Revealing the active phase of copper during the electroreduction of CO2 in aqueous electrolyte by correlating in situ x-ray spectroscopy and in situ electron microscopy

Velasco-Velez, J-J; Mom, RV; Sandoval-Diaz, L-E; Falling, LJ; Chuang, C-H; Gao, D; Jones, TE; Zhu, Q; Arrigo, R; Roldan Cuenya, B; Knop-Gericke, A; Lunkenbein, T; Schlögl, R

Abstract

The variation in the morphology and electronic structure of copper during the electroreduction of CO2 into valuable hydrocarbons and alcohols was revealed by combining in situ surface- and bulk-sensitive X-ray spectroscopies with electrochemical scanning electron microscopy. These experiments proved that the electrified interface surface and near-surface are dominated by reduced copper. The selectivity to the formation of the key C–C bond is enhanced at higher cathodic potentials as a consequence of increased copper metallicity. In addition, the reduction of the copper oxide electrode and oxygen loss in the lattice reconstructs the electrode to yield a rougher surface with more uncoordinated sites, which controls the dissociation barrier of water and CO2. Thus, according to these results, copper oxide species can only be stabilized kinetically under CO2 reduction reaction conditions.

• Journal Article Type: Article
• Acceptance Date: May 27, 2020
• Online Publication Date: May 27, 2020
• Publication Date: Jun 12, 2020
• Deposit Date: Jun 12, 2020
• Publicly Available Date: Jun 12, 2020
• Journal: ACS Energy Letters
• Electronic ISSN: 2380-8195
• Publisher: American Chemical Society
• Volume: 5
• Issue: 6
• Pages: 2106-2111
• DOI: https://doi.org/10.1021/acsenergylett.0c00802
• Publisher URL: https://dx.doi.org/10.1021/acsenergylett.0c00802
• Related Public URLs: http://pubs.acs.org/journal/aelccp
• Additional Information: Additional Information : ** Article version: VoR ** From Crossref via Jisc Publications Router **Journal IDs: pissn 2380-8195; eissn 2380-8195 **History: issued 03-06-2020; published_online 03-06-2020 **License for this article: starting on 03-06-2020, , http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html; Funders : German Academic Exchange Service (DAAD);German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF);European Research Council (ERC); Grant Number: #03SF0523C-“CO2EKAT” and #033RCOO4D-“e-Ethylene”; Grant Number: ERC-725915, OPERANDOCAT