Li Yinghao, Peng Chun-Kuo, Sun Yuntong, Sui L D Nicole, Chang Yu-Chung, Chen San-Yuan, Zhou Yingtang, Lin Yan-Gu, Lee Jong-Min
School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
Department of Material Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan.
Nat Commun. 2024 Nov 25;15(1):10222. doi: 10.1038/s41467-024-54589-0.
Precise morphological control and identification of structure-property relationships pose formidable challenges for high-entropy alloys, severely limiting their rational design and application in multistep and tandem reactions. Herein, we report the synthesis of sub-nanometric high-entropy metallenes with up to eight metallic elements via a one-pot wet-chemical approach. The PdRhMoFeMn high-entropy metallenes exhibit high electrocatalytic hydrogen evolution performances with 6, 23, and 26 mV overpotentials at -10 mA cm in acidic, neutral, and alkaline media, respectively, and high stability. The electrochemical measurements, theoretical simulations, and operando X-ray absorption spectroscopy reveal the actual active sites along with their dynamics and synergistic mechanisms in various electrolytes. Specially, Mn sites have strong binding affinity to hydroxyl groups, which enhances the water dissociation process at Pd sites with low energy barrier while Rh sites with optimal hydrogen adsorption free energy accelerate hydride coupling, thereby markedly boosting its intrinsic ability for hydrogen production.
精确的形态控制以及对结构-性能关系的识别给高熵合金带来了巨大挑战，严重限制了它们在多步和串联反应中的合理设计与应用。在此，我们报告了通过一锅湿化学方法合成的包含多达八种金属元素的亚纳米级高熵金属烯。PdRhMoFeMn高熵金属烯在酸性、中性和碱性介质中，在-10 mA cm²时分别具有6、23和26 mV的过电位，展现出高的电催化析氢性能以及高稳定性。电化学测量、理论模拟和原位X射线吸收光谱揭示了在各种电解质中实际的活性位点及其动力学和协同机制。特别地，Mn位点对羟基具有很强的结合亲和力，这在低能垒下增强了Pd位点的水离解过程，而具有最佳氢吸附自由能的Rh位点加速了氢化物偶联，从而显著提高了其产氢的内在能力。
