A catalyst preparation method for regulating methane and carbon monoxide selectivity and its application

Abstract

The invention relates to a method for preparing a catalyst: 1) uniformly dispersing nickel salt into a polar solvent to obtain solution A with a concentration of 0.007-0.1mol / L, and dispersing the carrier TiO 2 Evenly disperse into the alkaline solution to obtain system B, mix solution A and system B evenly, age at room temperature for 12-24h, and wash until neutral; or evenly disperse nickel ions into polar solvents to obtain a concentration of 0.007-0.1mol / L of solution A, the carrier TiO 2 Evenly disperse into a polar solvent to obtain system B, and mix solution A and system B evenly; 2) then dry at 70-90°C for 12-24h, and calcinate at 350-450°C for 3-4h, that is, it is obtained. The catalyst of the invention can realize the change of selectivity by adjusting the solution environment. 2 It exhibits excellent low-temperature catalytic performance in the hydrogenation reaction, on the one hand, in CO 2 In the methanation reaction, the selectivity of methane reaches 99%, and the activity decay is small; on the other hand, it can also generate carbon monoxide with a high selectivity of 99% in the reverse water gas reaction, with strong stability.

Description

technical field

[0001] The invention belongs to the technical field of heterogeneous catalysis, and in particular relates to a catalyst, a preparation method and its application in catalyzing carbon dioxide methanation reaction and / or reverse water gas shift reaction, that is, in the reaction of hydrogenating carbon dioxide to produce methane or carbon monoxide. . Background technique

[0002] In recent years, more and more carbon dioxide has been released into the atmosphere, which has attracted worldwide attention. Recycling carbon dioxide to reduce the harmful effects of these emissions is one of the current research hotspots, as carbon dioxide can be used as a zero or even negative cost carbon feedstock. Converting renewable hydrogen and carbon dioxide into high value-added chemicals is one of the effective ways to recover carbon dioxide to provide useful fuels. Currently, the main research content is the conversion of carbon dioxide into C1 products (methanol, carbon m...

Examples

Embodiment 1

[0032] A preparation method of a catalyst, which specifically comprises the steps:

[0033] 1) Prepared by deposition-precipitation method: 0.3287 g of nickel acetate tetrahydrate was added to 70 mL of butanediol, and sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.019 mol / L. Weigh 3 g of anatase, add 26.5 mL of 0.1 mol / L ammonia water to ultrasonic for 0.5 h to promote uniform dispersion to obtain system B (the concentration of anatase in system B is 1.4 mol / L); add solution A dropwise to the solution. In system B (the volume ratio of the two is A; B=2.6), stir for 1 hour after the dropwise addition, and then age at room temperature for 24 hours. After the aging, wash with 25% ethanol solution to neutrality;

[0034] 2) Dry in an oven at 70°C for 24h, then roast in a muffle furnace at 450°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0035] 3) Before the catalyst is used, in a volume ratio of 3:2 Ar and H 2 Reduction was carried out at 45...

Embodiment 2

[0037] A preparation method of a catalyst, which specifically comprises the steps:

[0038]1) Prepared by deposition-precipitation method: 0.3287 g of nickel acetate tetrahydrate was added to 70 mL of butanediol, and sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.019 mol / L. Weigh 3 g of anatase, add 26.5 mL of 0.1 mol / L sodium carbonate solution, and sonicate for 0.5 h to promote uniform dispersion to obtain system B (the concentration of anatase in system B is 1.4 mol / L); Add dropwise to system B (the volume ratio of the two is A; B=2.6), stir for 1 hour after the dropwise addition, then age at room temperature for 24 hours, and wash with 25% ethanol solution by volume to neutrality after aging;

[0039] 2) Dry in an oven at 70°C for 24h, then roast in a muffle furnace at 450°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0040] 3) Before the catalyst is used, in Ar and H 2 (3:2, v / v) was reduced at 450 °C for 4 h in a mixed atmosphere to...

Embodiment 3

[0042] A preparation method of a catalyst, which specifically comprises the steps:

[0043] 1) Prepared by deposition-precipitation method: 0.7824 g of nickel nitrate hexahydrate in 70 mL of ethylene glycol was sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.038 mol / L. Weigh 3 g of titanium dioxide P25, add 53.8 mL of 0.2 mol / L ammonia water, and sonicate for 0.5 h to promote uniform dispersion to obtain system B (the P25 concentration in system B is 0.7 mol / L); solution A is added dropwise to system B Medium (the volume ratio of the two is A; B=1.3); after the dropwise addition, stir for 2 hours, then age at room temperature for 12 hours, and wash with 50% ethanol solution by volume after the aging to neutrality;

[0044] 2) Dry in an oven at 80°C for 12h, then roast in a muffle furnace at 400°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0045] 3) Before the catalyst is used, in Ar and H 2 (3:2, v / v) was reduced at 400 °C for 4 h in a mi...

technical field

[0001] The invention belongs to the technical field of heterogeneous catalysis, and in particular relates to a catalyst, a preparation method and its application in catalyzing carbon dioxide methanation reaction and / or reverse water gas shift reaction, that is, in the reaction of hydrogenating carbon dioxide to produce methane or carbon monoxide. . Background technique

[0002] In recent years, more and more carbon dioxide has been released into the atmosphere, which has attracted worldwide attention. Recycling carbon dioxide to reduce the harmful effects of these emissions is one of the current research hotspots, as carbon dioxide can be used as a zero or even negative cost carbon feedstock. Converting renewable hydrogen and carbon dioxide into high value-added chemicals is one of the effective ways to recover carbon dioxide to provide useful fuels. Currently, the main research content is the conversion of carbon dioxide into C1 products (methanol, carbon m...

Examples

Embodiment 1

[0032] A preparation method of a catalyst, which specifically comprises the steps:

[0033] 1) Prepared by deposition-precipitation method: 0.3287 g of nickel acetate tetrahydrate was added to 70 mL of butanediol, and sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.019 mol / L. Weigh 3 g of anatase, add 26.5 mL of 0.1 mol / L ammonia water to ultrasonic for 0.5 h to promote uniform dispersion to obtain system B (the concentration of anatase in system B is 1.4 mol / L); add solution A dropwise to the solution. In system B (the volume ratio of the two is A; B=2.6), stir for 1 hour after the dropwise addition, and then age at room temperature for 24 hours. After the aging, wash with 25% ethanol solution to neutrality;

[0034] 2) Dry in an oven at 70°C for 24h, then roast in a muffle furnace at 450°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0035] 3) Before the catalyst is used, in a volume ratio of 3:2 Ar and H 2 Reduction was carried out at 45...

Embodiment 2

[0037] A preparation method of a catalyst, which specifically comprises the steps:

[0038]1) Prepared by deposition-precipitation method: 0.3287 g of nickel acetate tetrahydrate was added to 70 mL of butanediol, and sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.019 mol / L. Weigh 3 g of anatase, add 26.5 mL of 0.1 mol / L sodium carbonate solution, and sonicate for 0.5 h to promote uniform dispersion to obtain system B (the concentration of anatase in system B is 1.4 mol / L); Add dropwise to system B (the volume ratio of the two is A; B=2.6), stir for 1 hour after the dropwise addition, then age at room temperature for 24 hours, and wash with 25% ethanol solution by volume to neutrality after aging;

[0039] 2) Dry in an oven at 70°C for 24h, then roast in a muffle furnace at 450°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0040] 3) Before the catalyst is used, in Ar and H 2 (3:2, v / v) was reduced at 450 °C for 4 h in a mixed atmosphere to...

Embodiment 3

[0042] A preparation method of a catalyst, which specifically comprises the steps:

[0043] 1) Prepared by deposition-precipitation method: 0.7824 g of nickel nitrate hexahydrate in 70 mL of ethylene glycol was sonicated for 0.5 h to obtain a homogeneous solution A with a concentration of 0.038 mol / L. Weigh 3 g of titanium dioxide P25, add 53.8 mL of 0.2 mol / L ammonia water, and sonicate for 0.5 h to promote uniform dispersion to obtain system B (the P25 concentration in system B is 0.7 mol / L); solution A is added dropwise to system B Medium (the volume ratio of the two is A; B=1.3); after the dropwise addition, stir for 2 hours, then age at room temperature for 12 hours, and wash with 50% ethanol solution by volume after the aging to neutrality;

[0044] 2) Dry in an oven at 80°C for 12h, then roast in a muffle furnace at 400°C for 3h, and cool down to obtain NiO / TiO 2 ;

[0045] 3) Before the catalyst is used, in Ar and H 2 (3:2, v / v) was reduced at 400 °C for 4 h in a mi...

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