Improving PEM fuel cell catalyst activity and durability using nitrogen-doped carbon supports: observations from model Pt/HOPG systems
Improving PEM fuel cell catalyst activity and durability using nitrogen-doped carbon supports: observations from model Pt/HOPG systems
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DOI：
10.1039/b910924b
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发表时间：
2009-10
影响因子：
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通讯作者：
Yingke Zhou;Robert M. Pasquarelli;Timothy P. Holme;J. Berry;D. Ginley;R. O'Hayre
中科院分区：
文献类型：
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作者：
Yingke Zhou;Robert M. Pasquarelli;Timothy P. Holme;J. Berry;D. Ginley;R. O'Hayre
这项研究提出了明确的和令人信服的实验证据，氮掺杂的Pt/C催化剂系统的活性对甲醇氧化反应的显着有益的影响。这一证据是通过部署几何定义良好的模型催化系统组成的可调组件的Pt催化剂纳米粒子沉积到未掺杂的，Ar掺杂的，和N掺杂的高取向热解石墨（HOPG）基板。Ar-和N-掺杂通过离子束注入实现，Pt从H2 PtCl 6在HClO 4水溶液中的溶液中电沉积。利用来自扫描电子显微镜（SEM）和催化活性的水性电化学分析的形态来检查与未掺杂和Ar掺杂的对照样品相比N掺杂的效果。结果有力地支持了将氮掺杂到石墨载体中显著影响覆盖的Pt纳米颗粒的形态和行为的理论。特别地，观察到氮掺杂导致平均Pt纳米颗粒尺寸的显著降低，Pt纳米颗粒分散的增加，以及甲醇氧化的催化活性和耐久性的显著增加。在这里展示的模型催化系统代表了一个多功能的平台，研究催化剂载体的相互作用，在电催化相关的纳米粒子系统。
This study presents clear and compelling experimental evidence for the significant beneficial effects of nitrogen-doping on the activity of Pt/C catalyst systems for the methanol oxidation reaction. This evidence is obtained through the deployment of geometrically well-defined model catalytic systems consisting of tunable assemblies of Pt catalyst nanoparticles deposited onto undoped, Ar-doped, and N-doped highly oriented pyrolytic graphite (HOPG) substrates. Both Ar- and N-doping were achieved via ion beam implantation, and Pt was electrodeposited from solutions of H2PtCl6 in aqueous HClO4. Morphology from scanning electron microscopy (SEM) and aqueous electrochemical analysis of catalytic activity was utilized to examine the effect of N-doping compared to the undoped and Ar-doped control samples. The results strongly support the theory that doping nitrogen into a graphite support significantly affects both the morphology and the behavior of the overlying Pt nanoparticles. In particular, nitrogen-doping was observed to cause a significant decrease in the average Pt nanoparticle size, an increase in the Pt nanoparticle dispersion, and a significant increase in catalytic activity and durability for methanol oxidation. The model catalytic systems demonstrated here represent a versatile platform to study catalyst-support interactions in electrocatalytically relevant nanoparticle systems.