In situ grown oxygen-vacancy-rich copper oxide nanosheets on a copper foam electrode afford the selective oxidation of alcohols to value-added chemicals

• DOI: 10.1038/s42004-022-00708-1
• Publication Date: 2022-09-12T10:02:24Z
• Authors: Mustafa Khan; Asima Hameed; Abdus Samad; Talifhani Mushiana; Muhammad Imran Ab...; Asma Akhtar; Raja Shahid Ashraf; Ning Zhang; Bruno G. Pollet; Udo Schwingenschlögl; Mingming Ma
• Keywords: Electrode; Materials Science; Organic chemistry; Cu2O; 02 engineering and technology; Formation and Properties of Nanocrystals and Nanostructures; Selective Oxidation; 7. Clean energy; Article; Catalysis; Chemical engineering; Engineering; Electrolyte; Materials Chemistry; Selectivity; Copper oxide; QD1-999; Metal-Organic Frameworks; FOS: Chemical engineering; Energy; Renewable Energy, Sustainability and the Environment; Methanol; Oxide; Formate; Oxygen; Catalytic Nanomaterials; Chemistry; Physical chemistry; 13. Climate action; Alcohol oxidation; Physical Sciences; Electrocatalysis for Energy Conversion; 0210 nano-technology; Copper; Inorganic chemistry

AbstractSelective oxidation of low-molecular-weight aliphatic alcohols like methanol and ethanol into carboxylates in acid/base hybrid electrolytic cells offers reduced process operating costs for the generation of fuels and value-added chemicals, which is environmentally and economically more desirable than their full oxidation to CO2. Herein, we report the in-situ fabrication of oxygen-vacancies-rich CuO nanosheets on a copper foam (CF) via a simple ultrasonication-assisted acid-etching method. The CuO/CF monolith electrode enables efficient and selective electrooxidation of ethanol and methanol into value-added acetate and formate with ~100% selectivity. First principles calculations reveal that oxygen vacancies in CuO nanosheets efficiently regulate the surface chemistry and electronic structure, provide abundant active sites, and enhance charge transfer that facilitates the adsorption of reactant molecules on the catalyst surface. The as-prepared CuO/CF monolith electrode shows excellent stability for alcohol oxidation at current densities >200 mA·cm2 for 24 h. Moreover, the abundant oxygen vacancies significantly enhance the intrinsic indicators of the catalyst in terms of specific activity and outstanding turnover frequencies of 5.8k s−1 and 6k s−1 for acetate and formate normalized by their respective faradaic efficiencies at an applied potential of 1.82 V vs. RHE.