Graphene Aerogel And Co₃O₄ With Ni Catalysts For Methanation Of Carbon Dioxide

In recent years,the living demands of human beings have continuously increased,and the amount of carbon dioxide emissions has increased significantly,which has caused troubles and even disasters for current and future lives.Therefore,the conversion of carbon dioxide into valuable chemicals is imperative,and methanation is one of the most promising technologies.The technology used for methanation is divided into two types of precious metals(ruthenium,rhodium,palladium,etc.)and transition metals represented by nickel.The price of precious metals is high,and nickel-based catalysts are more preferred in some industrialized catalysts.Nickel-based catalysts have attracted much attention because of their low price and excellent activity.Supported catalysts have always been one of the key points of research in the field of catalysis.The research on the supports has never been stopped.Exploring new materials and inexpensive materials has always been the goal of scientists.Graphene materials have always been the representatives of new materials,with the advantages of large specific surface area and good thermodynamic properties.Tricobalt tetroxide is also a metal oxide material with a special electronic structure,also often used as a catalyst carrier,and its tube is less studied.Therefore,this article studies from the following two aspects.1.Using graphene oxide(GO)as the precursor,self-assembly using hydrothermal method generates graphene aerogel(GA),it usually calls three-dimensional graphene with macroporous structure.Then,the graphene aerogel is loaded with nickel to prepare a supported catalyst.The SEM,TEM and activity tests(CO2 hydrogenation to methane)of the catalyst proved that the graphene aerogel was successfully prepared and had better catalytic activity than graphene.2.Cobalt tetroxide is synthesis by hydrothermal methods used cobalt salt as precursor,for generate the tubular morphological structure.The tubular structure of cobalt tetroxide was successfully synthesized by SEM photos,and possess uniform morphology and good stability.We prepared supported catalysts load 5%,10%,and 15%Ni use the impregnation method.We tested the activity of catalysts though the hydrogenation reaction of carbon dioxide,and found that the 10%Ni/Co3O4 catalyst has the highest conversion rate for carbon dioxide and has a high selectivity for methane.Then we modified the method for prepare catalysts,use the synchronous method prepared catalysts containing 5%,10%and 15%Ni,respectively.And the reaction of hydrogenation of carbon dioxide was carried out.The experimental results showed that the 10%Ni-Co3O4 catalyst has the highest for conversion rate of carbon dioxide,also has better selectivity of methane.We also find that catalysts prepared by synchronous method is better than supported catalyst when contain with same Ni.