Constructing Bridge Hydroxyl Groups on the Ru/MOx/HZSM-5 (M = W, Mo) Catalysts to Promote the Hydrolysis Oxidation of Multicomponent VOCs

Abstract

Chlorinated and oxygenated volatile organic compounds (CVOCs and OVOCs) pose a significant threat to human health. Catalytic oxidation effectively removes these pollutants, but catalyst deactivation is a challenge. Our study focused on the hydrolysis oxidation of chlorobenzene (CB) and ethyl acetate (EA) over Ru/MO_x/HZSM-5 (M = W, Mo). It was found that doping MoO_x to the catalyst increased the structural hydroxyl amount and balanced surface acidity, thus significantly improving the catalytic stability, with Ru/MoO_x/HZSM-5 exhibiting a better activity for CB and EA oxidation (T_90% = 438 and 276 °C at space velocity = 20,000 mL g^–1 h^–1, respectively). Water vapor introduction considerably promoted hydrolysis oxidation and protected the active sites from being poisoned by cumulative chlorine. The synergistic interaction of the Mo–O(H)–Al structure in Ru/MoO_x/HZSM-5 with the Si–OH–Al structure promotes the activation of H₂O to form bridging hydroxyl groups, which provide a proton-rich environment for hydrolysis oxidation. It was also found that dissociated H₂O reacted with adsorbed oxygen species to form highly active *OOH, accelerating the deep oxidation of intermediates. We believe that the present study can provide a unique strategy for the effective elimination of multicomponent VOCs under complex conditions.