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 (Cu-cubes) during CO2 electroreduction (CO2RR). Dynamic changes in the morphology and composition of Cu-cubes supported on carbon were monitored under potential control via 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 CuOx species observed were found to lead to a suppression of the selectivity for multi-carbon products (i.e. C2H4 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 CO2RR. 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 CO2RR selectivity.
Comments: 31 Pages. Angewandte Chemie 2018
[v1] 2018-05-11 06:42:59
Unique-IP document downloads: 22 times
Vixra.org is a pre-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website.
Add your own feedback and questions here:
You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.