Liang Jiashun, Li Na, Zhao Zhonglong, Ma Liang, Wang Xiaoming, Li Shenzhou, Liu Xuan, Wang Tanyuan, Du Yaping, Lu Gang, Han Jiantao, Huang Yunhui, Su Dong, Li Qing
State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA.
Angew Chem Int Ed Engl. 2019 Oct 21;58(43):15471-15477. doi: 10.1002/anie.201908824. Epub 2019 Sep 17.
The commercialization of proton exchange membrane fuel cells (PEMFCs) relies on highly active and stable electrocatalysts for oxygen reduction reaction (ORR) in acid media. The most successful catalysts for this reaction are nanostructured Pt-alloy with a Pt-skin. The synthesis of ultrasmall and ordered L1 -PtCo nanoparticle ORR catalysts further doped with a few percent of metals (W, Ga, Zn) is reported. Compared to commercial Pt/C catalyst, the L1 -W-PtCo/C catalyst shows significant improvement in both initial activity and high-temperature stability. The L1 -W-PtCo/C catalyst achieves high activity and stability in the PEMFC after 50 000 voltage cycles at 80 °C, which is superior to the DOE 2020 targets. EXAFS analysis and density functional theory calculations reveal that W doping not only stabilizes the ordered intermetallic structure, but also tunes the Pt-Pt distances in such a way to optimize the binding energy between Pt and O intermediates on the surface.
质子交换膜燃料电池（PEMFC）的商业化依赖于用于酸性介质中氧还原反应（ORR）的高活性和稳定的电催化剂。用于该反应最成功的催化剂是具有铂表皮的纳米结构铂合金。本文报道了进一步掺杂百分之几的金属（钨、镓、锌）的超小且有序的L1 -铂钴纳米颗粒ORR催化剂的合成。与商业铂碳催化剂相比，L1 -钨-铂钴/碳催化剂在初始活性和高温稳定性方面均有显著提高。L1 -钨-铂钴/碳催化剂在80°C下经过50000次电压循环后，在PEMFC中实现了高活性和稳定性，优于美国能源部2020年的目标。扩展X射线吸收精细结构（EXAFS）分析和密度泛函理论计算表明，钨掺杂不仅稳定了有序的金属间结构，还调整了铂-铂间距，从而优化了表面铂与氧中间体之间的结合能。
