S bridging active centers coordination with oxygen vacancy of metastable blue WO3 for efficient C–C coupling and highly selective photoconversion CO2 to ethylene

• Published in: Applied catalysis. B, Environmental Vol. 340; p. 123263
• Main Authors: Xiong, Lijun, Hu, Yingjie, Wang, Yang, Dong, Wei, Zhang, Xiaoyue, Zhang, Kan, Wang, Tianyu, Shen, Jinyou, Yang, Yong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2024
• Subjects: C-C coupling; Metastable WO3; Photocatalytic CO2 conversion; W-S-W bridge; C-C coupling; W-S-W bridge; Photocatalytic CO2 conversion; Metastable WO3
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.123263

This study proposes that metastable WO3 exhibits efficient photoconversion of CO2 to ethylene (C2H4). It is found that 1) the metastable hexagonal WO3 (h-WO3) offers a suitable bandgap for CO2 reduction, and its surface oxygen vacancy can enhance the light absorption capability and promote the separation of photogenerated electron-hole pairs, simultaneously; 2) S atoms replace oxygen atoms as the bridges to connect the adjacent W atoms to form W-S-W sites are beneficial to adsorb the *CH2 intermediates. Consequently, the optimized h-WO3 nanorods integrating oxygen vacancy and sulfur doping together have achieved the C2H4 generation yield of 1121.39 μmol g−1 with the record-high yield-based selectivity of 87.6% and electron-based selectivity of 95.7% in the field of photocatalytic CO2 reduction so far. This work provides a new avenue for the realization of CO2 photoconversion to C2+ products on a single metal oxide by virtue of O vacancy and S doping synergistic utilization. [Display omitted] •A series of metastable blue S-doped Ov-WO3 photocatalysts through a one-step hydrothermal approach has been proposed.•W-S-W sites are beneficial to the adsorption and stabilization of *CH2 intermediate to facilitate C-C coupling.•The high energy surface enhanced the light absorption ability and promoted the separation of electron-hole pairs.•O vacancy and W-S-W bridge can significantly reduce the energy barrier for the rate-determining step of C2H4 production.•Ov-WO3-THU achieved the yield of 1121.39 μmol∙g-1 for C2H4 with the record-high electron-based selectivity of 95.7%.