Sanati Soheila, Abazari Reza, Kirillov Alexander M
Department of Chemistry, Faculty of Science, University of Maragheh, Maragheh P.O. Box 55181-83111, Iran.
Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisbon 1049-001, Portugal.
Inorg Chem. 2024 Aug 26;63(34):15813-15820. doi: 10.1021/acs.inorgchem.4c01850. Epub 2024 Aug 14.
The urea oxidation reaction (UOR) is an alternative anodic reaction for hydrogen generation via water splitting. The significance of UOR lies in both H production and the decontamination of urea-containing wastewater. Commercial electrocatalysts in this field are generally based on noble metals and show several limitations. Bimetal-organic frameworks (BMOFs) can be excellent candidates for the replacement of noble-metal-based catalysts beacuse of their promising features, such as a tunable structure, high surface area, and abundant sites for electrocatalysis. In this study, a series of nickel-cobalt BMOFs (Ni-Co-BMOFs: and refer to a molar fraction of Ni and Co) were synthesized and applied as electrocatalysts in UOR. In particular, a NiCo-MOF material with a structure similar to that of its parent Co-MOF, revealed exceptional electrocatalytic performance, as evidenced by low values of overpotential (1.33 V vs RHE at 10 mA cm), TOF (0.47 s), and Tafel slope (125 mV dec). At a 40 mA cm current density, NiCo-MOF also showed excellent stability during the 72 h tests. This performance of NiCo-BMOF can be assigned to the synergistic effect between Co and Ni, abundant active sites, porosity, and a tunable structure, all of which result in an increased reaction rate due to the acceleration of charge and mass transfers. Thus, the present work introduces an efficient noble-metal-free UOR for energy generation from urea-based wastewater.
尿素氧化反应（UOR）是一种通过水分解产生氢气的替代阳极反应。UOR的意义在于制氢以及对含尿素废水的净化。该领域的商业电催化剂通常基于贵金属，存在一些局限性。双金属有机框架（BMOFs）因其具有诸如可调节结构、高比表面积和丰富的电催化位点等有前景的特性，有望成为替代基于贵金属催化剂的优秀候选材料。在本研究中，合成了一系列镍钴BMOFs（Ni-Co-BMOFs： 和 分别指Ni和Co的摩尔分数）并将其用作UOR中的电催化剂。特别是，一种结构与其母体Co-MOF相似的NiCo-MOF材料表现出卓越的电催化性能，过电位低（在10 mA cm时相对于可逆氢电极（RHE）为1.33 V）、周转频率（TOF，0.47 s）和塔菲尔斜率（125 mV dec）即为证明。在40 mA cm的电流密度下，NiCo-MOF在72小时测试期间也表现出优异的稳定性。NiCo-BMOF的这种性能可归因于Co和Ni之间的协同效应、丰富的活性位点、孔隙率和可调节结构，所有这些都因电荷和质量传递的加速而导致反应速率增加。因此，本工作引入了一种用于从尿素基废水中产生能量的高效无贵金属UOR。
