Accelerated Characterization of Electrode‐Electrolyte Equilibration
Abstract
Operational durability is poorly characterized by traditional (photo)electrocatalyst discovery workflows, creating a barrier to scale-up and deployment. Corrosion is a prominent degradation mechanism whose thermodynamics depend on the concentration of corrosion products in electrolyte. We present an automated system for characterizing the equilibration of (photo)electrodes with dissolved metals in electrolyte for a given electrode, pH, and electrochemical potential. Automation of electrode selection, electrolyte preparation, and electrolyte aliquoting enables rapid identification of self-passivating electrodes and estimation of the equilibrium dissolved metals concentrations. The technique is demonstrated for metal oxide photoanodes in alkaline electrolyte, where BiVO4 is found to continually corrode, in agreement the literature. An amorphous Ni−Sb−O photoanode is found to passivate with a Ni-rich coating on the order of 1 monolayer with less than 1 μM total dissolved metals in electrolyte, demonstrating its suitability for durable photoelectrochemical operation. The automation and throughput of the instrument are designed for incorporation in accelerated electrocatalyst discovery workflows so that durability can be considered on equal footing with activity.
Copyright and License
© 2023 The Authors. ChemCatChem published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Acknowledgement
This material is primarily supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award DE-SC0023139. Fabrication of the ADSS instrument was supported by the Liquid Sunlight Alliance, which is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under Award DE-SC0021266.
Data Availability
The data that support the findings of this study are openly available in CaltechData at https://doi.org/10.22002/1n669-dte30, reference number 1n669-dte30. This data package contains data files and the Python code for processing ICP-MS data into the modelled thicknesses, including the rendering of figures, and is also available at https://github.com/High-Throughput-Experimentation/ADSS-SI. Computer drawings of the ADSS instrument are available at https://data.caltech.edu/records/m6btr-szr71 (DOI: 10.22002/m6btr-szr71).
A flowchart for ADSS experiments; the model for determining the thickness of the corrosion and coating layers, as well as the associated uncertainties; and tables of all ICP-MS data, as well as their analysis, are included as Supporting Information.
Conflict of Interest
J. M. G. is a consultant for companies that aim to accelerate catalyst discovery.
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Additional details
- ISSN
- 1867-3899
- DE-SC0023139
- United States Department of Energy
- DE-SC0021266
- United States Department of Energy
- Caltech groups
- Liquid Sunlight Alliance