Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 8, 2015 | Supplemental Material
Journal Article Open

Benchmarking Hydrogen Evolving Reaction and Oxygen Evolving Reaction Electrocatalysts for Solar Water Splitting Devices

Abstract

Objective comparisons of electrocatalyst activity and stability using standard methods under identical conditions are necessary to evaluate the viability of existing electrocatalysts for integration into solar-fuel devices as well as to help inform the development of new catalytic systems. Herein, we use a standard protocol as a primary screen for evaluating the activity, short-term (2 h) stability, and electrochemically active surface area (ECSA) of 18 electrocatalysts for the hydrogen evolution reaction (HER) and 26 electrocatalysts for the oxygen evolution reaction (OER) under conditions relevant to an integrated solar water-splitting device in aqueous acidic or alkaline solution. Our primary figure of merit is the overpotential necessary to achieve a magnitude current density of 10 mA cm^(–2) per geometric area, the approximate current density expected for a 10% efficient solar-to-fuels conversion device under 1 sun illumination. The specific activity per ECSA of each material is also reported. Among HER catalysts, several could operate at 10 mA cm^(–2) with overpotentials <0.1 V in acidic and/or alkaline solutions. Among OER catalysts in acidic solution, no non-noble metal based materials showed promising activity and stability, whereas in alkaline solution many OER catalysts performed with similar activity achieving 10 mA cm–2 current densities at overpotentials of ∼0.33–0.5 V. Most OER catalysts showed comparable or better specific activity per ECSA when compared to Ir and Ru catalysts in alkaline solutions, while most HER catalysts showed much lower specific activity than Pt in both acidic and alkaline solutions. For select catalysts, additional secondary screening measurements were conducted including Faradaic efficiency and extended stability measurements.

Additional Information

© 2015 American Chemical Society. Received: October 10, 2014. Publication Date (Web): February 10, 2015. This material is based upon 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. We thank Joel Haber for providing the NiFeCoCe-(a) and NiFeCoCe-(b) samples and Jesus M. Velazquez for his help in preparing the sputtered Ir and Ru-(b) samples. We also thank Slobodan Mitrovic, Natalie Becerra, and Fadl Saadi for their help with the collection of XPS data. In addition, we acknowledge many useful discussions with Nathan S. Lewis and Carl A. Koval.

Attached Files

Supplemental Material - ja510442p_si_001.pdf

Files

ja510442p_si_001.pdf
Files (2.1 MB)
Name Size Download all
md5:d1b9b44b95dec6ab38f2ea3c6f2fda78
2.1 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 23, 2023