Unveiling the Suppressive Effect of Oxygenated VOCs on Dichloromethane Catalytic Oxidation over Zeolite-Confined Ru Catalysts: Mechanism and Regulation

Deciphering competitive adsorption, interactions, and underlying mechanisms of multicomponent volatile organic compounds (VOCs) on catalysts presents a pivotal yet challenging task for the design of high-performance catalysts. This study systematically investigates the impact of coexisting nonchlorinated VOCs (e.g., acetone and benzene) on dichloromethane oxidation efficiency over the zeolite-encapsulated Ru catalysts, with a particular focus on elucidating the suppression mechanisms induced by oxygenated VOCs (OVOCs). Results indicate that the introduction of benzene or propane exerts a negligible influence on dichloromethane deep oxidation. In stark contrast, OVOCs such as acetone significantly suppress the mineralization of dichloromethane, concurrently promoting the formation of chloromethane (CH₃Cl) as a major byproduct. It was found that the increase in CH₃Cl is due to the hydrogen supply of OVOCs, which contributes 90% to the formation of CH₃Cl. Moreover, the preferentially adsorbed OVOCs compete with dichloromethane for reactive oxygen species, and the intermediate products occupy the active sites, hindering the deep oxidation of CH₃Cl. To overcome this inhibition and enhance catalytic efficiency for dual-component VOCs, a combined catalytic system (PtMn@Z-RuMn@Z) was developed. This novel configuration achieved the efficient simultaneous abatement of both OVOCs and dichloromethane, offering a viable engineering approach for practical industrial applications.