Characterizing CO2 Reduction Catalysts on Gas Diffusion Electrodes: Comparing Activity, Selectivity, and Stability of Transition Metal Catalysts

Characterizing CO2 Reduction Catalysts on Gas Diffusion Electrodes: Comparing Activity, Selectivity, and Stability of Transition Metal Catalysts

Burdyny, T.E. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Sassenburg, M. (TU Delft ChemE/Materials for Energy Conversion and Storage)
de Rooij, R. (Student TU Delft)
Nessbit, Nathan (Student TU Delft)
Kas, R. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Chandrashekar, S. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Firet, N.J. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Yang, K. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Liu, K. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Blommaert, M.A. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Kolen, M. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Ripepi, D. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage)

2022

Continued advancements in the electrochemical reduction of CO 2 (CO 2RR) have emphasized that reactivity,selectivity, and stability are not explicit material properties butcombined effects of the catalyst, double-layer, reaction environ-
ment, and system configuration. These realizations have steadily built upon the foundational work performed for a broad array of transition metals performed at 5 mA cm−2, which historically guided the research field. To encompass the changing advancements and mindset within the research field, an updated baseline at elevated current densities could then be of value. Here we seek to
re-characterize the activity, selectivity, and stability of the five most utilized transition metal catalysts for CO2 RR (Ag, Au, Pd, Sn, and Cu) at elevated reaction rates through electrochemical operation, physical characterization, and varied operating parameters to provide a renewed resource and point of comparison. As a basis, we have employed a common cell architecture, highly controlled catalyst layer morphologies and thicknesses, and fixed current densities. Through a dataset of 88 separate experiments, we provide comparisons between CO-producing catalysts (Ag, Au, and Pd), highlighting CO-limiting current densities on Au and Pd at 72 and 50 mA cm−2, respectively. We further show the instability of Sn in highly alkaline environments, and the convergence of product selectivity at elevated current densities for a Cu catalyst in neutral andalkaline media. Lastly, we reflect upon the use and limits of reaction rates as a baseline metric by comparing catalytic selectivity at 10
versus 200 mA cm−2. We hope the collective work provides a resource for researchers setting up CO 2RR experiments for the first time.

CO2 reduction
gas diffusion electrode
catalyst comparison
silver
gold
palladium
tin
copper

http://resolver.tudelft.nl/uuid:6bb7abeb-90e3-4b1a-bb41-d4da94cb6d70

https://doi.org/10.1021/acsaem.2c00160

2574-0962

ACS Applied Energy Materials

Institutional Repository

journal article

© 2022 T.E. Burdyny, M. Sassenburg, R. de Rooij, Nathan Nessbit, R. Kas, S. Chandrashekar, N.J. Firet, K. Yang, K. Liu, M.A. Blommaert, M. Kolen, D. Ripepi, W.A. Smith