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. The present work will promote the explorations of VIB transition metal dichalcogenides in the area of reducing CO2 to CH4.