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.