM images of the Ni-La ₂ O ₃ catalyst obtained in this example are shown in Figure 2. It can be seen from Figure 2 that the size of the Ni nanoparticles is about 20 nm, the particle size distribution is uniform, and the Ni-La _{2 O3} interface.

Example 3

Carrier preparation: Dissolve 10 g LaCl ₃ in 200 mL water with stirring at room temperature (about 25°C) in a 1 L beaker, and then add dropwise 2.0 mol·L ^-1 (NH ₄ ) ₂ CO ₃ precipitant to adjust the mixed slurry pH to 9.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 4.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under the irradiation of an infrared lamp, and 0.43 g of NiCl ₂ ·6H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to Put it into a crucible, immerse it while stirring, and after the solvent is evaporated to dryness, dry it in an oven at 120 °C overnight, calcinate it in a muffle furnace at 600 °C for 2.0 h, and in a tube furnace H ₂ /N ₂ (volume ratio 1:2) atmosphere The Ni-La ₂ O ₃ catalyst was obtained by reduction at 800 °C for 2.0 h, in which the weight percentage of Ni was 4.0%.

Example 4

Carrier preparation: Dissolve 13 g La(NO ₃ ) ₃ ·6H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 1.0 mol·L ^-1 NH ₄ HCO ₃ to precipitate The pH of the mixed slurry was adjusted to 7.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 2.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under the irradiation of an infrared lamp, and 0.70 g of NiSO ₄ ·6H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to Put it into a crucible, immerse it while stirring, and after the solvent is evaporated to dryness, it is dried in an oven at 120 °C overnight, calcined in a muffle furnace at 650 °C for 2.0 h, and in a tube furnace H ₂ /N ₂ (volume ratio 1:2) atmosphere The Ni-La ₂ O ₃ catalyst was obtained by reduction at 700 °C for 2.0 h, in which the weight percentage of Ni was 5.0%.

Example 5

Carrier preparation: Dissolve 13 g La(NO ₃ ) ₃ ·6H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 1.0 mol·L ^-1 NH ₄ HCO ₃ to precipitate The pH of the mixed slurry was adjusted to 10.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 3.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under infrared light irradiation, and 0.40 g of Ni(NO ₃ ) ₂ ·6H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to the crucible, immersed while stirring, and after the solvent was evaporated to dryness, it was dried in an oven at 120 °C overnight, calcined in a muffle furnace at 700 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio 1). : 2) Ni-La ₂ O ₃ catalyst was obtained by reducing at 900 ℃ for 2.0 h in the atmosphere, in which the weight percentage of Ni was 2.5%.

Example 6

Carrier preparation: Dissolve 13 g La(NO ₃ ) ₃ ·6H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 1.0 mol·L ^-1 NH ₄ HCO ₃ to precipitate The pH of the mixed slurry was adjusted to 8.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 600 °C for 3.0 h to obtain the catalyst carrier La ₂ O ₂ CO ₃ ;

Catalyst preparation: 3.0 g of the above-mentioned La ₂ O ₂ CO ₃ carrier was added to a 50 mL crucible under the irradiation of an infrared lamp, and 0.12 g of Ni(CH ₃ COO) ₂ ·4H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution was added to the crucible, and immersed while stirring. After the solvent was evaporated to dryness, it was dried in an oven at 120 °C overnight, calcined in a muffle furnace at 750 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio). 1:2) Ni-La ₂ O ₃ catalyst was obtained by reducing at 850 °C for 2.0 h in an atmosphere, in which the weight percentage of Ni was 1.0%.

Comparative Example 1

Carrier preparation: Dissolve 13 g La(NO ₃ ) ₃ ·6H ₂ O in 200 mL of water at room temperature (about 25°C) in a 1 L beaker with stirring, and then dropwise add 1.0 mol·L ^-1 NH ₄ HCO ₃ to precipitate The pH of the mixed slurry was adjusted to 8.0. After stirring for 0.5 h, the reactant was filtered and washed until the pH of the filtrate was 7.0, dried in an oven at 120 °C overnight, and finally calcined in a muffle furnace at 800 °C for 3.0 h to obtain the catalyst carrier La ₂ O ₃ .

Catalyst preparation: 3.0 g of the above La ₂ O ₃ carrier was added to a 50 mL crucible under infrared light irradiation, and 0.24 g of Ni(NO ₃ ) ₂ ·6H ₂ O was weighed and dissolved in 7 mL of water to obtain a precursor solution. The precursor solution Add it to the crucible, and immerse it while stirring. After the solvent is evaporated to dryness, it is dried in an oven at 120 °C overnight, calcined in a muffle furnace at 800 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio 1:2) The Ni-La ₂ O ₃ catalyst was obtained by reducing at 750 ℃ for 2.0 h in the atmosphere, in which the weight percentage of Ni was 2.0%.

Comparative example 2 (this example is a catalyst prepared by a comparative co-precipitation method)

In a 1 L beaker, 15 g La(NO ₃ ) ₃ ·6H ₂ O and 1.10 g Ni(NO ₃ ) ₂ ·6H ₂ O were stirred and dissolved in 200 mL of water at room temperature (about 25℃), and then 1.0 mol·L ^-1 NH ₄ HCO ₃ precipitant adjusts the pH of the mixed slurry to 8.0. After continuing to stir for 0.5 h, the reactant was filtered and washed until the pH value of the filtrate was 7.0, dried in an oven at 120 °C overnight, calcined in a muffle furnace at 600 °C for 2.0 h, and heated in a tube furnace with H ₂ /N ₂ (volume ratio 1 : 2) Ni-La ₂ O ₃ catalyst was obtained by reducing at 750 ℃ for 2.0 h in the atmosphere, in which the weight percentage of Ni was 2.0%.

Application example 1

The nickel-lanthanum oxide catalysts prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were used for the methane dry reforming reaction, and the specific reaction conditions were: the fixed-bed quartz tube reactor was charged with 0.1 g of the calcined catalyst under normal pressure. , and diluted with 0.35 g of quartz sand. First, the catalyst is subjected to reduction treatment, and the specific operation is shown in the above examples and comparative examples. After the reduction process was over, the reaction temperature was adjusted and the gas was switched to N ₂ for purging for 0.5 h, then CH ₄ and CO ₂ (volume ratio of 1:1) were introduced for the reaction, and the products were analyzed online by gas chromatography. The test results when the reaction was carried out for 1.0 h are shown in Table 1.

Table 1 Results of dry methane reforming performance of nickel-lanthanum oxide catalysts prepared in Examples 1-6 and Comparative Examples 1-2

As can be seen from Table 1, the nickel-lanthanum oxide catalyst prepared by the method of the present invention exhibits higher CH ₄ conversion rate, CO ₂ conversion rate and H ₂ / Compared with the nickel-lanthanum oxide catalyst prepared by the precipitation method, the nickel-lanthanum oxide catalyst prepared by the method of the invention has higher activity.

Application example 2

The nickel-lanthanum oxide catalysts prepared in Example 1 and Comparative Example 1 were used in the methane dry reforming reaction, and the specific reaction conditions were: a fixed-bed quartz tube reactor under normal pressure was charged with 0.1 g of the calcined catalyst, and 0.35 g of quartz was used. Sand dilution. First, the catalyst is subjected to reduction treatment, and the specific operation is shown in the above examples and comparative examples. After the reduction process is over, adjust the reaction temperature to 750 °C, and switch the gas to N ₂ for purging for 0.5 h at the same time, and then pass CH ₄ and CO ₂ (volume ratio of 1:1) to carry out the reaction, and the raw material space velocity is 30000 mL ·g ^-1 ·h ^-1 , the product was analyzed online by gas chromatography. The catalyst stability test results are shown in Table 2.

Table 2 The test results of methane dry reforming stability of the nickel-lanthanum oxide catalysts prepared in Example 1 and Comparative Example 1

As can be seen from Table 2, the catalyst prepared by the method of the present invention has no obvious decrease in the conversion rate of CH ₄ and CO ₂ after the reaction for 300 h, and the amount of carbon deposition is greatly reduced. Therefore, the catalyst prepared by the method of the present invention has good performance. Catalytic stability of methane dry reforming.

In addition, the inventors of the present application also carried out tests with other raw materials and conditions listed in this specification with reference to the methods of Examples 1 to 6, and also obtained nickel with high methane dry reforming activity and good stability. - Lanthanum oxide catalyst. At the same time, referring to Application Examples 1-2, the above-mentioned catalyst was also used to produce synthesis gas.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus.

It should be understood that the above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement it accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

Claims (10)

1. A nickel-lanthanum oxide catalyst for dry reforming of methane, characterized by: the active component of the catalyst is metal Ni, and the carrier is La₂O₃An obvious Ni-La interface is formed between the active component and the carrier; the active component Ni accounts for 1.0-5.0 wt%, and the Ni nano-particles have the size of about 20 nm; carrier La₂O₃The weight percentage is 95.0-99.0%.

2. The method of claim 1 for preparing a nickel-lanthanum oxide catalyst for dry reforming of methane, wherein: dropwise adding an alkaline precipitator solution into the La salt solution at room temperature, adjusting the pH value to 7.0-1.0, filtering and washing the obtained reactant until the pH value of the filtrate is neutral, drying overnight, and then roasting to obtain a lanthanum carbonate oxide carrier; then soaking Ni salt solution on lanthanum carbonate oxide carrier, drying overnight, roasting, reducing to obtain the nickel-lanthanum oxide catalyst.

3. The method of claim 2, wherein the nickel-lanthanum oxide catalyst is prepared by a method comprising: the La salt solution is prepared by dissolving La salt in deionized water to obtain the solution with the concentration of 0.15-0.30 mol.L^-1The mixed solution of (1); the La salt is any one or the combination of more than two of lanthanum nitrate, lanthanum acetate and lanthanum chloride.

4. The method of claim 2 for preparing a nickel-lanthanum oxide catalyst for dry reforming of methane, comprising: the alkaline precipitant solution is prepared by dissolving an alkaline precipitant in deionized water to obtain a solution with a concentration of 0.5-2.0 mol.L^-1The mixed solution of (1); the alkaline precipitator is NH₄HCO₃、(NH₄)₂CO₃And NH₃·H₂O, or a combination of two or more thereof.

5. The method of claim 2, wherein the nickel-lanthanum oxide catalyst is prepared by a dry reforming methodThe method comprises the following steps: the Ni salt solution is prepared by dissolving Ni salt in deionized water to obtain the Ni salt solution with the concentration of 0.07-0.38 mol.L^-1The mixed solution of (1); the Ni salt is any one or the combination of more than two of nickel nitrate, nickel acetate, nickel chloride and nickel sulfate.

6. The method of claim 2, wherein the nickel-lanthanum oxide catalyst is prepared by a method comprising: the mass ratio of the Ni salt in the Ni salt solution to the lanthanum oxycarbonate carrier is 0.04-0.24: 1.

7. the method of claim 2, wherein the nickel-lanthanum oxide catalyst is prepared by a method comprising: the roasting condition of the carrier is that the temperature is 600 ℃ and the time is 2.0-4.0 h.

8. The method of claim 2, wherein the nickel-lanthanum oxide catalyst is prepared by a method comprising: the roasting condition of the catalyst is that the temperature is 600-800 ℃ and the time is 2.0 h.

9. The method of claim 2 for preparing a nickel-lanthanum oxide catalyst for dry reforming of methane, comprising: the reduction conditions refer to the volume ratio of 1: 2H₂/N₂Reducing for 2.0 h at 650-900 ℃ under the atmosphere.

10. The use of a nickel-lanthanum oxide catalyst for dry reforming of methane as claimed in claim 1 in dry reforming of methane, wherein: under normal pressure, adding CH₄And CO₂Continuously introducing the mixture into a reaction furnace filled with the nickel-lanthanum oxide catalyst, and keeping the temperature at 650-850 ℃ and the space velocity at 15000-60000 h^-1Under the conditions of (1) to produce CO and H₂。

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