文献类型：期刊文献

英文题名：Nitrogen-Coordinated Single Cobalt Atom Catalysts for Oxygen Reduction in Proton Exchange Membrane Fuel Cells

作者：Wang, Xiao Xia[1,2];Cullen, David A.[3];Pan, Yung-Tin[4];Hwang, Sooyeon[5];Wang, Maoyu[6];Feng, Zhenxing[6];Wang, Jingyun[1];Engelhard, Mark H.[7];Zhang, Hanguang[1];He, Yanghua[1];Shao, Yuyan[7];Su, Dong[5];More, Karren L.[8];Spendelow, Jacob S.[4];Wu, Gang[1]

机构：[1]SUNY Buffalo, Dept Chem & Biol Engn, Buffalo, NY 14260 USA;[2]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[3]Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA;[4]Los Alamos Natl Lab, Mat Phys & Applicat Div, Los Alamos, NM 87545 USA;[5]Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA;[6]Oregon State Univ, Sch Chem Biol & Environm Engn, Corvallis, OR 97331 USA;[7]Pacific Northwest Natl Lab, Washington, DC 99352 USA;[8]Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

年份：2018

卷号：30

期号：11

外文期刊名：ADVANCED MATERIALS

收录：;EI(收录号：20180504683206);WOS:【SCI-EXPANDED(收录号:WOS:000427111300028)】；

基金：This work is financially supported from the start-up funding from the University at Buffalo, SUNY, National Science Foundation (CBET-1604392), and U.S. DOE-EERE Fuel Cell Technologies Office. Electron microscopy research was conducted at the Center for Nanophase Materials Sciences of Oak Ridge National Laboratory and the Center for Functional Nanomaterials at Brookhaven National Laboratory under Contract No. DE-SC0012704, which both are DOE Office of Science User Facilities. XAS measurements were performed at 9BM-C and 4ID-C at Advanced Photon Source of Argonne National Laboratory with support of Department of Energy under Contract No. DE-AC02-06CH11357. Z. Feng thanks the Callahan Faculty Scholar Endowment Fund from Oregon State University. X. X. Wang thanks the Shanghai Natural Science Foundation of China under Contract No. 16ZR1408600. We also thank Shiva Gupta for part of SEM analysis.

语种：英文

外文关键词：carbon nanocomposites; electrocatalysis; oxygen reduction; proton exchange membrane fuel cells; single atomic Co

摘要：Due to the Fenton reaction, the presence of Fe and peroxide in electrodes generates free radicals causing serious degradation of the organic ionomer and the membrane. Pt-free and Fe-free cathode catalysts therefore are urgently needed for durable and inexpensive proton exchange membrane fuel cells (PEMFCs). Herein, a high-performance nitrogen-coordinated single Co atom catalyst is derived from Co-doped metal-organic frameworks (MOFs) through a one-step thermal activation. Aberration-corrected electron microscopy combined with X-ray absorption spectroscopy virtually verifies the CoN4 coordination at an atomic level in the catalysts. Through investigating effects of Co doping contents and thermal activation temperature, an atomically Co site dispersed catalyst with optimal chemical and structural properties has achieved respectable activity and stability for the oxygen reduction reaction (ORR) in challenging acidic media (e.g., half-wave potential of 0.80 V vs reversible hydrogen electrode (RHE). The performance is comparable to Fe-based catalysts and 60 mV lower than Pt/C -60 mu g Pt cm(-2)). Fuel cell tests confirm that catalyst activity and stability can translate to high-performance cathodes in PEMFCs. The remarkably enhanced ORR performance is attributed to the presence of well-dispersed CoN4 active sites embedded in 3D porous MOF-derived carbon particles, omitting any inactive Co aggregates.