Impacts of SiC Carrier and Nickel Precursor of NiLa/support Catalysts for CO2 Selective Hydrogenation to Synthetic Natural Gas (SNG)

Abstract

AbstractThe porous silicon carbide (β‐SiC) carrier supported nickel‐lanthanum based catalysts (NiLa/SiC) were synthesized via incipient‐wetness impregnation by using two types of nickel salts as the precursor, for the selective hydrogenation of carbon dioxide (CO2+4H2→CH4+2H2O). The alumina supported catalysts were also prepared and tested for comparison. The samples were characterized using TEM, TPR, XRD, SEM, TG‐DTG techniques. Compared to the Al2O3 supported catalysts, the SiC supported catalysts were more resistant to sintering and carbon deposition due to the high thermal conductivity of SiC support. The relative weak metal‐support interaction on Ni nanoparticles supported on SiC carrier resulted in the easy reduction of active species during the activation process. Meanwhile, the performances of the catalysts prepared from nickel acetate were better than those of using nickel nitrate, while enhanced nickel dispersion and better reducibility of the catalyst from nickel acetate werr evidenced by TEM, TPR and XRD results. Catalytic performances exhibited that Ni−Ac‐La/SiC catalyst possessed the higher activity with 89.4 % conversion of CO2 and almost 100 % selectivity to methane with slight deactivation after 3000 min test under reaction conditions.