中国科学技术大学葛君杰团队报道了单原子位置作为CO清除剂允许在PEMFC中使用粗氢。相关研究成果发表在2024年1月12日出版的《科学通报》。

纳米Pt催化剂是质子交换膜燃料电池（PEMFC）阳极的首选催化剂，但由于其对百万分之一（ppm）水平的CO的极端敏感性而受到限制，因此使用超纯H₂是确保可接受性能的先决条件。

该文中，研究人员通过使Ir/Rh单原子位点与其金属对应物协同工作来解决CO中毒问题。在1000ppm CO存在下，该催化剂不仅在电化学电池中表现出未受干扰的HOR催化行为，而且在单电池中在643mW cm^-2处表现出无与伦比的峰值功率密度，是可用的最佳PtRu/C催化剂质量活性的27倍。

中毒前实验和表面增强拉曼散射光谱（SERS）以及计算结果表明，纳米颗粒（NPs）上相邻的Ir/Rh单原子位点（SASs）的存在是这种显著催化行为的起源。单位点不仅自身表现出优异的CO氧化性能，而且可以通过提供活性OH*物种来清除吸附在近似NPs上的CO。

研究人员开辟了一条新的途径，通过单原子和纳米颗粒的协同催化来克服可怕的CO中毒问题，并为更强大的PEMFC未来铺平道路。

附：英文原文

Title: Single atom sites as CO scavenger to allow for crude hydrogen usage in PEMFC

Author: Xian Wang, Xiaolong Yang, Ying Wang, Bingbao Mei, Zhao Jin, Yang Li, Zhaoping Shi, Zheng Jiang, Changpeng Liu, Wei Xing, Junjie Ge

Issue&Volume: 2024/01/12

Abstract: Nanosized Pt catalysts are the catalyst-of-choice for proton exchange membrane fuel cell (PEMFC) anode, but are limited by their extreme sensitivity to CO in parts per million (ppm) level, thereby making the use of ultrapure H2 a prerequisite to ensure acceptable performance. Herein, we confront the CO poisoning issue by bringing the Ir/Rh single atom sites to synergistically working with their metallic counterparts. In presence of 1000 ppm CO, the catalyst represents not only undisturbed HOR catalytic behavior in electrochemical cell, but also unparalleled peak power density at 643 mW cm-2 in single cell, 27-fold in mass activity of the best PtRu/C catalysts available. Pre-poisoning experiments and surface-enhanced Raman scattering spectroscopy (SERS) and calculation results in combine suggest the presence of adjacent Ir/Rh single atom sites (SASs) to the nanoparticles (NPs) as the origin for this prominent catalytic behavior. The single sites not only exhibit superb CO oxidation performance by themselves, but can also scavenge the CO adsorbed on approximated NPs via suppling reactive OH* species. We open up a new route here to conquer the formidable CO poisoning issue through single atom and nanoparticle synergistic catalysis, and pave the way towards a more robust PEMFC future.

DOI: 10.1016/j.scib.2024.01.009

Source: https://www.sciencedirect.com/science/article/abs/pii/S2095927324000227