Carbon Dioxide Methanation Performance On Ceria Supported Ni-based Catalysts

The CO₂ methanation is of great significance in alleviating the contradiction between natural gas supply and demand,alleviating the greenhouse effect,and the storage and utilization of renewable energy.Its process efficiency is closely related to the performance of the catalyst.In this paper,Ni/CeO₂ catalysts were prepared by different methods,and their CO₂ methanation performance was studied.CeO₂ prepared by pyrolysis Ce-MOF,CeO₂ prepared by precipitation method and commercial CeO₂ were used as supports to prepare Ni/CeO₂ catalysts.Among them,The Ce-MOF-derived catalyst exhibited the best CO₂ methanation performance because its smallest nickel particle size,the largest pore volume,the largest number of oxygen vacanciesand moderate basic sites.The preparation method of the Ce-MOF-derived ceria supported nickel-based catalyst was further optimized.The research results showed that the catalyst prepared by 1,3,5-Benzenetricarboxylic acid coordination one-step method was beneficial for Ni²⁺to be incorporated into the CeO₂lattice to generate more oxygen vacancies,thereby improving the low temperature activity of CO₂ methanation reaction.The catalyst prepared by 1,3,5-Benzenetricarboxylic acid coordination one-step method（Ni/CeO₂-B）exhibited excellent CO₂ methanation performance,considering the similarity between citric acid and 1,3,5-Benzenetricarboxylic acid,the catalyst prepared by citric acid complex method（Ni/CeO₂-C）was compared with Ni/CeO₂-B catalyst for CO₂ methanation.The results showed thatthe Ni/CeO₂-B catalyst exhibited better CO₂ methanation performance because its smaller nickel particle size and larger specific surface area.By adjusting the Ni loading of Ni/CeO₂-B catalyst,the relationship between Ni loading,oxygen vacancy concentration and reaction performance was explored.In addition,the CO₂ methanation performance of nickel-based catalysts supported by CeO₂,PrO_x,and ZrO₂ was investigated.It was found that the nickel-based catalysts supported on CeO₂ exhibited better CO₂methanation activity.