Enhanced VOCs adsorption and oxidation by hydrophobic-layer-modified YMn2O5 mullite catalyst with ultralow single-atom Pt loading
Jiaqin He, Yaru Wang, Xunxun Li, Jun Xiao, Yunchong Liu, Hua Li, Najun Li, Qingfeng Xu, Dongyun Chen, Jianmei Lu
Abstract
Hydrophobic-layer-modified mullite YMn 2 O 5 catalysts with ultralow single-atom Pt loadings and three-dimensionally ordered macroporous (3DOM) structures (denoted as × wt% Pt/YMO/Ph-3DOM) were synthesized via a facile strategy and assessed for toluene oxidation. The 3DOM structure provides a large surface area, while the ultralow Pt doping (0.1 wt%) reduces catalyst costs, improves low-temperature reducibility, and provides more oxygen vacancies , which are beneficial for O 2 adsorption and activation. Surface modification with phenyltriethoxysilane significantly improves activity under wet conditions and promotes the adsorption of toluene. 0.1 wt% Pt/YMO/Ph-3DOM achieves 100% toluene oxidation at 160 °C at a WHSV of 36,000 mL g −1 h −1 under wet conditions. In-situ DRIFTS experiments were carried out to investigate the reaction mechanism. Furthermore, DFT calculations were used to investigate the adsorption and activation of O 2 , toluene, and the intermediates on the catalyst surface, providing new insight into VOC oxidation for future investigations.