Nickel-molybdenum carbide-based composite catalyst enables CO2 electroreduction to syngas with accurately adjustable CO/H2 ratio

Abstract

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