Active site-directed tandem catalysis on CuO/VO-MnO2 for efficient and stable catalytic ozonation of S-VOCs under mild condition
Journal
Nano Today
Journal Volume
35
Pages
100944
Date Issued
2020
Author(s)
Abstract
Tandem catalysis can carry out the sequential coupling of multiple reactions in one operation, which is promising for sulfur-containing volatile organic compounds (S-VOCs) control. Herein, a tandem catalyst (CuO/VO-MnO2) consisting of well-dispersed CuO shell and oxygen vacancy-rich (VO) hollow-structured MnO2 core exhibited superior adsorption and catalytic performance under the mild condition for the elimination of CH3SH. The optimum 5CuO/VO-MnO2 can reach a significant improvement in CH3SH elimination of ∼99 % conversion over bare CuO/ pristine MnO2 at 25 ℃ under a GHSV of 60,000 mL h−1 g−1, and an almost 4-fold enhanced catalytic activity of the individual O3 with ∼99 % utilization of the applied O3 in the feed gas. The underlying tandem catalytic mechanism was in-depth identified by XPS, in situ DRIFTs and high-level computational study. The secret to the superior performance of CuO/VO-MnO2 lies in that CH3SH was preferentially chemisorbed on multivalent CuO (Cu(I)/Cu(II)), then deeply oxidized into final product of SO42−/CO32− via the catalytic ozonation by multivalent CuO and oxygen vacancies of neighbouring VO-MnO2. Attributed to the efficient electron replenishing interaction and cycling of active oxygen vacancies at the tandem reactive site of CuO/VO-MnO2 interface ([tbnd]Mn(IV) + [tbnd]Cu(II) + 2Olatt → [tbnd]Mn(II)/Mn(III) + VO + [tbnd]Cu(I) + O2), its lifetime can extend to 300 min with limited loss of activity. These findings thus open up a way to address current multiple challenges in S-VOCs control using a single hierarchical core-shell structure with tandem catalysis.
SDGs
Type
journal article