On the activity/selectivity and phase stability of thermally grown copper oxides during the electrocatalytic reduction of CO2

Velasco-Vélez, J-J; Chuang, C-H; Gao, D; Zhu, Q; Ivanov, D; Jeon, HS; Arrigo, R; Mom, RV; Stotz, E; Wu, H-L; Jones, TE; Roldan Cuenya, B; Knop-Gericke, A; Schlögl, R

Abstract

Revealing the active nature of oxide-derived copper is of key importance to understand its remarkable catalytic performance during the cathodic CO2 reduction reaction (CO2RR) to produce valuable hydrocarbons. Using advanced spectroscopy, electron microscopy, and electrochemically active surface area characterization techniques, the electronic structure and the changes in the morphology/roughness of thermally oxidized copper thin films were revealed during CO2RR. For this purpose, we developed an in situ cell for X-ray spectroscopy that could be operated accurately in the presence of gases or liquids to clarify the role of the initial thermal oxide phase and its active phase during the electrocatalytic reduction of CO2. It was found that the Cu(I) species formed during the thermal treatment are readily reduced to Cu0 during the CO2RR, whereas Cu(II) species are hardly reduced. In addition, Cu(II) oxide electrode dissolution was found to yield a porous/void structure, where the lack of electrical connection between isolated islands prohibits the CO2RR. Therefore, the active/stable phase for CO2RR is metallic copper, independent of its initial phase, with a significant change in its morphology upon its reduction yielding the formation of a rougher surface with a higher number of underco-ordinated sites. Thus, the initial thermal oxidation of copper in air controls the reaction activity/selectivity because of the changes induced in the electrode surface morphology/roughness and the presence of more undercoordinated sites during the CO2RR.

Citation

Velasco-Vélez, J., Chuang, C., Gao, D., Zhu, Q., Ivanov, D., Jeon, H., …Schlögl, R. (2020). On the activity/selectivity and phase stability of thermally grown copper oxides during the electrocatalytic reduction of CO2. ACS catalysis, 10(19), 11510-11518. https://doi.org/10.1021/acscatal.0c03484

• Journal Article Type: Article
• Online Publication Date: Sep 9, 2020
• Publication Date: Oct 2, 2020
• Deposit Date: Oct 1, 2020
• Publicly Available Date: Oct 1, 2020
• Journal: ACS Catalysis
• Publisher: American Chemical Society
• Volume: 10
• Issue: 19
• Pages: 11510-11518
• DOI: https://doi.org/10.1021/acscatal.0c03484
• Publisher URL: https://doi.org/10.1021/acscatal.0c03484
• Related Public URLs: http://pubs.acs.org/page/accacs/about.html
• Additional Information: Additional Information : ** Article version: VoR ** From Crossref via Jisc Publications Router **Journal IDs: pissn 2155-5435; eissn 2155-5435 **History: issued 22-09-2020; published_online 22-09-2020 **License for this article: starting on 22-09-2020, , http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html; Funders : Bundesministerium für Bildung und Forschung;Deutscher Akademischer Austauschdienst;Deutsche Forschungsgemeinschaft;Alexander von Humboldt-Stiftung;Ministry of Science and Technology, Taiwan;Horizon 2020 European Research Council;H2020 European Research Council; Projects : 03SF0523C-CO2EKAT;57218279;57392335;390540038;SFB 1316;unspecified;104-2112-M-032-005-MY2;105-2911-I-032-501;725915; Grant Number: 03SF0523C-CO2EKAT; Grant Number: 57218279; Grant Number: 57392335; Grant Number: 390540038; Grant Number: SFB 1316; Grant Number: 104-2112-M-032-005-MY2; Grant Number: 105-2911-I-032-501; Grant Number: 725915