Boosting C-O Bond Cleavage and Reverse Water-Gas Shift Activity via Enriched In-Plane Sulfur Vacancies in...

The reduction of CO₂ to CO provides a promising approach to the production of valuable chemicals through CO₂ utilization. However, challenges persist with the rapid deactivation and insufficient activity of catalysts. Herein, we developed a soft-hard dual-template method to synthesize layered MoS₂ using inexpensive and scalable templates, enabling facile regulation of sulfur vacancies by controlling the number of layers. The concentration of in-plane vacancies keeps increasing with the reduction of MoS₂ layer number, contributing to 100 % CO selectivity over single-layer MoS₂ and a stable performance over 300-hour reaction at 600 °C. The space-time-yield of CO reached 35.7 g_CO g_cat ^-1 h^-1, outperforming most current catalysts. Multiple characterizations and theoretical calculations revealed that in-plane sulfur vacancy sites endowed enhanced production of CO via direct dissociation of CO₂, showing an intrinsic activity of above 5.8 times higher than that of edge sulfur vacancy sites. The rate-limiting step was shifted from C-O cleavage in edge to sulfur vacancy regeneration in plane with a lower energy barrier. Our findings exemplified the specified design and synthesis of MoS₂ for high-temperature CO₂ reduction through the effective manipulation of distinct vacancy sites, shedding light on their potential industrial application.