Nsanzimana Jean Marie Vianney, Jose Vishal, Sk Mukaddar, Reddu Vikas, Xiaogang Li, Dangol Raksha, Hao Ren, Huang Zhenfeng, Yan Qingyu, Thapa Ranjit, Maiyalagan Thandavarayan, Wang Xin, Lee Jong-Min
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
University of Siegen, Paul-Bonatz-Straße 9-11, 57076, Siegen, Germany.
Small. 2025 Jul;21(27):e2500587. doi: 10.1002/smll.202500587. Epub 2025 Jun 2.
Earth-abundant transition metal-based catalysts with exceptional bifunctionality for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are greatly desired. Alloyed catalysts, such as molybdenum-nickel (MoNi), are known to demonstrate enhanced HER activity, yet suffer from low OER performance. To realize improved functionality, elemental doping can be an effective approach, giving rise to synergistic interactions between incorporated metal species, optimizing surface adsorption of target intermediates, and promoting reaction. Herein, the enhanced OER performance of the MoNi catalyst while simultaneously boosting HER activity via incorporating a small amount of iron and chromium into MoNi (Mo-Ni(FeCr)) is demonstrated. For an optimized Mo-Ni(FeCr) catalyst, in 1.0 m potassium hydroxide electrolyte, an overpotential of only 11 and 179 mV for HER and OER, respectively, are required to afford a current density of 10 mA cm. For the overall water splitting, a current density of 20 mA cm is reached at 1.489 V. The DFT calculations demonstrated that the inclusion of Fe and Cr in a molybdenum-nickel catalyst reduced the limiting potentials for both OER and HER, unlocking efficient bifunctionality activity for water splitting. These findings signify the improved electrocatalytic performance of, amongst the most active bifunctional electrocatalysts.
人们迫切需要具有出色的析氢反应（HER）和析氧反应（OER）双功能的地球丰富型过渡金属基催化剂。合金催化剂，如钼镍（MoNi），已知具有增强的HER活性，但OER性能较差。为了实现功能的改进，元素掺杂可能是一种有效的方法，它会在掺入的金属物种之间产生协同相互作用，优化目标中间体的表面吸附，并促进反应。在此，展示了通过将少量铁和铬掺入MoNi（Mo-Ni(FeCr)）中来提高MoNi催化剂的OER性能，同时增强HER活性。对于优化后的Mo-Ni(FeCr)催化剂，在1.0 M氢氧化钾电解质中，分别提供10 mA cm²的电流密度时，HER和OER的过电位仅为11和179 mV。对于整体水分解，在1.489 V时达到20 mA cm²的电流密度。密度泛函理论（DFT）计算表明，在钼镍催化剂中加入铁和铬降低了OER和HER的极限电位，开启了高效的水分解双功能活性。这些发现表明，在最活跃的双功能电催化剂中，其电催化性能得到了改善。
