Simultaneous plasma catalytic degradation of dimethyl sulfide and methyl mercaptan with reduced graphene oxide modified manganese oxide

Plasma catalysis is a promising odor elimination technology; however, the degradation mechanism of multicomponent volatile organic sulfur compounds (VOSCs) remains unclear. This study constructed a wiring tube structure catalyst by coating layered reduced graphene oxide (rGO) on manganese oxide (MnO₂) based on an electric field response improvement strategy. The surface coating of rGO on α-MnO₂ nanowires enhanced the electric field response of the catalyst and provided the sufficient adsorption site of VOSCs. 5% rGO/MnO₂ achieved 90% dimethyl sulfide (DMS) and 98% methyl mercaptan (MM) conversion at 130 J/L, effectively inhibiting the ozone escape. The charge density difference showed that an electron transport channel was established between rGO and MnO₂ surface oxygen species, improving the surface lattice oxygen activity. Combined with in situ plasma diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and density functional theory (DFT) calculations, the degradation pathway in the presence of DMS and MM in the plasma catalytic system was revealed for the first time, including the preferential adsorption of DMS, dissociation of C-S bonds, and stepwise oxidation of CH₃S* species. This work provides a new strategy for optimizing plasma catalysts and eliminating multicomponent VOSCs at room temperature.