Boosting Electrochemical Conversion of CO2 to CO in a Membrane Electrode Assembly Using Nickel–Nitrogen/Carbon Supported Nickel–Zinc Carbide Particle Catalyst

The development of efficient catalysts for CO 2 electroreduction to value added products is required to enable electrochemical CO 2 conversion technologies that will help mitigate emissions and the devastating climate change related impacts. Atomically dispersed nickel–nitrogen–carbon (Ni–N–C) catalysts are a promising alternative to precious metal (Au and Ag) catalysts for converting CO 2 to CO. However, in CO 2 electrolyzers, the performance of Ni–N–C catalysts is still lower than that of precious metal catalysts, likely due to the low concentration of catalytically active Ni–Nx/C sites that requires high catalyst loadings that lead to CO 2 mass transport limitations. Herein, a new catalyst design is developed based on a structure that comprises Ni–Nx/C active sites along with highly dense nickel zinc carbide (Ni 3 ZnC) particles─that selectively convert CO 2 into CO. In a membrane electrode assembly (MEA) based CO 2 electrolyzer, the developed catalyst demonstrated a current density of 448 mA/cm 2 and a CO 2 to CO Faradaic efficiency of >95% at 3.1 V. This promising MEA performance opens up the opportunity towards the employment of non-precious cathode materials in CO 2 electrolyzers as a competitive alternative to precious metals.