摘要
The synthesis of surface composition-tunable Pt-based octahedral nanoalloys is key to unravel the structureproperty relationship in fuel cells. Herein, we report a facile route to prepare composition-tunable Pt Cu octahedral nanoalloys by using halogen ions(Br-or/and I-) as composition modulators. Among these Pt Cu octahedral nanoalloys,Pt59 Cu41 octahedron exhibits the highest catalytic activity and durability in alkaline solution. The specific activity/mass activity of Pt59 Cu41 octahedron is 20.25 m A cm^-2/3.24 A mg^-1 Pt,which is 6.64/5.3 times higher than commercial Pt black in 0.5 mol L^-1 CH3 OH, respectively. In the case of using ethanol(0.5 mol L^-1) as fuel source, Pt59 Cu41 octahedron shows much better catalytic activity, that is 34.84 m A cm^-2/5.58 A mg^-1 Pt for specific activity/mass activity, which is 9.16/7.34 times higher than commercial Pt black, respectively. In situ Fourier transform infrared spectroscopy is employed to detect the intermediate species and products for methanol/ethanol oxidation reaction and a plausible mechanism is proposed to explain the improved activity and durability of Pt59 Cu41 octahedron toward methanol/ethanol oxidation in alkaline medium.
本文介绍了一种以卤素离子(Br-或/和I-)为成分调变剂制备组成和应变可调的PtCu八面体纳米合金的简便方法.由于纳米合金化所产生的配位效应、协同效应和应变效应, PtCu八面体纳米合金在碱性介质中对甲醇和乙醇电氧化表现出优于商业Pt黑的催化性能.在这些PtCu八面体纳米合金中,优化的Pt59Cu41八面体纳米合金具有较高的催化活性和耐久性.对于甲醇氧化, Pt59Cu41八面体的比活性/质量活性为20.25 mAcm^-2/3.24Amg^-1Pt,分别是商业铂黑的6.64/5.3倍.对于乙醇氧化, Pt59Cu41八面体的比活性/质量活性为34.84 m A cm^-2/5.58 A mg^-1Pt,分别是商业铂黑的9.16/7.34倍.利用原位傅立叶变换红外光谱技术,对甲醇/乙醇氧化反应中的中间物种和产物进行了检测,并探讨了Pt59Cu41八面体催化活性和耐久性较好的原因,同时解释了在碱性介质中甲醇氧化耐久性优于乙醇的原因.本文对探索制备高性能的碱性甲醇/乙醇燃料电池纳米电催化剂具有一定的科学意义.
作者
Fengling Zhao
Qiang Yuan
Bin Luo
Chaozhong Li
Fang Yang
Xiaotong Yang
Zhiyou Zhou
赵凤玲;袁强;罗斌;李朝忠;杨芳;杨晓彤;周志有(Department of Chemistry,College of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Key Lab of Organic Optoelectronics&Molecular Engineering,Tsinghua University,Beijing 100084,China;State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China)
基金
supported by the National Natural Science Foundation of China (21571038 and 21361005)
the Open Fund of the Key Lab of Organic Optoelectronics & Molecular Engineering (Tsinghua University)
the Foundation for Excellent Young Scientific and Technological Talents of Guizhou Province (2019-5666)
the Special Fund for Natural Science of Guizhou University (201801)
