Interfacial Modulation Strategy for Constructing a Hydrophobic Surface on Zeolite Template Carbon to Enhance VOCs Removal in High-Humidity Coal Flue Gas

Abstract

Emissions from coal-fired or biomass power plants are often released under conditions of high-humidity, posing significant challenges to the effectiveness and durability of adsorbents and catalysts. In industrial settings, adsorbents and catalysts are often deactivated due to water presence, which can block active sites and reduce their effectiveness. Traditional hydrophobic modification methods often cover these adsorption sites, thus reducing a material’s adsorption capacity for volatile organic compounds (VOCs). In this study, we propose a mild physical blending method, incorporating hydrophobic polymer poly(divinylbenzene) (PDVB) with zeolite-templated carbon (ZTC), to regulate the local environment of ZTC for capturing VOCs under humid conditions without damaging the chemical structure of ZTC. Numerous characterization results confirm that incorporating PDVB does not affect the structure of ZTC. The hydrophobic modification increased the adsorption capacity of ZTC by 205% at 15% water content, while the water contact angle increased from 48 to 138°. Vinyl and phenyl groups in PDVB facilitated the rapid repulsion of water molecules from the surface. Molecular dynamics simulations indicated that the hydrophobic channels promoted the desorption of water molecules, and the number of escaped water molecules increased by 286%. Additionally, we propose an industrial application model for large-scale gas emissions with low-concentration VOCs under humid conditions, which enables simultaneous adsorption and desorption, thereby enhancing operational efficiency.