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Title: Electrochemical Reduction of CO 2 : A Common Acetyl Path to Ethylene, Ethanol or Acetate

Ethylene is well known as the primary product of CO2reduction at Cu electrocatalysts using zero-gap membrane electrode assembly cells with gas diffusion cathodes. Other types of Cu electrocatalysts including oxide-derived Cu, CuSn and CuSe yield relatively more C2oxygenates; however, the mechanisms for C2product selectivity are not well established. This work considers selectivity trends of Cu-P0.065, Cu-Sn0.03, and Cu2Se electrocatalysts made using a standard one pot synthesis method. Results show that Cu-P0.065electrocatalysts (Cuδ+= 0.13) retain ethylene as a primary product with relatively higher Faradaic efficiencies (FE = 43% at 350 mA cm−2) than undoped Cu electrocatalysts (FE = 31% at 350 mA cm−2) at the same current density. The primary CO2reduction product at Cu-Sn0.03(Cuδ+= 0.27) electrocatalysts shifts to ethanol (FE = 48% at 350 mA cm−2) while CO2reduction at Cu2Se (Cuδ+= 0.47) electrocatalysts favor acetate production (FE = 40% at 350 mA cm−2). Based on these results, we propose a common acetyl intermediate and a mechanism for selective formation of ethylene, ethanol or acetate based on the degree of partial positive charge (δ+) of Cu reaction sites.

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NSF-PAR ID:
10494174
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
The Electrochemical Society
Date Published:
Journal Name:
Journal of The Electrochemical Society
Volume:
171
Issue:
3
ISSN:
0013-4651
Format(s):
Medium: X Size: Article No. 034501
Size(s):
["Article No. 034501"]
Sponsoring Org:
National Science Foundation
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