当前位置: X-MOL 学术ChemSusChem › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Understanding the Evolution of Cobalt-Based Metal-Organic Frameworks in Electrocatalysis for the Oxygen Evolution Reaction
ChemSusChem ( IF 7.5 ) Pub Date : 2021-06-08 , DOI: 10.1002/cssc.202100851
Xiaowei Cai 1 , Fei Peng 1 , Xingyu Luo 1 , Xuejie Ye 1 , Junxi Zhou 1 , Xiaoling Lang 2 , Meiqin Shi 1
Affiliation  

Metal-organic frameworks (MOFs) have attracted increasing attention as a promising electrode material for the oxygen evolution reaction (OER). Comprehending catalytic mechanisms in the OER process is of key relevance for the design of efficient catalysts. In this study, two types of Co based MOF with different organic ligands (ZIF-67 and CoBDC; BDC=1,4-benzenedicarboxylate) are synthesized as OER electrocatalysts and their electrochemical behavior is studied in alkaline solution. Physical characterization indicates that ZIF-67, with tetrahedral Co sites, transforms into α-Co(OH)2 on electrochemical activation, which provides continuous active sites in the following oxidation, whereas CoBDC, with octahedral sites, evolves into β-Co(OH)2 through hydrolysis, which is inert for the OER. Electrochemical characterization reveals that Co sites coordinated by nitrogen from imidazole ligands (Co−N coordination) are more inclined to electrochemical activation than Co−O sites. The successive exposure and accumulation of real active sites is responsible for the gradual increase in activity of ZIF-67 in OER. This work not only indicates that CoMOFs are promising OER electrocatalysts but also provides a reference system to understand how metal coordination in MOFs affects the OER process.

中文翻译:

了解钴基金属-有机骨架在氧释放反应电催化中的演变

金属有机框架(MOFs)作为一种有前途的析氧反应(OER)电极材料引起了越来越多的关注。理解 OER 过程中的催化机制对于设计高效催化剂具有关键意义。在这项研究中,合成了两种具有不同有机配体的 Co 基 MOF(ZIF-67 和 CoBDC;BDC=1,4-苯二羧酸盐)作为 OER 电催化剂,并研究了它们在碱性溶液中的电化学行为。物理表征表明,具有四面体 Co 位点的 ZIF-67在电化学活化时转化为 α-Co(OH) 2,在接下来的氧化中提供连续的活性位点,而具有八面体位点的 CoBDC 则演变为 β-Co(OH) ) 2通过水解,这对 OER 是惰性的。电化学表征表明,与来自咪唑配体的氮配位的 Co 位点(Co-N 配位)比 Co-O 位点更倾向于电化学活化。真实活性位点的连续暴露和积累是 OER 中 ZIF-67 活性逐渐增加的原因。这项工作不仅表明 CoMOF 是有前途的 OER 电催化剂,而且还提供了一个参考系统,以了解 MOF 中的金属配位如何影响 OER 过程。
更新日期:2021-08-12
down
wechat
bug