Disentangling activity-stability trade-off in the catalytic degradation of malodorous sulfur-containing VOCs driven...

The catalytic degradation of malodorous sulfur-containing volatile organic compounds (S-VOCs), especially methanethiol (CH₃SH), faces an enormous challenge in striking a balance between activity and stability. Herein, we develop the time-tandem and spatial-extended strategy for synthesizing t-MoO₃/meso-SiO₂ nano-reactor-type catalysts and reveal the migration and transformation behaviors of both carbon and sulfur species at the mesoscopic scale to break the catalytic CH₃SH activity and stability trade-off. The dynamic evolution of active centers from initial oxygen sites and acid sites to sulfur vacancies in MoS₂ during the reaction process as well as the formation of a new dimethyl disulfide (CH₃SSCH₃) reaction pathway are identified as the main reason for the catalysts' superior activity and sulfur resistance. H₂-TPR, XPS, Raman spectroscopy and other characterizations suggested that the final deactivation is transformed from the conventional sulfide and sulfate poisoning mechanism to MoS₂ active phase destroying mechanism. Extending the micropore to mesopore also contributes to the high sulfur-resistance stability due to the greater ability to accommodate deposited elemental sulfur. Furthermore, t-MoO₃/meso-SiO₂ catalysts have confirmed the excellent performance in the catalytic degradation of dual-component thiols and CH₃SH with water vapor present in the realistic environment, also substantiating its wide application potential in the catalytic degradation of S-VOCs.