Tang Zhicheng, Geng Dongsheng, Lu Gongxuan
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
J Colloid Interface Sci. 2005 Jul 1;287(1):159-66. doi: 10.1016/j.jcis.2005.01.096.
Using polyvinylpyrrolidone (PVP) as a stabilizing agent, stable colloidal solutions of platinum nanoparticles of different size distributions have been prepared by reducing H2PtCl6 with hydrogen. The UV-vis adsorption peaks at 258 nm due to the adsorption of Pt(IV) species disappear completely, indicating that the Pt(IV) species has been used up and colloidal Pt has been formed. The electrodes have been prepared from aqueous Pt colloids and glassy carbon (GC). The effect of platinum particle size of Pt/GC catalyst electrode on the electrocatalytic oxidation of carbon monoxide has been investigated. The voltammetry shows that a higher potential is needed for the oxidation of absorbed carbon monoxide with a decrease of the platinum particle size for particle sizes larger than 1 nm. But for particle sizes smaller than 1 nm, the potential remains constant while the activity decreases with decreasing the size. The snowlike, well-dispersed, and highly ordered platinum nanoparticles demonstrate high activity in the oxidation reaction of carbon monoxide. The reason may be due to the geometric structure of platinum nanoparticles.
以聚乙烯吡咯烷酮（PVP）作为稳定剂，通过氢气还原六氯合铂酸（H2PtCl6）制备了具有不同尺寸分布的稳定铂纳米颗粒胶体溶液。由于Pt(IV)物种的吸附，在258 nm处的紫外可见吸收峰完全消失，这表明Pt(IV)物种已被耗尽且形成了胶体铂。电极由水性铂胶体和玻碳（GC）制备而成。研究了Pt/GC催化剂电极上铂颗粒尺寸对一氧化碳电催化氧化的影响。伏安法表明，对于粒径大于1 nm的情况，随着铂颗粒尺寸减小，吸附的一氧化碳氧化需要更高的电位。但对于粒径小于1 nm的情况，电位保持恒定，而活性随尺寸减小而降低。雪花状、分散良好且高度有序的铂纳米颗粒在一氧化碳氧化反应中表现出高活性。原因可能是铂纳米颗粒的几何结构。
