中国科学技术大学陈乾旺团队报道了局部电荷转移揭示了Ru在碱性氢氧化反应中高电位的抗失活。相关研究成果发表在2024年6月5日出版的《美国化学会杂志》。

Ru基碱性氢氧化反应（HOR）电催化剂的活性通常在高于0.1V的电势下迅速降低（相对于可逆氢电极（RHE）），这显著限制了燃料电池的寿命。研究发现，这种现象是由高电势下Ru纳米粒子的过充电导致的O物种的过度吸收引起的。

该文中，制备了Mn₁O_x(OH)_y团簇修饰的Ru纳米颗粒(Mn₁O_x(OH)_y@Ru/C)，以促进电荷从过充电的Ru纳米粒子转移到Mn₁O_x(OH)_y团簇。Mn₁O_x(OH)_y@Ru/C在0–1.0 V的宽电势范围内表现出高的HOR活性和稳定性。此外，具有Mn₁O_x(OH)_y@Ru/C阳极的氢氧化物交换膜燃料电池提供1.731 W cm^–2的高峰值功率密度，远优于Pt/C阳极。

原位X射线吸收精细结构（XAFS）分析和密度泛函理论（DFT）计算表明，Mn₁O_x(OH)_y团簇中的Mn可以在更高的电势下从过充电的Ru中接收更多的电子，并显著减少O物种在Ru上的过吸附，从而能够在高电势下在Ru中进行HOR。

该研究为设计在高电位下没有活性衰减的碱性HOR催化剂提供了指导。

附：英文原文

Title: Local Charge Transfer Unveils Antideactivation of Ru at High Potentials for the Alkaline Hydrogen Oxidation Reaction

Author: Hongda Shi, Yang Yang, Pin Meng, Jiahe Yang, Wei Zheng, Pengcheng Wang, Yunlong Zhang, Xingyan Chen, Zhiyu Cheng, Cichang Zong, Dongdong Wang, Qianwang Chen

Issue&Volume: June 5, 2024

Abstract: The activity of Ru-based alkaline hydrogen oxidation reaction (HOR) electrocatalysts usually decreases rapidly at potentials higher than 0.1 V (vs a reversible hydrogen electrode (RHE)), which significantly limits the lifetime of fuel cells. It is found that this phenomenon is caused by the overadsorption of the O species due to the overcharging of Ru nanoparticles at high potentials. Here, Mn1Ox(OH)y clusters-modified Ru nanoparticles (Mn1Ox(OH)y@Ru/C) were prepared to promote charge transfer from overcharged Ru nanoparticles to Mn1Ox(OH)y clusters. Mn1Ox(OH)y@Ru/C exhibits high HOR activity and stability over a wide potential range of 0–1.0 V. Moreover, a hydroxide exchange membrane fuel cell with a Mn1Ox(OH)y@Ru/C anode delivers a high peak power density of 1.731 W cm–2, much superior to that of a Pt/C anode. In situ X-ray absorption fine structure (XAFS) analysis and density functional theory (DFT) calculations reveal that Mn in Mn1Ox(OH)y clusters could receive more electrons from overcharged Ru at higher potentials and significantly decrease the overadsorption of the O species on Ru, thus permitting the HOR on Ru to proceed at high potentials. This study provides guidance for the design of alkaline HOR catalysts without activity decay at high potentials.

DOI: 10.1021/jacs.4c03622

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c03622