Huang Minghua, Jin Yongdong, Jiang Heqing, Sun Xuping, Chen Hongjun, Liu Baifeng, Wang Erkang, Dong Shaojun
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, People's Republic of China.
J Phys Chem B. 2005 Aug 18;109(32):15264-71. doi: 10.1021/jp051612e.
Multiple-deposited Pt overlayer modified Pt nanoparticle (MD-Pt overlayer/PtNPs) films were deliberately constructed on glassy carbon electrodes through alternately multiple underpotential deposition (UPD) of Ag followed redox replacement reaction by Pt (II) cations. The linear and regular growth of the films characterized by cyclic voltammetry was observed. Atomic force spectroscopy (AFM) provides the surface morphology of the nanostructured Pt films. Rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry demonstrate that the MD-Pt overlayer/PtNPs films can catalyze an almost four-electron reduction of O(2) to H(2)O in air-saturated 0.1 M H(2)SO(4). Thus-prepared Pt films behave as novel nanostructured electrocatalysts for dioxygen reduction and hydrogen evolution reaction (HER) with enhanced electrocatalytic activities, in terms of both reduction peak potential and peak current, when compared to that of the bulk polycrystalline Pt electrode. Additionally, it is noted that after multiple replacement cycles, the electrocatalytic activities improved remarkably, although the increased amount of Pt is very low in comparison to that of pre-modified PtNPs due to the intrinsic feature of the UPD-redox replacement technique. In other words, the electrocatalytic activities could be improved markedly without using very much Pt by the technique of tailoring the catalytic surface. These features may provide an interesting way to produce Pt catalysts with a reliable catalytic performance as well as a reduction in cost.
通过银的多次欠电位沉积（UPD），随后与Pt（II）阳离子进行氧化还原置换反应，在玻碳电极上精心构建了多层沉积的Pt覆盖层修饰的Pt纳米颗粒（MD-Pt覆盖层/PtNPs）薄膜。观察到通过循环伏安法表征的薄膜呈线性且规则生长。原子力光谱（AFM）提供了纳米结构Pt薄膜的表面形态。旋转圆盘电极（RDE）伏安法和旋转环盘电极（RRDE）伏安法表明，MD-Pt覆盖层/PtNPs薄膜可以在空气饱和的0.1 M H₂SO₄中催化O₂几乎四电子还原为H₂O。与块状多晶Pt电极相比，如此制备的Pt薄膜在还原峰电位和峰电流方面均表现出作为用于氧还原和析氢反应（HER）的新型纳米结构电催化剂，具有增强的电催化活性。此外，值得注意的是，经过多次置换循环后，尽管由于UPD-氧化还原置换技术的固有特性，与预修饰的PtNPs相比，Pt的增加量非常低，但电催化活性仍有显著提高。换句话说，通过定制催化表面的技术，可以在不使用大量Pt的情况下显著提高电催化活性。这些特性可能提供一种有趣的方法来制备具有可靠催化性能且成本降低的Pt催化剂。
