Rui Jiang1, Li Li1, Tian Sheng2, Gaofei Hu1, Yueguang Chen1, Leyu Wang1. 1. State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering , Beijing University of Chemical Technology , Beijing 100029 , China. 2. College of Chemistry and Materials Science , Anhui Normal University , Wuhu 241000 , China.
Abstract
Single-atom metal-nitrogen-carbon (M-N-C) catalysts have sparked intense interests, but the catalytic contribution of N-bonding environment neighboring M-N4 sites lacks attention. Herein, a series of Fe-N-C nanoarchitectures have been prepared, which confer adjustable numbers of atomically dispersed Fe-N4 sites, tunable hierarchical micro-mesoporous structures and intensified exposure of interior active sites. The optimization between Fe-N4 single sites and carbon matrix delivers superior oxygen reduction reaction activity (half-wave potential of 0.915 V vs RHE in alkaline medium) with remarkable stability and high atom-utilization efficiency (almost 10-fold enhancement). Both experiments and theoretical calculations verified the selective C-N bond cleavage adjacent to Fe center induced by porosity engineering could form edge-hosted Fe-N4 moieties, and therefore lower the overall oxygen reduction reaction barriers comparing to intact atomic configuration. These findings provide a new pathway for the integrated engineering of geometric and electronic structures of single-atom materials to improve their catalytic performance.
Single-atom metal-n class="Chemical">nitrogen-carbon (M-N-C) catalysts have sparked intense interests, but the catalytic contribution of N-bonding environment neighboring M-N4 sites lacks attention. Herein, a series of Fe-N-C nanoarchitectures have been prepared, which confer adjustable numbers of atomically dispersed Fe-N4 sites, tunable hierarchical micro-mesoporous structures and intensified exposure of interior active sites. The optimization between Fe-N4 single sites and carbon matrix delivers superior oxygen reduction reaction activity (half-wave potential of 0.915 V vs RHE in alkaline medium) with remarkable stability and high atom-utilization efficiency (almost 10-fold enhancement). Both experiments and theoretical calculations verified the selective C-N bond cleavage adjacent to Fe center induced by porosity engineering could form edge-hosted Fe-N4 moieties, and therefore lower the overall oxygen reduction reaction barriers comparing to intact atomic configuration. These findings provide a new pathway for the integrated engineering of geometric and electronic structures of single-atom materials to improve their catalytic performance.
Authors: Liqun Kang; Bolun Wang; Adam Thetford; Ke Wu; Mohsen Danaie; Qian He; Emma K Gibson; Ling-Dong Sun; Hiroyuki Asakura; C Richard A Catlow; Feng Ryan Wang Journal: Angew Chem Int Ed Engl Date: 2020-11-13 Impact factor: 15.336
Authors: Ting He; Bingzhang Lu; Yang Chen; Yong Wang; Yaqiang Zhang; John L Davenport; Alan P Chen; Chih-Wen Pao; Min Liu; Zhifang Sun; Alexander Stram; Alexander Mordaunt; Jairo Velasco; Yuan Ping; Yi Zhang; Shaowei Chen Journal: Research (Wash D C) Date: 2019-12-20