Ni/ZrO₂Catalyst Prepared By Hydrogel Method And Its Catalytic Performance For Methanation Of Carbon Dioxide

With the development of science and technology, the level of industrialization enhanced unceasinglyand people’s living standard improved continuall. There are a series of ecological resources and environment problems appear constantly at the same time. Such as the gradual depletion of non-renewable energy resources, dramatically emission of CO2, the increasing demand for the natural gas and other clean energy, these are due to the over-exploitation and use of oil,coal and other primary energy. Therefore, one measure to reduce the emissions of CO2, increase the convention of CO2and at the same time meet the demand of natural gas is looming ahead, Thus the methanation of CO2become a hot topic in our Country.The methanation catalysts have shown bad reaction performance in the catalytic hydrogenation of carbon dioxide for methanation at low temperature generally.In order to reduce the light-off temperature of the catalysts, increase the conversion rate of CO2, simplify the process of the preparation,and save the cost of the preparation,we have used the hydrogel method to synthesize the methanation catalyst with nitrate and studied the influence of preparation conditions,content of active components and additives on the methanation reaction.In this paper, the methanation catalyst was prepard by Hydrogel method. This method is simple,with no need for adding other raw materials in the process of preparation, and no impurities would be introduced.A series of characterization measurements have been used in this study, includingXRD、H2-TPR、CO2-TPD and TEM. The results indicate that, the ZrO2support of the catalyst prepared by hydrogel method has a amorphous structure after calcination.NiO component of the catalyst has a better promoting effect in the formation of amorphous structure of the ZrO2support.And the amorphous phase would transform into a tetragonal tetragonal phase in the reduction of H2. The electron interaction between Ni and ZrO2inhibits the growth of Ni grain and crystal transformation of ZrO2.The surface of ZrO2support would form more holes because of its amorphous structure,which could promte the dispersion of Ni component by interface effect.The highest catalytic activity was obtained by heating the Ni/ZrO2catalyst to65℃under stirring,subsequently following calcination at450℃,and then treating it with reduction of H2.Under the reaction condition, V(CO2)/V(H2)=1/4,GHSV=10000h-1,P=0.5MPa,27%CO2conversion was obtained at a low temperature of200℃. The conversion of CO2reached above99%with the selectivity of CH4above92%when the reaction temperature was improved to280-320℃.