Microwave-Assisted Fabrication of Copper Oxide/N-Doped Carbon Nanocatalyst for Efficient Electrochemical CO2 Conversion to Liquid Fuels

Electrochemical CO2 reduction reaction (CO2RR), which is driven by electricity generated from renewable energy sources, is a promising technology for sustainably producing carbon-based chemicals or fuels. Several CO2RR catalysts have been explored to date, among which copper-based electrocatalysts are the most widely known for electrochemical CO2RR and are extensively studied for their ability to generate an array of products. Their low selectivity, however, hinders their possibility of being used for practical purposes. In this work, a microwave-assisted one-pot synthesized CuxO/N-doped carbon demonstrates the electrochemical conversion of carbon dioxide into multiple C-1 products (mainly formate and methanol), with a maximum Faradaic efficiency of 95% in 0.10 m KHCO3 aqueous solution at a moderately low applied potential of -0.55 V versus RHE (reversible hydrogen electrode). The in-depth theoretical study reveals the key contribution of pyridinic N-based N-doped carbon sites and Cu2O clusters in CO2 adsorption and its subsequent conversion to formate and methanol via an energetically favorable formate pathway. The electrocatalyst continued to demonstrate CO2 reduction to valuable C-1 products when a simulated flue gas stream containing 15% CO2 along with 500 ppm SOx and 200 ppm NOx is used as an inlet feed.