Konavarapu Satyanarayana K, Kim Giyong, Shin Kyuchul, Kim Sung Yeol
School of Mechanical Engineering, Kyungpook National University, Daegu, 702-701, Republic of Korea.
School of Chemical Engineering and Applied Chemistry (Graduate School) Kyungpook National University, Daegu, Republic of Korea.
Chemistry. 2025 Apr;31(24):e202500010. doi: 10.1002/chem.202500010. Epub 2025 Mar 30.
Due to the decreasing availability, reduced stability, and high cost of noble metal-based catalysts, the search for stable, efficient, and inexpensive electrocatalysts is of significant importance. In this study, three new isostructural Co(II), Ni(II), and CoNi metal-organic frameworks (MOFs) based on bis-coordinating ligand 3-pyridyl acrylic acid are explored as efficient electrocatalysts. The structure of CoNi-MOF was further confirmed by various experimental techniques. The electrocatalytic activities toward the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) revealed that the bimetallic CoNi-MOF demonstrated significantly greater activity towards OER and HER compared to its monometallic counterparts, Co-MOF and Ni-MOF. CoNi-MOF requires 350 mV and 150 mV overpotential to achieve a current density of 10 mA cm for OER and HER, respectively. Moreover, they exhibited excellent stability for 6 hours and 1000 OER cycles, demonstrating its superiority in these reactions. The significant enhancement in the performance of CoNi-MOF is attributed to the bimetallic synergistic effects between the redox-active metal centers Co and Ni, which increase the activity of the catalyst's surface, resulting in enhanced current density and reduced overpotential. The hydrogen bond between coordinated water molecules and un-coordinated carboxylate is essential for the electrochemical stability of the materials.
由于基于贵金属的催化剂可用性降低、稳定性下降且成本高昂，寻找稳定、高效且廉价的电催化剂具有重要意义。在本研究中，探索了三种基于双配位配体3-吡啶基丙烯酸的新型同构Co(II)、Ni(II)和CoNi金属有机框架（MOF）作为高效电催化剂。通过各种实验技术进一步证实了CoNi-MOF的结构。对析氧反应（OER）和析氢反应（HER）的电催化活性表明，双金属CoNi-MOF对OER和HER的活性明显高于其单金属对应物Co-MOF和Ni-MOF。CoNi-MOF分别需要350 mV和150 mV的过电位才能实现10 mA cm的OER和HER电流密度。此外，它们在6小时和1000次OER循环中表现出优异的稳定性，证明了其在这些反应中的优越性。CoNi-MOF性能的显著提高归因于氧化还原活性金属中心Co和Ni之间的双金属协同效应，这增加了催化剂表面的活性，导致电流密度增强和过电位降低。配位水分子与未配位羧酸盐之间的氢键对于材料的电化学稳定性至关重要。
