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Published December 9, 2022 | public
Journal Article

Powdered Mn_(y)Sb_(1-y)O_(x) Catalysts for Cerium-Mediated Oxygen Evolution in Acidic Environments

Abstract

Mn_(y)Sb_(1-y)O_(x) powders with a series of compositions were evaluated as catalysts for chemical water oxidation in aqueous perchloric, sulfuric, or methanesulfonic acid. O₂(g) evolved spontaneously over Mn_(y)Sb_(1-y)O_(x) catalyst powders that had been suspended in solutions that were pre-loaded with Ce⁴⁺ ions. The rate of O₂ evolution depended on the amount, as well as the oxidation state, of the Mn in the powder. The highest O₂ evolution rate was observed from the most Mn-rich catalyst, which had an effective surface oxidation state of Mn²⋅⁹⁺ in its rest state. The facile synthetic accessibility of such catalysts in powder form constitutes a step toward replacing Ir or Ru in Ce-mediated oxygen evolution in decoupled water splitting systems, as well as toward developing inks of earth-abundant catalysts for preparation of catalyst-coated membranes used in conventional proton-exchange membrane electrolyzers.

Additional Information

This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under award number DE-SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, and under award DE-SC0022087 from the Basic Energy Sciences Office of the DOE. XPS and DRS data were collected at the Molecular Materials Resource Center of the Beckman Institute of the California Institute of Technology. ICP-MS instrumentation at the Resnick Sustainability Institute's Water and Environment Lab at the California Institute of Technology was used in this work. We thank Madeline C. Meier for assistance with illustrations and schematic design and Dr. Nathan Dalleska for assistance with the ICP-MS.

Additional details

Created:
August 22, 2023
Modified:
October 24, 2023