Single-Atom Catalysts for Selective Oxygen Reduction: Transition Metals in Uniform Carbon Nanospheres with High Loadings

• Type of Material: Article
• Authors: Jacob Jeskey, Georgia Institute of Technology; Yong Ding, Georgia Institute of Technology; Yidan Chen, Georgia Institute of Technology; Zachary D. Hood, Argonne National Laboratory; George E. Sterbinksy, Argonne National Laboratory; Mietek Jaroniec, Kent State University; Younan Xia, Emory University
• Language: English
• Date: 2023-10-19
• Publisher: American Chemical Society
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors. Published by American Chemical Society
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): https://doi.org/10.1021/jacsau.3c00557
• Title of Journal or Parent Work: JACS Au
• Volume: 3
• Issue: 11
• Start Page: 3227
• End Page: 3236
• Grant/Funding Information: This work was supported in part by a grant from the NSF (CBET-2219546) and startup funds from Georgia Tech. Part of the electron microscopy characterization work was performed at the Georgia Tech Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (ECCS-2025462). This research also used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
• Keywords: oxygen reduction reaction; chemical confinement; single-atom catalyst; one-pot; carbon nanospheres
• Research Categories: Environmental Sciences; Chemistry, Inorganic

Abstract

Transition metal single-atom catalysts (SACs) in uniform carbon nanospheres have gained tremendous interest as electrocatalysts owing to their low cost, high activity, and excellent selectivity. However, their preparation typically involves complicated multistep processes that are not practical for industrial use. Herein, we report a facile one-pot method to produce atomically isolated metal atoms with high loadings in uniform carbon nanospheres without any templates or postsynthesis modifications. Specifically, we use a chemical confinement strategy to suppress the formation of metal nanoparticles by introducing ethylenediaminetetraacetic acid (EDTA) as a molecular barrier to spatially isolate the metal atoms and thus generate SACs. To demonstrate the versatility of this synthetic method, we produced SACs from multiple transition metals, including Fe, Co, Cu, and Ni, with loadings as high as 3.87 wt %. Among these catalytic materials, the Fe-based SACs showed remarkable catalytic activity toward the oxygen reduction reaction (ORR), achieving an onset and half-wave potential of 1.00 and 0.831 VRHE, respectively, comparable to that of commercial 20 wt % Pt/C. Significantly, we were able to steer the ORR selectivity toward either energy generation or hydrogen peroxide production by simply changing the transition metal in the EDTA-based precursor.