Selective electrochemical reduction of CO2 to CO on CuO/In2O3 nanocomposites: role of oxygen vacancies

• Published in: Catalysis science & technology Vol. 9; no. 19; pp. 5339 - 5349
• Main Authors: Devi, Pinki, Malik, Karan, Arora, Ekta, Bhattacharya, Saswata, Kalendra, V, Lakshmi, K V, Verma, Anil, Singh, Jitendra P
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2019
• Subjects: Adsorption; Argon; Carbon dioxide; Carbon monoxide; Carbon sequestration; Chemical reduction; Copper; Copper oxides; Defects; Indium oxides; Mapping; Nanocomposites; Nanorods; Noble metals; Sustainable development; Vacancies
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c9cy01396b

Sequestration of carbon dioxide (CO2) through electrocatalytic reduction to produce high-value industrial precursors, such as CO, is a promising avenue for sustainable development. Copper–indium is a non-noble metal catalyst with high activity towards CO production. However, there is a lack of control of parameters which enhance the selective CO production on copper–indium oxide. Here, the role of oxygen vacancy (VO) defects in the electrochemical reduction of CO2 (ERC) to selective CO production is reported. CuO/In2O3 nanocomposites with different VO concentrations were synthesized under different synthesis environments. CuO/In2O3 nanocomposites prepared in an argon environment exhibited higher VO concentrations as compared to nanocomposites prepared in an air environment. DFT calculations demonstrated that the activation barrier decreases from 0.48 eV to 0.31 eV for the nanocomposite having a higher VO concentration, thus exhibiting a CO yield with 85% faradaic efficiency at −0.895 V vs. RHE, suggesting that VO defects serve as the active sites for CO2 adsorption. This study provides a novel route for the enhancement in selective ERC to CO by inducing the optimum concentration of VO in CuO/In2O3 nanocomposites.