Silica-anchored cerium-magnesium supported nickel toward improved CO2 reforming of CH4

Silica derived from bagasse bottom ash significantly enhances the catalytic activity and stability of Ce, Mg, and Mg-Ce-oxide-supported nickel catalysts in CH 4 and CO 2 reforming reactions. In this work, silica-modified MgO- and CeO 2 -supported nickel catalysts were prepared by co-precipitation using bagasse-derived sodium silicate. Their catalytic performance for syngas production was subsequently evaluated in a packed-bed reactor under reforming conditions at 700°C. Among these, nickel catalyst supported on silica-modified MgO and CeO 2 (Ni-MCS) exhibited superior CH 4 and CO 2 conversions and a more favorable H 2 /CO product ratio compared to nickel catalysts supported on pure silica or unmodified MgO-CeO 2 . This enhanced performance was attributed to the incorporation of Ce and/or Mg into the silica structure, which strengthened metal–support interactions, promoted the formation of stable Ni–Mg–O solid solutions and improved nickel dispersion on the silica-modified Mg-Ce-oxide support. In the SiO 2 -modified MgO-CeO 2 support, various oxygen species—including lattice oxygen, surface-adsorbed oxygen, and surface hydroxyl groups or chemisorbed oxygen—were observed on the catalyst surface. Notably, a higher ratio of surface-adsorbed to lattice oxygen was detected, which plays a crucial role in the rapid oxidation of carbonaceous intermediates and effectively suppressed carbon deposition. Additionally, the increased medium-strength basic sites enhanced CO 2 adsorption and dissociation, promoting CO formation and supporting carbon removal during the reaction.