Photothermal catalytic co-oxidation of toluene and acetone over core–shell structured GCS@MnO2

Abstract

Toluene and acetone are typical volatile organic compounds (VOCs) from the chemical industry, frequently coexisting in industrial waste gases and exhibiting mutual interactions during catalytic oxidation processes. This study systematically investigates the synergistic photothermal catalytic co-oxidation of toluene and acetone over core–shell-structured GCS@MnO₂ catalysts and elucidates the interaction mechanism via density functional theory (DFT) and in situ Fourier transform infrared spectroscopy (in situ FTIR) analysis. The results demonstrate that co-oxidation of toluene and acetone leads to a 2–9% increase in toluene degradation efficiency compared to its single-component oxidation at a light intensity of 540 mW cm⁻², whereas the acetone degradation efficiency decreases by 2–5% compared to its individual oxidation. This efficiency contrast stems from the combined effects of acetone's higher oxidizability and toluene's superior adsorption on GCS@MnO₂. Acetone releases heat during its degradation due to it being more readily oxidizable than toluene, thereby accelerating decomposition of toluene intermediates, while toluene adsorption preferentially occupies the catalyst active sites, inducing competitive adsorption that suppresses acetone catalytic oxidation efficiency. The reaction pathways of the two VOCs on GCS@MnO₂ are proposed through DFT and in situ FTIR analysis.