Electrochemical Reduction of Carbon Dioxide to Methane at Transition Metal-Doped 1T′-MX₂ Monolayers

Developing highly efficient catalysts for the electrochemical CO₂ reduction reaction (CO₂RR) to valuable chemicals through a multi-electron reaction pathway remains a challenge, which usually faces the drawbacks of high overpotential and low selectivity. Here, we designed 1T′-MoSe₂, -WS₂, and -WSe₂ (denoted as TM@MX₂) catalysts doped with 75 kinds of transition metal (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, and Au) and investigated their CO₂RR activity via first-principles screening. In our screening strategy, the stability, CO₂ adsorption, activity, and selectivity were adopted for the indicators. Among the considered candidates, Ru@WS₂ was selected as the optimal catalyst for deep CO₂ reduction to methane with the limiting potential of −0.47 V. Particularly, we found that the introductions of transition metals generate completely different products from pristine VIB transition metal dichalcogenides during CO₂RR. In addition, most TM@MX₂ catalysts favor to form HCOOH whereas Ru@WS₂, Mn@WS₂, Cr@WS₂, and Au@WSe₂ prefer to generate CH₄ as the final product.