Boosting C‐O Bond Cleavage and Reverse Water‐Gas Shift Activity via Enriched In‐Plane Sulfur Vacancies in Single‐Layer Molybdenum Disulfide

Abstract The reduction of CO 2 to CO provides a promising approach to the production of valuable chemicals through CO 2 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 MoS 2 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 MoS 2 layer number, contributing to 100 % CO selectivity over single‐layer MoS 2 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 CO 2 , 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 MoS 2 for high‐temperature CO 2 reduction through the effective manipulation of distinct vacancy sites, shedding light on their potential industrial application.