Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 206 Roger Adams Laboratory, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States.
Department of Physics, Knox College, 2 East South Street Galesburg, Illinois 61401, United States.
Inorg Chem. 2021 Apr 5;60(7):4236-4242. doi: 10.1021/acs.inorgchem.0c03298. Epub 2021 Jan 8.
It is of great research interest to understand the nanostructures contributing to the activity observed in the reduction of oxygen by non-platinum group metal (PGM) electrocatalysts in acidic media. Iron- and nitrogen-containing carbon networks are often the most studied structures, among which single-atom iron-coordinated nitrogen (FeN) moieties have often been proposed to be the structures leading to the high activity in these non-PGM electrocatalysts. Iron nanoparticles embedded within a carbon support are also formed under certain conditions as a result of the synthetic processes in making non-PGM electrocatalysts. In this study, we present a study to understand the oxygen reduction reaction (ORR) activity of prepared iron- and nitrogen-containing non-PGM electrocatalysts obtained through the pyrolysis of metal-organic framework (MOF) precursors. We studied the structure-property relationship among nanostructures made from the MOF precursor ZIF-8 under different pyrolysis conditions. Density functional theory calculations were used to explain the effect of structural moieties on the ORR activity. Our results suggest that iron-coordinated C-N structures and iron nanoparticles act synergistically to catalyze the ORR.
研究非贵金属（PGM）电催化剂在酸性介质中还原氧时起作用的纳米结构具有重要的研究意义。含铁和含氮的碳网络通常是研究最多的结构，其中单原子铁配位氮（FeN）部分经常被提出是导致这些非 PGM 电催化剂具有高活性的结构。在某些条件下，在制备非 PGM 电催化剂的合成过程中，也会形成嵌入碳载体中的铁纳米颗粒。在这项研究中，我们通过研究金属有机骨架（MOF）前体热解得到的含铁和含氮的非 PGM 电催化剂的氧还原反应（ORR）活性，来了解其性能。我们研究了不同热解条件下 ZIF-8 衍生的 MOF 前体的纳米结构之间的结构-性能关系。使用密度泛函理论计算来解释结构部分对 ORR 活性的影响。我们的结果表明，铁配位的 C-N 结构和铁纳米颗粒协同作用催化 ORR。
