Molecular architectures of iron complexes for oxygen reduction catalysis-Activity enhancement by hydroxide ions coupling

• 成果类型: Article
• 署名作者: Win, Poe Ei Phyu; Yang, Jiahui; Ning, Shuwang; Huang, Xiang; Fu, Gengtao; Sun, Qiming; Xia, Xing - Hua; Wang, Jiong
• 署名单位: Soochow University - China; Nanjing Normal University; Southern University of Science & Technology; Soochow University - China; Nanjing University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10713
• DOI: 10.1073/pnas.2316553121
• 发表日期: 2024-03-12
• 关键词: electron-transfer; metal-catalysts; phthalocyanine; electrocatalysts; TRANSITION; MODEL; o-2

摘要

Developing cost- effective and high- performance electrocatalysts for oxygen reduction reaction (ORR) is critical for clean energy generation. Here, we propose an approach to the synthesis of iron phthalocyanine nanotubes (FePc NTs) as a highly active and selective electrocatalyst for ORR. The performance is significantly superior to FePc in randomly aggregated and molecularly dispersed states, as well as the commercial Pt/C catalyst. When FePc NTs are anchored on graphene, the resulting architecture shifts the ORR potentials above the redox potentials of Fe2+/(3+) sites. This does not obey the redox- mediated mechanism operative on conventional FePc with a Fe2+-N moiety serving as the active sites. Pourbaix analysis shows that the redox of Fe2+/(3+ )sites couples with HO- ions transfer, forming a HO-Fe3+-N moiety serving as the ORR active sites under the turnover condition. The chemisorption of ORR intermediates is appropriately weakened on the HO-Fe3+-N moiety compared to the Fe2+-N state and thus is intrinsically more ORR active.