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

Electrochemical CO reduction reaction (CORR), which is driven by electricity generated from renewable energy sources, is a promising technology for sustainably producing carbon-based chemicals or fuels. Several CORR catalysts have been explored to date, among which copper-based electrocatalysts are the most widely known for electrochemical CORR 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 CuO/N-doped carbon demonstrates the electrochemical conversion of carbon dioxide into multiple C products (mainly formate and methanol), with a maximum Faradaic efficiency of 95% in 0.10 m KHCO 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 CuO clusters in CO adsorption and its subsequent conversion to formate and methanol via an energetically favorable formate pathway. The electrocatalyst continued to demonstrate CO reduction to valuable C products when a simulated flue gas stream containing 15% CO along with 500 ppm SO and 200 ppm NO is used as an inlet feed.