原位XAS分析揭示的用于酸性氧还原反应的14元六氮杂大环铁配合物的高耐久性

High Durability of a 14-Membered Hexaaza Macrocyclic Fe Complex for an Acidic Oxygen Reduction Reaction Revealed by In Situ XAS Analysis.

作者信息

Ohyama Junya, Moriya Makoto, Takahama Ryo, Kamoi Kazuki, Kawashima Shin, Kojima Ryoichi, Hayakawa Teruaki, Nabae Yuta

机构信息

Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.

College of Science, Academic Institute, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.

出版信息

JACS Au. 2021 Sep 20;1(10):1798-1804. doi: 10.1021/jacsau.1c00309. eCollection 2021 Oct 25.

Nonplatinum metal (NPM) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) have been developed; however, NPM catalysts still need to be improved in terms of both their catalytic activity and durability. To overcome these problems, an Fe active site contained within a more compact ligand than conventional, porphyrinic, 16-membered ring ligands, or more specifically, a hexaaza macrocyclic ligand with a 14-membered ring (14MR), was developed. In this study, the durability of the Fe-14MR complex was compared to that of Fe phthalocyanine (FePc), which has a 16-membered ring ligand, using in situ X-ray absorption spectroscopy; demetalation of the Fe complexes was directly observed during electrochemical experiments performed under acidic ORR conditions. It was found that Fe-14MR is significantly more resistant to demetalation than FePc during the ORR.

用于质子交换膜燃料电池（PEMFC）中氧还原反应（ORR）的非铂金属（NPM）催化剂已被开发出来；然而，NPM催化剂在催化活性和耐久性方面仍有待改进。为了克服这些问题，开发了一种铁活性位点，其包含在比传统的卟啉类16元环配体更紧凑的配体中，或者更具体地说，是一种具有14元环（14MR）的六氮杂大环配体。在本研究中，使用原位X射线吸收光谱法将Fe-14MR配合物的耐久性与具有16元环配体的酞菁铁（FePc）的耐久性进行了比较；在酸性ORR条件下进行的电化学实验过程中直接观察到了铁配合物的脱金属现象。结果发现，在ORR过程中，Fe-14MR比FePc对脱金属具有显著更高的抗性。