A physicochemical study of samarium oxide-based catalyst for CO2 hydrogenation reaction: effect of loadings

Abstract

Catalytic reaction has been widely explored for converting carbon dioxide (CO2) to methane (CH4). A series of samarium oxide-based catalyst was screened, while the potential Ru/Mn/Sm (5:35:60)/Al2O3was further analysed due to the highest CO2conversion (92.52%) yielded at 250 oC reaction temperature via wetness impregnation method. The catalytic activity using a home-built reactor-FTIR a ratio of H2/CO24:1 displayed that the CO2conversion increased gradually due to the effectiveness of catalysts to increase hydrogenation activity. Therefore, the base loading was varied between 55% and 65% to observe the active species that contributed to higher catalytic activity. The XRD analysis revealed the presence of samarium oxide (Sm2O3) and manganese (II) oxide (MnO2) that served as active species to enhance the catalytic activity at 60% Sm-based loading. The existence of rhombohedral α-Al2O3at 55% and 65% Sm-based loading appeared to lower the catalytic activity of the catalyst due to nucleation and crystallite growth process. Next, FESEM unearth a spherical shape with 120-130 nm particle sizes. The EDX analysis displayed that all active elements were present on the catalyst surface. As conclusion, Sm-based loading did had an impact on catalytic activity and physicochemical properties.