Zn deposited nickel silicate nanotubes as efficient CO2 methanation catalysts

Global energy demand has connected with the environment and economic concern, and this led to an intensive focus toward carbon dioxide (CO2) capture and conversion to valuable products. Chemical conversion of CO2 via hydrogenation to methane is the interesting process that meets these growing needs. The necessity of development of a low price, and active sustainable catalyst resulted in focus on utilization of Ni and SiO2 containing catalysts for CO2 to methane at mild reaction temperature. In this contribution, nickel silicate (NiSil) nanotubes sample was prepared by solvothermal process and different loadings (0.25 to 1.0 wt.%) of Zn nanoparticles were chemically deposited on the surface of NiSil nanotubes. The 0.25Zn-NiSil catalyst exhibited significant high performance with CO2 conversion greater than 90 % at 300 °C with high good stability (for 48 h). The synthesized samples were analyzed using XRD, FT-IR, TEM, DRUV–vis XPS, H2-TPR, CO2-TPD, NH3-TPD and N2 physisorption techniques. The results indicate that the synthesized nickel silicate nanotubes possess high specific surface area and pore volume and deposition of Zn loading on NiSil surface increases reducibility and number of basic sites due to interaction between Zn-NiSil. Highly dispersed Zn-NiSil species on the surface 0.25Zn-NiSil sample are the key factors for high catalytic activity in CO2 methanation.