Ce-induced synergistic effect in exsolved perovskite catalyst for highly efficient and robust methane dry reforming
作者
Chencun Hao,Zhiyu Qu,Louise R. Smith,Nicholas F. Dummer,Haifeng Qi,Thomas J. A. Slater,Zhiping Zhu,Riguang Zhang,Kai Zhao,Zhiqiang Sun,Graham J. Hutchings
Abstract 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 0.97 Ni 0.4 Cr 0.6 O 3 , for achieving highly efficient and robust CH 4 -CO 2 reforming with CH 4 and CO 2 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 CO 2 adsorption and hinders carbon deposition, while Ce bulk induces lattice strain and Ni exsolution, key factors contributing to the high activity and stability.