Se-Incorporation Stabilizes and Activates Metastable MoS₂ for Efficient and Cost-Effective Water Gas Shift Reaction

Although the water gas shift (WGS) reaction has sparked intensive attention for the production of high-purity hydrogen, the design of cost-efficient catalysts with noble metal-like performance still remains a great challenge. Here, we successfully overcome this obstacle by using Se-incorporated MoS₂ with a 1T phase. Combining the optimized electronic structure, additional active sites from edge sites, and a sulfur vacancy based on the 1T phase, as well as the high surface ratio from the highly open structure, the optimal MoS_1.75Se_0.25 exhibits superior activity and stability compared to the conventional 2H-phase MoS₂, with poor activity, large sulfur loss, and rapid inactivation. The hydrogen production of MoS_1.75Se_0.25 is 942 μmol, which is 1.9 times higher than MoS₂ (504 μmol) and 2.8 times higher than MoSe₂ (337 μmol). Furthermore, due to the lattice stabilization via Se-incorporation, MoS_1.75Se_0.25 exhibited excellent long-term stability without obvious change in more than 10 reaction rounds. Our results demonstrate a pathway to design efficient and cost-efficient catalysts for WGS.