Molecular Engineering of Metal-Organic Frameworks as Efficient Electrochemical Catalysts for Water Oxidation

作者：Liu, Yizhe; Li, Xintong; Zhang, Shoufeng; Wang, Zilong^*; Wang, Qi; He, Yonghe; Huang, Wei-Hsiang; Sun, Qidi; Zhong, Xiaoyan; Hu, Jue; Guo, Xuyun; Lin, Qing; Li, Zhuo; Zhu, Ye; Chueh, Chu-Chen; Chen, Chi-Liang; Xu, Zhengtao^*; Zhu, Zonglong^*

来源：Advanced Materials, 2023, 35(22).

DOI：10.1002/adma.202300945

• metal-organic frameworks
• nickel-mercaptan links
• oxygen evolution
• thiol functionalization

Metal-organic framework (MOF) solids with their variable functionalities are relevant for energy conversion technologies. However, the development of electroactive and stable MOFs for electrocatalysis still faces challenges. Here, a molecularly engineered MOF system featuring a 2D coordination network based on mercaptan-metal links (e.g., nickel, as for Ni(DMBD)-MOF) is designed. The crystal structure is solved from microcrystals by a continuous-rotation electron diffraction (cRED) technique. Computational results indicate a metallic electronic structure of Ni(DMBD)-MOF due to the Ni-S coordination, highlighting the effective design of the thiol ligand for enhancing electroconductivity. Additionally, both experimental and theoretical studies indicate that (DMBD)-MOF offers advantages in the electrocatalytic oxygen evolution reaction (OER) over non-thiol (e.g., 1,4-benzene dicarboxylic acid) analog (BDC)-MOF, because it poses fewer energy barriers during the rate-limiting *O intermediate formation step. Iron-substituted NiFe(DMBD)-MOF achieves a current density of 100 mA cm(-2) at a small overpotential of 280 mV, indicating a new MOF platform for efficient OER catalysis.