Hydrogen-assisted scalable preparation of ultrathin Pt shells onto surfactant-free and uniform Pd nanoparticles for highly efficient oxygen reduction reaction in practical fuel cells  

作　　者：Liuxuan Luo Cehuang Fu Aiming Wu Zechao Zhuang Fengjuan Zhu Fangling Jiang Shuiyun Shen Xiyang Cai Qi Kang Zhifeng Zheng Chenyi Hu Jiewei Yin Guofeng Xia Junliang Zhang 

机构地区：[1]Institute of Fuel Cells,Key Laboratory for Power Machinery and Engineering of MOE,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [2]Department of Chemistry,Tsinghua University,Beijing 100084,China [3]The State Key Lab of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 201899,China [4]Department of Polymer Science and Engineering,Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Nano Research》2022年第3期1892-1900,共9页纳米研究（英文版）

基　　金：the National Natural Science Foundation of China(No.21975157);the China Postdoctoral Science Foundation(No.2021M692062);the Science and Technology Commission of Shanghai Municipality(No.20511104004).

摘　　要：Concentrating active Pt atoms in the outer layers of electrocatalysts is a very effective approach to greatly reduce the Pt loading without compromising the electrocatalytic performance and the total electrochemically active surface area(ECSA)for the oxygen reduction reaction(ORR)in hydrogen-based proton-exchange membrane fuel cells.Accordingly,a facile,low-cost,and hydrogen-assisted two-step method is developed in this work,to massively prepare carbon-supported uniform,small-sized,and surfactant-free Pd nanoparticles(NPs)with ultrathin~3-atomic-layer Pt shells(Pd@Pt_(3L) NPs/C).Comprehensive physicochemical characterizations,electrochemical analyses,fuel cell tests,and density functional theory calculations reveal that,benefiting from the ultrathin Pt-shell nanostructure as well as the resulting ligand and geometric effects,Pd@Pt_(3L) NPs/C exhibits not only significantly enhanced ECSA,electrocatalytic activity,and noble-metal(NM)utilization compared to commercial Pt/C,showing 81.24 m^(2)/gPt,0.710 mA/cm^(2),and 352/577 mA/mgNM/Pt in ECSA,area-,and NM-/Pt-mass-specific activity,respectively;but also a much better electrochemical stability during the 10,000-cycle accelerated degradation test.More importantly,the corresponding 25-cm^(2) H2-air/O_(2) fuel cell with the low cathodic Pt loading of~0.152 mgPt/cm^(2)geo achieves the high power density of 0.962/1.261 W/cm^(2)geo at the current density of only 1,600 mA/cm^(2)geo,which is much higher than that for the commercial Pt/C.This work not only develops a high-performance and practical Pt-based ORR electrocatalyst,but also provides a scalable preparation method for fabricating the ultrathin Pt-shell nanostructure,which can be further expanded to other metal shells for other energy-conversion applications.

关 键 词：PALLADIUM platinum oxygen reduction reaction core@shell nanostructure scalable preparation proton-exchange membrane fuel cell 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O643.36[理学—物理化学]