中国科学技术大学吴长征团队报道了表面阴离子促进Pt电催化剂在燃料电池中的耐CO性能。相关研究成果发表在2022年11月23日出版的《美国化学会杂志》。

铂作为电催化剂具有相当高的活性和稳定性，但在CO中毒情况下，特别是在用于实际质子交换膜燃料电池（PEMFCs）的CO残余燃料中，铂并不总是能够保持这种性能。

该文中，研究人员报告了包括铂纳米颗粒上的一系列非金属元素在内的表面阴离子导致燃料电池中电催化剂具有优异的CO耐受性。特别是，磷表面阴离子修饰的Pt（表示为P–Pt）比商业Pt/C具有10倍以上的CO耐受性增强（仅8.4%的衰减），其可以在CO中毒半细胞和全细胞中充当强大的电催化剂。此外，还提出了通用机理和原理，指出应优先选择表面阴离子以提供电子反馈，从而降低Pt表面的d带中心，成功地削弱了CO吸附并导致高耐受能力。

研究人员认为Pt表面上的表面阴离子可以为实际的PEMFCs带来强大的电催化剂，并为高性能Pt基电催化剂提供了新的见解。

附：英文原文

Title: Surface Anion Promotes Pt Electrocatalysts with High CO Tolerance in Fuel-Cell Performance

Author: Han Cheng, Jun Xia, Minghao Wang, Chun Wang, Renjie Gui, Xuemin Cao, Tianpei Zhou, Xusheng Zheng, Wangsheng Chu, HengAn Wu, Yi Xie, Changzheng Wu

Issue&Volume: November 23, 2022

Abstract: Platinum reaches considerable activity and stability as an electrocatalyst but is not always capable of maintaining such performance under CO poisoning, particularly in CO residual fuels for practical proton-exchange membrane fuel cells (PEMFCs). In this work, we report that surface anions including a series of nonmetal elements on Pt nanoparticles result in outstanding CO tolerance for electrocatalysts in fuel cells. In particular, phosphorus surface-anion-modified Pt (denoted as P–Pt) possesses more than 10-fold enhancement of CO tolerance (only 8.4% decay) than commercial Pt/C, which can serve as a robust electrocatalyst both in CO poisoning half cells and full cells. Moreover, the general mechanism and principle were proposed, stating that surface anions should be selected preferentially to offer electron feedback to downshift the d-band center for the Pt surface, successfully weakening CO adsorption and leading to high-tolerance capability. We anticipate that surface anions on a Pt surface can bring robust electrocatalysts for practical PEMFCs and offer novel insights for high-performance Pt-based electrocatalysts.

DOI: 10.1021/jacs.2c09147

Source: https://pubs.acs.org/doi/10.1021/jacs.2c09147