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-La_0.97Ni_0.4Cr_0.6O₃, 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 CeO_2-x (Ce_surf) and bulk lattice Ce (Ce_bulk). These play a specific role in methane dry reforming, where the Ce_surf promotes CO₂ adsorption and hinders carbon deposition, while Ce_bulk induces lattice strain and Ni exsolution, key factors contributing to the high activity and stability.