CO2 reforming of CH4 over rare earth elements functionalized mesoporous Ni–Ln (Ln = Ce, La, Sm, Pr)–Al–O composite oxides

Abstract

A series of rare earth elements functionalized mesoporous Ni–Ln (Ln = Ce, La, Sm, Pr)–Al–O composite oxides were originally designed and facilely synthesized via one-pot evaporation induced self-assembly (EISA) strategy. These mesoporous materials with outstanding thermal stability were investigated as the catalysts for the CO2 reforming of CH4, performing excellent catalytic activities and long-term catalytic stabilities. The “confinement effect” of the mesoporous framework matrixes contributed to stabilizing the Ni nanoparticles during the process of reaction; therefore, the serious thermal sintering of the Ni nanoparticles under severe reduction and reaction conditions was suppressed to some degree, accounting for the long catalytic stability of these mesoporous catalysts. The modification of the rare earth elements (Ce, La, Sm, Pr) played crucial roles in promoting the catalytic activities and reducing the carbon deposition. Besides, the presence of the rare earth elements also significantly influenced the distribution of the carbon species deposited over the spent catalysts. Hereby, these mesoporous Ni–Ln (Ln = Ce, La, Sm, Pr)–Al–O composite oxides promised a group of novel and stable catalyst candidates for carbon dioxide reforming of methane.