Al-Zoubi Talha, Zhou Yu, Yin Xi, Janicek Blanka, Sun Chengjun, Schulz Charles E, Zhang Xiaohui, Gewirth Andrew A, Huang Pinshane, Zelenay Piotr, Yang Hong
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States.
Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
J Am Chem Soc. 2020 Mar 25;142(12):5477-5481. doi: 10.1021/jacs.9b11061. Epub 2020 Mar 10.
Non-platinum group metal (non-PGM) electrocatalysts for the oxygen reduction reaction (ORR) are generally composed of iron, nitrogen, and carbon synthesized through high-temperature pyrolysis. Among the various types of precursors, metal-organic frameworks (MOFs), zeolitic imidazolate framework (ZIF)-8 in particular, have often been used in the synthesis. The pyrolysis of ZIF-8 precursor relies on the use of Zn as a sacrificial metal (SM), and the optimal processing temperatures often exceed 1000 °C to generate active non-PGM catalysts. The high pyrolysis temperature tends to result in heterogeneous active moieties ranging from Fe single atoms to nanoparticles. In this study, we present the synthesis of non-PGM catalysts using Cd as the sacrificial metal instead of Zn. By using Cd, we were able to generate active non-PGM electrocatalysts from the MOF precursors at a low pyrolysis temperature of 750 °C, which helps preserve the single atomic iron active sites.
用于氧还原反应（ORR）的非铂族金属（non-PGM）电催化剂通常由通过高温热解合成的铁、氮和碳组成。在各种类型的前驱体中，金属有机框架（MOF），特别是沸石咪唑酯框架（ZIF）-8，经常被用于合成。ZIF-8前驱体的热解依赖于使用锌作为牺牲金属（SM），并且最佳加工温度通常超过1000°C以生成活性非PGM催化剂。高热解温度往往会导致从铁单原子到纳米颗粒的活性部分不均匀。在本研究中，我们展示了使用镉代替锌作为牺牲金属来合成非PGM催化剂。通过使用镉，我们能够在750°C的低热解温度下从MOF前驱体生成活性非PGM电催化剂，这有助于保留单原子铁活性位点。
