Zhai Jingrong, Kang Qiaoling, Liu Qiuyue, Lai Dawei, Lu Qingyi, Gao Feng
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, PR China.
Department of Materials Science and Engineering, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, PR China.
J Colloid Interface Sci. 2022 Feb 15;608(Pt 2):1942-1950. doi: 10.1016/j.jcis.2021.10.096. Epub 2021 Oct 23.
Three-dimensional (3D) network structure of metal-organic framework (MOF) can accommodate outstanding electrocatalysis performances, but always collapse during the conversion to active materials or applications process. How to maintain the 3D network when producing active species is of great importance for full application of MOF. Herein, a new MOF material, In[Co(CN)] (In-Co PBA) nanocubes, are firstly synthesized. Through a controlled low-temperature deligandation process, the In-Co PBA nanocubes are transformed to a novel InO@In-Co PBA quasi-MOF nanocubes, which basically retain the 3D porous structure of PBA but with in situ generated InO nanoparticles inside. When used as CORR electrocatalyst, such a novel cubic composite structure exhibits excellent performances with faradaic efficiency of 85% for formate at a potential of -0.96 V and with current density of 31.5 mA·cm at -1.32 V, surpassing most of the reported indium-based catalysts. The excellent performance can be attributed to the special composite structure, which provides not only active sites by InO nanoparticles to catalyze CORR, but also the 3D porous framework by quasi-MOF to accelerate gaseous exchange and electrolyte permeation and prevent the electrode choking. This work offers a new strategy for the design of post-transition metal catalysts and the structure design of quasi-MOF.
金属有机框架（MOF）的三维（3D）网络结构能够实现出色的电催化性能，但在转化为活性材料或应用过程中往往会坍塌。在制备活性物种时如何保持3D网络结构对于MOF的充分应用至关重要。在此，首次合成了一种新型MOF材料铟[钴（氰基）]（In-Co PBA）纳米立方体。通过可控的低温脱配体过程，In-Co PBA纳米立方体转变为一种新型的InO@In-Co PBA准MOF纳米立方体，其基本保留了PBA的3D多孔结构，但内部原位生成了InO纳米颗粒。当用作CORR电催化剂时，这种新型立方复合结构表现出优异的性能，在-0.96 V的电位下对甲酸盐的法拉第效率为85%，在-1.32 V时电流密度为31.5 mA·cm，超过了大多数已报道的铟基催化剂。优异的性能可归因于特殊的复合结构，它不仅通过InO纳米颗粒提供活性位点来催化CORR，还通过准MOF提供3D多孔框架来加速气体交换和电解质渗透并防止电极堵塞。这项工作为后过渡金属催化剂的设计和准MOF的结构设计提供了一种新策略。
