Dynamic Changes in the Structure, Chemical State and Catalytic Selectivity of Cu Nanocubes during CO2 Electroreduction: Size and Support Effects. (26th April 2018)

• Record Type: Journal Article
• Authors: Grosse, Philipp; Gao, Dunfeng; Scholten, Fabian; Sinev, Ilya; Mistry, Hemma; Roldan Cuenya, Beatriz
• Is Part Of: Angewandte Chemie. Volume 130:Number 21(2018)
• Page Start: 6300
• Page End: 6305
• Publication Date: 2018-04-26
• Subjects: Dichtefunktionalrechnungen -- Elektroreduktion -- Kupferwürfel -- Nanoelektrochemie -- Oberflächenchemie; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201802083
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: In situ and operando spectroscopic and microscopic methods were used to gain insight into the correlation between the structure, chemical state, and reactivity of size‐ and shape‐controlled ligand‐free Cu nanocubes during CO2 electroreduction (CO2 RR). Dynamic changes in the morphology and composition of Cu cubes supported on carbon were monitored under potential control through electrochemical atomic force microscopy, X‐ray absorption fine‐structure spectroscopy and X‐ray photoelectron spectroscopy. Under reaction conditions, the roughening of the nanocube surface, disappearance of the (100) facets, formation of pores, loss of Cu and reduction of CuO x species observed were found to lead to a suppression of the selectivity for multi‐carbon products (i.e. C2 H4 and ethanol) versus CH4 . A comparison with Cu cubes supported on Cu foils revealed an enhanced morphological stability and persistence of Cu I species under CO2 RR in the former samples. Both factors are held responsible for the higher C2 /C1 product ratio observed for the Cu cubes/Cu as compared to Cu cubes/C. Our findings highlight the importance of the structure of the active nanocatalyst but also its interaction with the underlying substrate in CO2 RR selectivity. Abstract : Kupferwürfel : Mit verschiedenen In‐situ‐ und Operando‐Spektroskopietechniken wurde die gegenseitige Abhängigkeit von Struktur, chemischem Zustand und Reaktivität für größen‐ und formgesteuerte ligandenlose Cu‐Nanowürfel in der Elektroreduktion von CO2 untersucht. Dynamische Änderungen in der Morphologie und Zusammensetzung der auf Kohlenstoff immobilisierten Cu‐Nanowürfel wurden unter Potentialkontrolle beobachtet und mit der Produktselektivität korreliert.