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Dynamic Changes in the Structure, Chemical State and Catalytic Selectivity of Cu Nanocubes during CO 2 Electroreduction: Size and Support Effects
Author(s) -
Grosse Philipp,
Gao Dunfeng,
Scholten Fabian,
Sinev Ilya,
Mistry Hemma,
Roldan Cuenya Beatriz
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201802083
Subject(s) - x ray photoelectron spectroscopy , selectivity , chemical state , chemistry , catalysis , reactivity (psychology) , electrochemistry , substrate (aquarium) , carbon fibers , x ray absorption spectroscopy , chemical stability , oxidation state , absorption spectroscopy , analytical chemistry (journal) , inorganic chemistry , materials science , chemical engineering , electrode , organic chemistry , alternative medicine , oceanography , pathology , composite number , engineering , composite material , quantum mechanics , medicine , physics , geology
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 CO 2 electroreduction (CO 2 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. C 2 H 4 and ethanol) versus CH 4 . A comparison with Cu cubes supported on Cu foils revealed an enhanced morphological stability and persistence of Cu I species under CO 2 RR in the former samples. Both factors are held responsible for the higher C 2 /C 1 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 CO 2 RR selectivity.