A nickel–molybdenum carbide-based composite catalyst enables CO2 electroreduction to syngas with an accurately adjustable CO/H2 ratio

Abstract

Herein, we report a nickel–molybdenum carbide-based composite (NIMOC) catalyst, which was prepared by physically mixing Ni/NC and MoC/NC, serving as the preferred CO evolution (PCE) unit and preferred H₂ evolution (PHE) unit, respectively, to enable efficient electrochemical CO₂ reduction reaction (eCO₂RR) to syngas with an accurately adjustable CO/H₂ ratio that satisfies the requirements of the downstream applications of syngas. It also avoids the unfavorable interaction between the dual sites of Ni for the CO evolution reaction (CER) and MoC for the H₂ evolution reaction (HER) of the supported bifunctional Ni–MoC/NC catalyst. This work not only reports the generation of an efficient eCO₂RR catalyst for syngas production but also unveils a new and promising PCEPHE composite catalyst concept for eCO₂RR to syngas with the required CO/H₂ ratio for downstream transformations, in which the PCE unit mainly facilitates eCO₂RR to CO but also allows the HER reaction to happen, whereas the PHE unit mainly catalyzes HER but also allows the eCO₂RR to CO to take place.