Liu Meihuan, Su Hui, Cheng Weiren, Yu Feifan, Li Yuanli, Zhou Wanlin, Zhang Hui, Sun Xuan, Zhang Xiuxiu, Wei Shiqiang, Liu Qinghua
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, P. R. China.
Institute for Catalysis Hokkaido University, Sapporo, 001-0021, Japan.
Small. 2022 Jul;18(27):e2202248. doi: 10.1002/smll.202202248. Epub 2022 Jun 9.
Herein, a strategy of synergetic dual-metal-ion centers to boost transition-metal-based metal organic framework (MOF) alloy nanomaterials as active oxygen reduction reaction (ORR) electrocatalysts for efficient hydrogen peroxide (H O ) generation is proposed. Through a facile one-pot wet chemical method, a series of MOF alloys with unique Ni-M (M-Co, Cu, Zn) synergetic centers are synthesized, where the strong metallic ions 3d-3d synergy can effectively inhibit O cleavage on Ni sites toward a favorable two-electron ORR pathway. Impressively, the well-designed NiZn MOF alloy catalysts show an excellent H O selectivity up to 90% during ORR, evidently outperforming that of NiCo MOF (45%), and NiCu MOF (55%). Moreover, it sustains efficient activity and robust stability under a continuous longterm ORR operation. The correlative in situ synchrotron radiation X-ray adsorption fine structure and Fourier transform infrared spectroscopy analyses reveal at the atomic level that, the higher Ni oxidation states species, regulated via adjacent Zn ions, are favorable for optimizing the adsorption energetics of key *OOH intermediates toward fast two electron ORR kinetics.
在此，我们提出了一种协同双金属离子中心策略，以促进基于过渡金属的金属有机框架（MOF）合金纳米材料作为活性氧还原反应（ORR）电催化剂，用于高效生成过氧化氢（H₂O₂）。通过简便的一锅湿化学方法，合成了一系列具有独特Ni-M（M = Co、Cu、Zn）协同中心的MOF合金，其中强金属离子的3d-3d协同作用可以有效抑制Ni位点上的O裂解，从而有利于形成有利的双电子ORR途径。令人印象深刻的是，精心设计的NiZn MOF合金催化剂在ORR过程中显示出高达90%的优异H₂O₂选择性，明显优于NiCo MOF（45%）和NiCu MOF（55%）。此外，在连续长期的ORR操作下，它保持了高效的活性和强大的稳定性。相关的原位同步辐射X射线吸收精细结构和傅里叶变换红外光谱分析在原子水平上揭示，通过相邻的Zn离子调节的较高Ni氧化态物种有利于优化关键*OOH中间体的吸附能，从而实现快速的双电子ORR动力学。
