Ce-induced synergistic effect in exsolved perovskite catalyst for highly efficient and robust methane dry reforming.

Dry reforming of methane is an effective approach to convert two major greenhouse gases, methane and carbon dioxide, into high-value syngas, used as a feedstock for bulk and fine chemical synthesis. However, catalyst deactivation and carbon deposition under harsh conditions hinder its industrialization process. Herein, we present a Ce-modified and Ni-exsolved perovskite catalyst, 0.2Ce-La0.97Ni0.4Cr0.6O3, for achieving highly efficient and robust CH4-CO2 reforming with CH4 and CO2 conversions of 87.4% and 92.9% at 800 °C, respectively. Moreover, this unique catalyst exhibits remarkable stability, maintaining its superior activity over 800 h. Characterization and density functional theory reveal that two Ce species are present: surface oxygen vacancy-moderate CeO2-x (Cesurf) and bulk lattice Ce (Cebulk). These play a specific role in methane dry reforming, where the Cesurf promotes CO2 adsorption and hinders carbon deposition, while Cebulk induces lattice strain and Ni exsolution, key factors contributing to the high activity and stability.