The catalytic mechanism of CO₂ electrochemical reduction over transition metal-modified 1T'-MoS₂ monolayers

Recently, typical transition metal disulfides (e.g. MoS₂ in the 2H phase), have attracted tremendous attentions for catalyzing CO₂ reduction reaction (CO₂RR), but the potential catalytic performance of MoS₂ in the conducting 1T' phase for CO₂RR has rarely been reported. Inspired by the high catalytic activity of low-dimensional single-atom catalysts for CO₂RR and the enhanced stability of 1T'-MoS₂ when embedded transition metals, herein, the catalytic mechanisms of transition metal-modified 1T'-MoS₂ monolayers (denoted as TM@1T'-MoS₂, where TM is 3d-5d transition metals except Y, Tc, Cd, Hg and La-Lu) in reducing CO₂ to CH₄ have been systematically investigated via the first-principles calculations. The results show that compared to pristine 1T'-MoS₂, embedding transition metals can enrich the varieties of the CO₂RR products. Among the considered catalysts, we find that Ru@1T'-MoS₂ and Pt@1T'-MoS₂ can catalyze CO₂ reduction to CH₄ and CH₃OH with acceptable limiting potentials of -0.56 and -0.73 V, respectively. Besides, Re@1T'-MoS₂ and Zn@1T'-MoS₂ are considered to be the promising catalysts for HCOOH generation with the ultralow limiting potentials of -0.13 and -0.22 V, respectively. This work will provide useful insights to guide the design of TMD-based catalysts.