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Published September 28, 2022 | Supplemental Material + Published
Journal Article Open

Tuning Single-Atom Dopants on Manganese Oxide for Selective Electrocatalytic Cyclooctene Epoxidation

Abstract

Selective and efficient electrocatalysts are imperative for the successful deployment of electrochemistry toward synthetic applications. In this study, we used galvanic replacement reactions to synthesize iridium-decorated manganese oxide nanoparticles, which showed a cyclooctene epoxidation partial current density of 10.5 ± 2.8 mA/cm² and a Faradaic efficiency of 46 ± 4%. Results from operando X-ray absorption spectroscopy suggest that manganese leaching from the nanoparticles during galvanic replacement introduces lattice vacancies that make the nanoparticles more susceptible to metal oxidation and catalyst reconstruction under an applied anodic potential. This results in an increased presence of electrophilic oxygen atoms on the catalyst surface during reaction conditions, which may contribute to the enhanced electrocatalytic activity toward cyclooctene epoxidation.

Additional Information

© 2022 The Authors. Published by American Chemical Society. Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). This research was supported by the U.S. Department of Energy (DOE) Office of Science, Office of Basic Energy Sciences, Catalysis Science Program, under Award No. DE-SC0020999. This research used resources of the National Synchrotron Light Source II, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. This research also used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. The authors are grateful to Eli Stavitski, Denis Leshchev, Steven Ehrlich, Lu Ma, and Sirine Fakra for their help in operating XAS experiments. This work was performed in part at the Harvard University Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF Award No. ECCS-2025158. The authors appreciate Jules Gardner at CNS for taking HAADF-STEM images. M.C. gratefully acknowledges the support of the Kwanjeong Fellowship. Author Contributions. M.C. and K.J. contributed equally to this work. All authors have given approval to the final version of the manuscript. The authors declare no competing financial interest.

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Additional details

Created:
August 22, 2023
Modified:
November 16, 2023