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Hydrogen bonding steers the product selectivity of electrocatalytic CO reduction

The product selectivity of many heterogeneous electrocatalytic processes is profoundly affected by the liquid side of the electrocatalytic interface. The electrocatalytic reduction of CO to hydrocarbons on Cu electrodes is a prototypical example of such a process. However, probing the interactions of surface-bound intermediates with their liquid reaction environment poses a formidable experimental challenge. As a result, the molecular origins of the dependence of the product selectivity on the characteristics of the electrolyte are still poorly understood. Herein, we examined the chemical and electrostatic interactions of surface-adsorbed CO with its liquid reaction environment. Using a series of quaternary alkyl ammonium cations ($methyl4N+$,$ethyl4N+$,$propyl4N+$, and$butyl4N+$), we systematically tuned the properties of this environment. With differential electrochemical mass spectrometry (DEMS), we show that ethylene is produced in the presence of$methyl4N+$and$ethyl4N+$cations, whereas this product is not synthesized in$propyl4N+$- and$butyl4N+$-containing electrolytes. Surface-enhanced infrared absorption spectroscopy more »

Authors:
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Publication Date:
NSF-PAR ID:
10091785
Journal Name:
Proceedings of the National Academy of Sciences
Page Range or eLocation-ID:
Article No. 201900761
ISSN:
0027-8424
Publisher:
Proceedings of the National Academy of Sciences
Sponsoring Org:
National Science Foundation
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