Trilayer Polymer Electrolytes Enable Carbon-Efficient CO2 to Multicarbon Product Conversion in Alkaline Electrolyzers.
Angew Chem Int Ed Engl
; : e202404110, 2024 Jun 21.
Article
em En
| MEDLINE
| ID: mdl-39031640
ABSTRACT
The electrochemical CO2 reduction reaction (CO2RR) is an appealing method for carbon utilization. Alkaline CO2 electrolyzers exhibit high CO2RR activity, low full-cell voltages, and cost-effectiveness. However, the issue of CO2 loss caused by (bi)carbonate formation leads to excessive energy consumption, rendering the process economically impractical. In this study, we propose a trilayer polymer electrolyte (TPE) comprising a perforated anion exchange membrane (PAEM) and a bipolar membrane (BPM) to facilitate alkaline CO2RR. This TPE enables the coexistence of high alkalinity near the catalyst surface and the H+ flux at the interface between the PAEM and the cation exchange layer (CEL) of the BPM, conditions favoring both CO2 reduction to multicarbon products and (bi)carbonate removal in KOH-fed membrane electrode assembly (MEA) reactors. As a result, we achieve a Faradaic efficiency (FE) of approximately 46 % for C2H4, corresponding to a C2+ FE of 64 % at 260â
mA cm-2, with a CO2-to-C2H4 single-pass conversion (SPC) of approximately 32 % at 140â
mA cm-2-nearly 1.3â
times the limiting SPC in conventional AEM-MEA electrolyzers. Furthermore, coupling CO2 reduction with formaldehyde oxidation reaction (FOR) in the TPE-MEA electrolyzer reduces the full-cell voltage to 2.3â
V at 100â
mA cm-2 without compromising the C2H4 FE.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2024
Tipo de documento:
Article