Wang Yan, Meng Huiying, Yu Renqin, Hong Jie, Zhang Yifan, Xia Zhonghong, Wang Yong
School of Environmental & Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai, 200444, China.
Angew Chem Int Ed Engl. 2025 Mar 3;64(10):e202420752. doi: 10.1002/anie.202420752. Epub 2025 Feb 7.
Developing ethanol oxidation electrocatalysts with high catalytic activity, durability, and resistance to CO poisoning remains a major challenge. In recent years, high-entropy alloys (HEAs) with unique physical and chemical properties have garnered substantial attention. Herein, a class of HEA nanodendrites are designed by a simple wet-chemical method. The mass activity and specific activity of the septenary PtIrRhCoFeNiCu high-entropy alloy catalyst are 2.13 A mg /1.05 A mg and 2.95 mA cm, which reach 5.76-/2.84-fold and 5.57-fold improvements relative to commercial Pt/C (0.37 A mg and 0.53 mA cm), respectively. Remarkably, after the i-t test of up to 100,000 s and the accelerated durability test of 1500 cycles, 81.22 % and 68.54 % of the initial mass activity are well retained, respectively. The lattice distortion-associated local tensile strain as demonstrated by increased Pt-Pt bond length enhances ethanol adsorption and reduces reaction barriers. Moreover, hysteresis diffusion effect induced by lattice distortion in the HEA nanodendrites contributes to their superb ethanol oxidation stability. In situ infrared absorption spectroscopy reveals that the three HEA nanodendrites mainly follow C1 pathway with C-C bond breaking to form CO followed by CO oxidation especially at a wide range of high potentials. Theoretical calculations reveal that among these HEAs, PtIrRhCoFeNiCu possesses the lowest energy barrier for C-C bond scission due to synergy among Pt/Ir/Rh and water dissociation due to synergy among Co/Fe/Ni/Cu. This work provides insights to design unique HEA nanostructures with extraordinary catalytic performances and selectivity compared to conventional nanoparticles.
开发具有高催化活性、耐久性和抗CO中毒性能的乙醇氧化电催化剂仍然是一项重大挑战。近年来，具有独特物理和化学性质的高熵合金（HEAs）受到了广泛关注。在此，通过一种简单的湿化学方法设计了一类HEA纳米枝晶。七元PtIrRhCoFeNiCu高熵合金催化剂的质量活性和比活性分别为2.13 A mg /1.05 A mg 和2.95 mA cm，相对于商业Pt/C（0.37 A mg 和0.53 mA cm）分别提高了5.76倍/2.84倍和5.57倍。值得注意的是，在进行长达100,000 s的i-t测试和1500次循环的加速耐久性测试后，分别有81.22%和68.54%的初始质量活性得以良好保留。如Pt-Pt键长增加所表明的，与晶格畸变相关的局部拉伸应变增强了乙醇吸附并降低了反应势垒。此外，HEA纳米枝晶中晶格畸变引起的滞后扩散效应有助于其卓越的乙醇氧化稳定性。原位红外吸收光谱表明，这三种HEA纳米枝晶主要遵循C1途径，即C-C键断裂形成CO，随后进行CO氧化，尤其是在很宽的高电位范围内。理论计算表明，在这些HEA中，由于Pt/Ir/Rh之间的协同作用以及Co/Fe/Ni/Cu之间的协同作用导致的水离解，PtIrRhCoFeNiCu具有最低的C-C键断裂能垒。这项工作为设计与传统纳米颗粒相比具有非凡催化性能和选择性的独特HEA纳米结构提供了思路。
