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Correlating Oxidation State and Surface Area to Activity from Operando Studies of Copper CO Electroreduction Catalysts in a Gas-fed Device

Lee, Soo Hong and Sullivan, Ian and Larson, David M. and Liu, Guiji and Toma, Francesca M. and Xiang, Chengxiang and Drisdell, Walter S. (2020) Correlating Oxidation State and Surface Area to Activity from Operando Studies of Copper CO Electroreduction Catalysts in a Gas-fed Device. ACS Catalysis, 10 (14). pp. 8000-8011. ISSN 2155-5435. https://resolver.caltech.edu/CaltechAUTHORS:20200626-103612366

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Abstract

The rational design of high-performance electrocatalysts requires a detailed understanding of dynamic changes in catalyst properties, including oxidation states, surface area, and morphology under realistic working conditions. Oxide-derived Cu catalysts exhibit a remarkable selectivity toward multicarbon products for the electrochemical CO reduction reaction (CORR), but the exact role of the oxide remains elusive for explaining the performance enhancements. Here, we used operando X-ray absorption spectroscopy (XAS) coupled with simultaneous measurements of the catalyst activity and selectivity by gas chromatography (GC) to study the relationship between oxidation states of Cu-based catalysts and the activity for ethylene (C₂H₄) production in a CO gas-fed cell. By utilizing a custom-built XAS cell, oxidation states of Cu catalysts can be probed in device-relevant settings and under high current densities (>80 mA cm⁻²) for the CORR. By employing an electrochemical oxidation process, we found that the Cu oxidation states and specific ion species do not correlate with C₂H₄ production. The difference in the CORR activity is also investigated in relation to electrochemical surface area (ECSA) changes. While the hydrogen evolution reaction (HER) activity is positively correlated to the ECSA changes, the increased C₂H₄ activity is not proportional to the ECSA. Ex situ characterization from microscopic techniques suggests that the changes in the C₂H₄ activity and selectivity may arise from a morphological transformation that evolves into a more active structure. These comprehensive results give rise to the development of a cell regeneration method that can restore the performance of the Cu catalyst without cell disassembly. Our study establishes a basis for the rational design of highly active electrocatalysts for broad-range reactions in a gas-fed device.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acscatal.0c01670DOIArticle
ORCID:
AuthorORCID
Lee, Soo Hong0000-0002-2734-9654
Sullivan, Ian0000-0003-0632-4607
Toma, Francesca M.0000-0003-2332-0798
Xiang, Chengxiang0000-0002-1698-6754
Drisdell, Walter S.0000-0002-8693-4562
Additional Information:© 2020 American Chemical Society. Received: April 13, 2020; Revised: June 11, 2020; Published: June 25, 2020. This material is based on work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-76SF00515. Author Contributions: S.H.L. and I.S. contributed equally to this work. The authors declare no competing financial interest.
Group:JCAP
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Department of Energy (DOE)DE-AC02-76SF00515
Subject Keywords:Operando X-ray absorption spectroscopy, electrochemical CO reduction, oxide-derived copper electrocatalyst, gas diffusion electrode, oxidation state
Issue or Number:14
Record Number:CaltechAUTHORS:20200626-103612366
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20200626-103612366
Official Citation:Correlating Oxidation State and Surface Area to Activity from Operando Studies of Copper CO Electroreduction Catalysts in a Gas-Fed Device. Soo Hong Lee, Ian Sullivan, David M. Larson, Guiji Liu, Francesca M. Toma, Chengxiang Xiang, and Walter S. Drisdell. ACS Catalysis 2020 10 (14), 8000-8011; DOI: 10.1021/acscatal.0c01670
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104072
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:26 Jun 2020 19:35
Last Modified:17 Jul 2020 22:10

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