Susut Ceren, Chapman George B, Samjeské Gabor, Osawa Masatoshi, Tong YuYe
Department of Chemistry, Georgetown University, 37th & O Streets, NW, Washington, DC, 20057, USA.
Phys Chem Chem Phys. 2008 Jul 7;10(25):3712-21. doi: 10.1039/b802708k. Epub 2008 May 22.
Pt nanoparticles having the same size ( approximately 10 nm) but different shapes (cubic or octahedral/tetrahedral), as determined by transmission electron microscopy, were synthesized via a polyol-based synthetic procedure. Their respective electrocatalytic activities for methanol oxidation were characterized by cyclic voltammetry and chronoamperometry in both sulfuric and perchloric acid electrolytes, which showed clear shape (surface orientation) dependences. Furthermore, the octahedral/tetrahedral Pt nanoparticles displayed an unexpectedly large enhancement in methanol electro-oxidation activity; about 3-fold increase in transient intrinsic activity and 10-fold increase in CO tolerance steady-state activity when compared to commercial Pt black. Gaseous and methanolic CO adsorption on the synthesized nanoparticles were also investigated by surface-enhanced IR absorption spectroscopy in perchloric acid electrolyte, which suggested that the different trends observed might be related to the electronic effects specific to a given ensemble of the nanofacets.
通过基于多元醇的合成方法合成了具有相同尺寸（约10纳米）但形状不同（立方或八面体/四面体）的铂纳米颗粒，其形状由透射电子显微镜确定。在硫酸和高氯酸电解质中，通过循环伏安法和计时电流法对它们各自对甲醇氧化的电催化活性进行了表征，结果显示出明显的形状（表面取向）依赖性。此外，八面体/四面体铂纳米颗粒在甲醇电氧化活性方面表现出意外的大幅增强；与商业铂黑相比，瞬态本征活性提高了约3倍，CO耐受性稳态活性提高了10倍。还通过表面增强红外吸收光谱法研究了合成纳米颗粒上气态和甲醇态CO的吸附，这表明观察到的不同趋势可能与特定纳米面集合的特定电子效应有关。
