Electron-Rich Ce–O–Co<sup>n+</sup> Site Boosts Propane Total Oxidation and SO<sub>2</sub> Tolerance on the Co<sub>3</sub>O<sub>4</sub> Catalyst
Yanfei Zheng, Qian Zhao, Weinuo Xu, Rui Han, Qingling Liu
Abstract
Light alkanes are widely found in industrial and vehicle exhausts, which pose a serious threat to the environment and human health. Herein, 0.05Ce–Co 3 O 4 with atomic dispersion of Ce species in the Co 3 O 4 was synthesized by a simple sol–gel method. It achieves 90% propane conversion at 186 °C, about 102 °C lower than that of the commercial Pt/Al 2 O 3 catalyst. Moreover, it showed excellent long-term stability (140 h), water resistance (5.5 vol %), and sulfur resistance stability. Combined with characterization and theoretical calculation, it was confirmed that atomically dispersed Ce is confined in the Co 3 O 4 lattice and induces an electron-rich Co site (Ce–O–Co n+ ), which enhances propane adsorption and promotes the cleavage of the C–H bond. Besides, the oxygen vacancies of the 0.05Ce–Co 3 O 4 are significantly increased, leading to a remarkable strength in the adsorption activation capacity for gaseous oxygen and oxygen species mobility, which is conducive to the deep oxidation of propane. Significantly, this unique active site also inhibits SO 2 adsorption, endowing the product with excellent SO 2 -tolerance stability. Further, the monolithic catalyst presents excellent performance against various VOCs below 300 °C and still maintains good sulfur resistance. This study provides a new clue to design efficient C–H bond activation catalysts that are attractive for practical applications.