Tailored engineering of intracrystalline mesopores for boosting multicomponent volatile organic compounds simultaneous deep oxidation

Developing effective catalysts for the removal of VOCs from air is crucial for mitigating air pollution. However, the catalytic performance is often constrained by mass transfer limitations due to the mismatch between the molecular dimensions of VOCs and the pore sizes of the catalysts. Herein, we report a hierarchically porous siliceous zeolite catalyst (Pt@S-1-meso) synthesized via a reversed-phase microemulsion method, featuring abundant silanol nests and mesopores to facilitate VOCs diffusion. Using o-xylene and propane as probe molecules, we demonstrate that Pt@S-1-meso exhibits superior catalytic activity toward o-xylene achieving 90 % conversion at 159 degrees C, compared to its purely microporous counterpart (Pt@S-1), which achieved 90 % conversion at 179 degrees C. Remarkably, this diffusion enhancement persisted even in the presence of smaller propane molecules. Mechanistic studies revealed that the silanol nests in Pt@S-1-meso effectively enrich o-xylene near the Pt nanoparticles and involve in the reaction pathway, promoting its catalytic degradation with a high turnover frequency of 2.34 x 10(-2) s(-1), significantly outperforming conventional microporous zeolites (1.22 x 100(-2) s(-1)). This hierarchical pore engineering provides a promising strategy for developing efficient VOC abatement catalysts by overcoming mass transfer limitations for large molecules.