Pod-shaped supported Ni/Al2O3 catalyst, and preparation method and application thereof

Abstract

The invention belongs to the field of synthesis and catalytic application of inorganic catalytic nano materials, and in particular, relates to a pod-shaped supported Ni / Al2O3 catalyst, and a preparation method and application thereof; the preparation method of the pod-shaped supported Ni / Al2O3 catalyst comprises the following steps: step 1, dissolving water-soluble aluminum salt in water to obtainan aluminum salt solution; step 2, adding nickel hydroxide into the aluminum salt solution according to a certain molar ratio of Ni to Al, and stirring to obtain uniform mixed sol; step 3, drying themixed sol to obtain mixed xerogel; and step 4, roasting and reducing the mixed xerogel in a hydrogen atmosphere to obtain the pod-shaped Ni / Al2O3 catalyst. The pod-shaped Ni / Al2O3 catalyst prepared by the preparation method provided by the invention has high CO conversion rate and CH4 selectivity, can be continuously used for 100 h at a high temperature of 500 DEG C, has almost no attenuation ofcatalytic activity, and has excellent service life.

Description

technical field [0001] The invention belongs to the field of synthesis and catalytic application of inorganic catalytic nanomaterials, in particular to a pod-shaped supported Ni / Al 2 o 3 Catalysts, their preparation and applications. Background technique [0002] Catalytic carbon monoxide methanation to produce synthetic natural gas is an indispensable and important step in the process of coal-to-natural gas chemical technology. The development of methanation technology is not only conducive to the clean utilization of coal resources, but also more effectively guarantees the supply of natural gas, which can alleviate the problem of insufficient natural gas supply in my country to a certain extent. [0003] The process of catalytic methanation is an exothermic process. In the actual industrial production process, a large amount of heat will be released during the methanation reaction of high-concentration carbon monoxide, and the temperature of the reactor will increase gre...

AI Technical Summary

Problems solved by technology

The patent of He Dehua et al. (application number: 201010159249.9) reported a kind of Ni / Al prepared by impregnation method 2 o 3 -AlN catalyst, the method steps are cumbersome and unfavorable for large-scale preparation, and the life of the prepared catalyst is only 50h

The patent of Li Zhong et al. (application number: 201610062031.9) reported a gel method to prepare Ni / Al 2 o 3 The method of catalyzer, and added a certain amount of Yb in catalyzer 2 o 3 , La 2 o 3 , Dy 2 o 3 , Eu 2 o 3 As an additive, but the highest conversion rate of its catalyst is only 95%

Another patent (application number: 201610062034.2) by Li Zhong et al. reported a precipitation method to prepare Ni / Al 2 o 3 Catalyst method, also added a certain amount of Yb in the same catalyst 2 o 3 , La 2 o 3 , Dy 2 o 3 , Eu 2 o 3 As an auxiliary agent, but the particle size of its active component nickel is relatively large (12-16nm), and its performance as a catalyst for methanation is still unsatisfactory, and the highest conversion rate of its catalyst is only 96%.

Chen Hua's patent (application number: 201711216822.3) reported a co-precipitation method to prepare Ni / Al 2 o 3 Catalyst method, which cannot achieve high dispersion of nickel, because the precipitation constants of nickel and aluminum are very different, so it is difficult to achieve high dispersion of nickel

The above analysis shows that the currently reported Ni / Al 2 o 3 The catalyst still has the problems of cumbersome preparation methods, low efficiency, and poor catalyst activity. Combining the above analysis, a novel and simple method is used to obtain a catalyst with high dispersion, small active component particle size, and high methanation activity. Long life Ni / Al 2 o 3 Catalyst remains a big challenge

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