Phase-Engineered ZrO 2 for Tuning Catalytic Oxidation of Dichloromethane Over W/ZrO 2 :Zr-Doped WO x Clusters and the Hydrolysis-Oxidation Mechanism

作者：Chensheng Tu, Hao Zhang, Xingyi Wang, Yanglong Guo, Qiguang Dai · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.4c09912 · 被引用次数：16 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Electrocatalysts for Energy Conversion

Catalytic elimination through an oxidative decomposition pathway is the most promising candidate for the purification of chlorinated volatile organic compound (CVOC) pollutants, but the complicated mechanisms and the formation pathways of hydrogenated byproducts still need to be clearly revealed. Herein, W/ZrO 2, as a structure-tunable catalyst, is used to catalytically oxidize dichloromethane (DCM) and clarify the formation pathway of monochloromethane (MCM). Crystal engineering of ZrO 2 tailors surface WO x species; practically, the predominant Zr-WO x clusters and crystalline WO 3 can be obtained on monoclinic (m-ZrO 2 ) and tetragonal (t-ZrO 2 ) phases. Surface Zr-WO x species are highly active due to their distorted structure and abundant Lewis acid sites. In situ DRIFTS reveal that H 2 O accelerates the cycle between W═O and O═W─Cl as well as replenishes consumed hydroxyls, improving the durability of W/m-ZrO 2, and thus a hydrolysis-oxidation mechanism is proposed. Moreover, a hydride transfer pathway for MCM formation as a hydrodechlorinated byproduct is identified. −OCH 2 O– as the direct hydride donor is generated by the dissociation of DCM on surface active oxygen species or hydroxyls, and then transferred to C + H 2 Cl species on Lewis acid sites to produce MCM. This work could potentially contribute to developing novel oxidative elimination strategies for CVOCs and the rational design of efficient catalysts.