Department of Chemistry, City University of Hong Kong, Kowloon, 999077, Hong Kong.
Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China.
Adv Mater. 2023 Jun;35(22):e2300945. doi: 10.1002/adma.202300945. Epub 2023 Apr 14.
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 at a small overpotential of 280 mV, indicating a new MOF platform for efficient OER catalysis.
金属-有机骨架（MOF）固体因其多功能性而与能量转换技术相关。然而，开发用于电催化的电活性和稳定的 MOF 仍然面临挑战。在这里，设计了一种基于巯基-金属键（例如，镍，对于 Ni(DMBD)-MOF）的二维配位网络的分子工程 MOF 系统。通过连续旋转电子衍射（cRED）技术从小晶体中解析出晶体结构。计算结果表明 Ni(DMBD)-MOF 具有金属电子结构，这是由于 Ni-S 配位所致，突出了硫醇配体在增强导电性方面的有效设计。此外，实验和理论研究都表明，（DMBD）-MOF 在电催化氧气析出反应（OER）中优于非硫醇（例如，1,4-苯二甲酸）类似物（BDC）-MOF，因为它在限速*O 中间形成步骤中具有更少的能量障碍。铁取代的 NiFe(DMBD)-MOF 在 280 mV 的小过电势下达到 100 mA cm 的电流密度，表明其为高效 OER 催化提供了新的 MOF 平台。
