Authors (12): S. K. Matam, P. K. Sharma, E. H. Yu, C. Drivas, M. D. Khan, M. C. Wilding, N. Ramanan, D. Gianolio, M. A. Isaacs, S. Guan, P. R. Davies, C. R. A. Catlow
Themes: New Catalysts, Core DOI: 10.1039/d4cy00602j
Citations: 5
Pub type: journal-article
Pub year: 2025
Publisher: Royal Society of Chemistry (RSC)
Issue: 4
License: [{"start"=>{"date-parts"=>[[2024, 12, 2]], "date-time"=>"2024-12-02T00:00:00Z", "timestamp"=>1733097600000}, "content-version"=>"vor", "delay-in-days"=>0, "URL"=>"http://creativecommons.org/licenses/by/3.0/"}]
Publication date(s): 2025/02/21 (print) 2024/12/02 (online)
Pages: 1070-1081
Volume: 15 Issue: {"issue"=>"4", "published-print"=>{"date-parts"=>[[2025, 2, 17]]}}
Journal: Catalysis Science & Technology
URL:We present a novel operando X-ray absorption spectroscopic (XAS) flow cell, consisting of a gas chamber for CO2 and a liquid chamber for the electrolyte, to monitor electrochemical CO2 reduction (eCO2R) over a gas diffusion electrode (GDE). The feasibility of the flow cell is demonstrated by collecting XAS data (during eCO2R over Cu-GDE) in a transmission mode at the Cu K-edge. The dynamic behaviour of copper during eCO2R is captured by XAS, which is complemented by quasi in situ Raman and X-ray photoelectron spectroscopy (XPS). The linear combination analyses (LCA) of the X-ray absorption near edge structure (XANES) indicate that copper oxides are the only species present during the first 20 min of eCO2R, which was corroborated by complementary Raman and XPS. Significantly, the complementary spectroscopic data suggest that the copper composition in the bulk and on the surface Cu-GDE evolve differently at and above 30 min of eCO2R. LCA indicates that at 60 min, 77% of copper occurs as metallic Cu and the remaining 23% in the Cu(II) oxidation state, which is not evident from the XPS results that show 100% of the copper is in <2+ oxidation state. Thus, Cu(II) is probably in the bulk of Cu-GDE, as is also evident from Raman spectroscopic result. The ethylene formation correlates very well with the occurrence of copper oxides and hydroxide species in Cu-GDE. The results not only demonstrate the applicability and versatility of the operando XAS GDE flow cell, but also illustrate the unique advantages of combining XAS with complementary Raman and XPS that enables the monitoring of the catalyst structural evolution from the bulk to surface and surface-adsorbed species.
| Name | Description | Publised |
|---|---|---|
| SI for: <i>Operando</i> X-ray absorption spectroscopic flow cell for electrochemical CO<sub>2</sub> reduction: new insight into the role of copper species | Supl. data to article... | 2025 |
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