Highly efficient electro-reduction of CO2 to formic acid by nano-copperElectronic supplementary information (ESI) available: Details for confined jet mixer, morphology of CuO catalyst layers, analytical characterisation of electrolysis products and impedance spectroscopy model included. See DOI: 10.1039/c6ta04874a

• Main Authors: Gupta, Kalyani, Bersani, Marco, Darr, Jawwad A
• Format: Journal Article
• Published: 13.09.2016
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c6ta04874a

Ultra-fine copper( ii ) oxide nanoparticles were used for the electrocatalytic reduction of CO 2 to formic acid at high Faradaic efficiencies. The nanoparticles were directly synthesised via continuous hydrothermal flow synthesis (CHFS) process, which used water as a solvent and reagent. The as-prepared nanoparticles were subsequently formulated into Nafion based inks. For the electroreduction of CO 2 , the influence of Nafion fraction on the Faradaic efficiencies and overpotential (for formic acid production), was explored over a wide potential range. The highest Faradaic efficiency for formic acid production (61%) was observed with a 25 wt% Nafion fraction, at a potential of −1.4 V vs. Ag/AgCl. Some insights into the significant increase in Faradaic efficiency for the production of formic acid with the optimum Nafion content, was elucidated with electrochemical impedance spectroscopy. Ultra-fine copper( ii ) oxide nanoparticles were used for the electrocatalytic reduction of CO 2 to formic acid at high Faradaic efficiencies.