Revealing active edge sites induced by oriented lattice bending of Co-CeO2 nanosheets for boosting auto-exhaust soot oxidation

Herein, a series of Co x -CeO 2 nanosheet catalysts were elaborately synthesized by a one-step hydrothermal method. The CeO 2 microsphere with crossed nanosheets can improve the soot-catalyst contact efficiency and the lattice substitution of Co ions for cerium sites in CeO 2 results in the oriented lattice bending of Co-CeO 2 nanosheets for improving adsorption/activation properties of NO and O 2 . Co 2 -CeO 2 catalyst displays the highest H 2 O-tolerance activity ( T 50  = 334 °C, TOF = 1.32 h −1 ) and excellent stability during soot oxidation in the presence of H 2 O. Combined with characterizations and DFT calculations, the mechanism was proposed: the active edge sites located at the oriented lattice bending of Co-CeO 2 nanosheets can activate surface oxygen and gaseous O 2 , and active oxygen species can boost NO oxidation to NO 2 , which is a crucial step of NO x -assistant catalytic mechanism for soot oxidation. It provides a promising way for the rational design of high-performance non-noble metal catalysts for soot oxidation in practical applications.