Enhanced sintering resistance of bimetal/SBA-15 catalysts with promising activity under a low temperature for CO methanation

摘要

According to its thermodynamic equilibrium analysis and strong exothermic characteristics, the major challenge of syngas methanation is to develop a high-efficient low-temperature catalyst with superior sintering resistance. In this study, bimetal-based SBA-15 catalysts were prepared via a citric acid-assisted impregnation method and applied in CO methanation. The obtained catalysts were characterized via X-ray diffraction, N-2 adsorption-desorption, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, H-2 temperature-programmed reduction and other techniques. Combining the structural characterization of the fresh and used catalyst, the function of the organic additive and metal promoters was revealed. The catalysts exhibited superior low-temperature activity and excellent sintering resistance owing to the electron migration from the additive metal to Ni, strong interaction between the metal and support and the confinement effect of the support. The catalyst with Mo as a promotor exhibited the best dispersion and the largest surface concentration of nickel, which resulted in its highest catalytic activity among the catalysts. The design and preparation of a highly effective catalyst can provide novel insight into the preparation of other catalysts.