Dynamic Mn–V<sub>O</sub> Associates Boosted Molecular Oxygen Activation for Benzene Combustion on Mn-Doped Mesocrystalline CeO<sub>2</sub>
Xupeng Liu, Xupeng Liu, Yanbiao Shi, Linghao Yu, Biao Zhou, Ziyue Chen, Furong Guo, Hao Li, Xiao Liu, Xiao Liu, Lizhi Zhang, Zhihui Ai
Abstract
Highly efficient molecular oxygen activation over transition metal oxides toward catalytic abatement of aromatic volatile organic compounds (AVOCs) is possible yet challenging due to the easily deactivated surface oxygen vacancy (V O ). Herein, dynamic Mn–V O associates were crafted onto the Mn-incorporated CeO 2 mesocrystal (Mn/meso-CeO 2 ) surface with Mn substituting a Ce atom through an easy-to-handle precipitation strategy. Experiments and theoretical calculation demonstrated that the asymmetric surface Mn–O–Ce configuration induced electron delivery from the low-valent Mn to adjacent Ce, destabilizing the circumambient O atoms and facilitating the formation of dynamic Mn–V O associates. Compared to pristine meso-CeO 2, the Mn/meso-CeO 2 with dynamic Mn–V O associates could efficiently activate O 2 into a superoxide radical and a peroxanion (O 2 • – and O 2 2– ) at higher reaction temperature (over 200 °C). Meanwhile, the O atom adjacent to Mn featuring substantially elevated Lewis acidity promoted the adsorption and activation of benzene. Consequently, the Mn/meso-CeO 2 catalyst exhibited a superior catalytic oxidation reactivity ( T 90 = 215 °C) toward C 6 H 6 combustion via a Langmuir–Hinshelwood mechanism. This work underlines the importance of rational design and regulation of catalytic sites over metal oxide surfaces for robust O 2 activation and durable refractory AVOC combustion.