Oxide-derived copper (OD-Cu) catalysts have received widespread attention for their ability to produce energy-dense multicarbon products. Within this class of materials, nanostructured copper hydroxide (Cu(OH)2 ) has shown excellent catalytic properties, but its synthesis requires complex pre-treatment steps of the Cu surface. In this study, we have developed a simple two-step synthesis method for homogenous Cu(OH)2 nanoneedle films using a sodium persulfate pre-treatment step prior to anodization. The Cu(OH)2 nanoneedle films show drastically enhanced uniformity after the pre-treatment due to improved current distribution and can be grown over large surface areas (63 cm2 ). As a catalyst for CO2 reduction, the Cu(OH)2 favours ethylene formation, with a near total suppression of methane production. A peak faradaic efficiency (FE) of 36.5 % is found at -1.0 V vs. the reversible hydrogen electrode (RHE), and the catalyst remains stable while providing an ethylene to methane ratio of 27.8 after 6 h of reaction.
Keywords: anodization; copper hydroxide; electrochemical CO2 reduction; multicarbon reaction products; nanoneedles.
© 2022 The Authors. Published by Wiley-VCH GmbH.