Heptanuclear brucite disk with cyanide bridges in a cocrystal and tracking its pyrolysis to an efficient oxygen evolution electrode  

作　　者：Jian-Qiang Zhao Dandan Cai Jun Dai Mohamedally Kurmoo Xu Peng Ming-Hua Zeng 

机构地区：[1]Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources,Department of Chemistry and Pharmaceutical Sciences,Guangxi Normal University,Guilin 541004,China [2]Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials,Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules,College of Chemistry and Chemical Engineering,Hubei University,Wuhan 430062,China [3]Institut de Chimie de Strasbourg,CNRS-UMR7177,Universite de Strasbourg,67070 Strasbourg Cedex,France

出　　处：《Science Bulletin》2019年第22期1667-1674,共8页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China for Distinguished Young Scholars (21525101);the BAGUI Talent Program and Scholar Program (2014A001);the National Natural Science Foundation of China (21805074 and 21661008);the Natural Science Foundation of Hubei Province (2017CFA006 and 2018CFB151);the Natural Science Foundation of Guangxi Zhuang Autonomous Region (2017GXNSFDA198040);supported by the Centre National de la Recherche Cientifique (CNRS, France)

摘　　要：The development of efficient oxygen evolution reaction(OER)catalysts is still lacking in exploration of the mechanism of controlled pyrolysis of precursors among new material platforms.Here,a novel Co-based coordination molecular cluster has been first introduced as precursor to obtain metallic cobalt core shelled by N-doped carbon(Co@NC)structure which operates as an oxygen evolution electrode.Specifically,a new cocrystal compound,[Co7II(l3-CN)6(mmimp)6][CoIICl3N(CN)2]á3CH3OH(Co7+1,mmimp=2-methoxy-6-((methylimino)-methyl)phenol),was isolated consisting of Brucite disks of cobalt where the usual bridging l3-OH is replaced by l3-CN produced by the in-situ decomposition of dicyanamide(NC-N-CNà).The cobalt atoms are bonded through the nitrogen atom of the cyanide.Remarkably,time dependent thermogravimetric-mass spectrometry(TG-MS)analysis was utilized to track its pyrolysis process.It allowed us to propose a possible formation process of the Co@NC structure from Co7+1.Interestingly,an extremely superior OER electrode is optimized for Co@NC-600 having the lowest overpotential of257 m V at 10 m A/cm2in 1 mol/L KOH solution.The present study pins down the importance of clusters of transition metals on realizing distinct nanostructures operating as highly efficient OER electrocatalyst.The development of efficient oxygen evolution reaction（OER）catalysts is still lacking in exploration of the mechanism of controlled pyrolysis of precursors among new material platforms.Here,a novel Co-based coordination molecular cluster has been first introduced as precursor to obtain metallic cobalt core shelled by N-doped carbon（Co@NC）structure which operates as an oxygen evolution electrode.Specifically,a new cocrystal compound,[Co7II（l3-CN）6（mmimp）6][CoIICl3N（CN）2]á3CH3OH(Co7+1,mmimp=2-methoxy-6-（（methylimino）-methyl）phenol),was isolated consisting of Brucite disks of cobalt where the usual bridging l3-OH is replaced by l3-CN produced by the in-situ decomposition of dicyanamide（NC-N-CNà）.The cobalt atoms are bonded through the nitrogen atom of the cyanide.Remarkably,time dependent thermogravimetric-mass spectrometry（TG-MS）analysis was utilized to track its pyrolysis process.It allowed us to propose a possible formation process of the Co@NC structure from Co7+1.Interestingly,an extremely superior OER electrode is optimized for Co@NC-600 having the lowest overpotential of257 m V at 10 m A/cm2in 1 mol/L KOH solution.The present study pins down the importance of clusters of transition metals on realizing distinct nanostructures operating as highly efficient OER electrocatalyst.

关 键 词：Cobalt DISK clusters Thermogravimetry-mass spectrometry PYROLYSIS tracking Core-shell nanostructure Oxygen evolution reaction 

分 类 号：O64[理学—物理化学]