Electrocatalysis and transport in nanoporous gold

纳米多孔金的电催化和传输

• 批准号: 269855580
• 负责人: Professor Dr. Gunther Wittstock
• 金额: --
• 依托单位: Institut für Chemie (IfC)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/269855580?language=en
• 关键词: Electrocatalysis; transport; nanoporous; gold

In this sub-project we will investigate how morphology and surface composition of nanoporous gold influences electrocatalytic reactions and internal mass transport conditions. During the execution of potential programme or during storage at elevated temperatures the ligaments of nanoporous gold coarsen. This changes mass transport condition and available surface area during the use. The time course of the coarsening process can be influenced by adsorbates at the surface of the nanoporous material. Such adlayers have an influence on the catalytic activity of the material.In this sub-project we investigate which time course the coarsening process flows under different experimental conditions such as electrochemical potential programs and temperature. We focus on the electrochemical methods to determine the internal surface area and the effective diffusion coefficient inside the nanoporous gold. These methods are applicable without removal of the sample from the electrochemical cell. The results will be correlated to selected measurements using scanning electron microscopy. Furthermore, we investigate how the addition of specifically adsorbing anions and the formation of monolayers of foreign metals by under-potential deposition will change the kinetics of the coarsening process.In a second approach we study the amount of surface oxides and surface-bound reaction intermediates using the surface interrogation mode of scanning electrochemical microscopy and complementary ex-situ spectroscopic techniques, mainly x-ray photoelectron spectroscopy (XPS). We will then study, how monolayer of foreign metal obtained by under-potential deposition will change the amount of surface oxides and reaction intermediates as a function of applied potential.From the thus obtained insights we would like to devise ways for effective modification of nanoporous gold as electrocatalyst for methanol oxidation reaction that has been selected as the model reaction. The results of the electrocatalytic experiments will be compared to the oxidation of methanol by molecular oxygen in liquid phase and in gas phase.

在此子项目中，我们将研究纳米孔金的形态和表面组成如何影响电催化反应和内部质量传输条件。在执行潜在程序或在升高温度下存储期间，纳米孔金的韧带。这种情况会改变质量运输状况和可用表面积。变形过程的时间过程可能会受到纳米多孔材料表面的吸附物的影响。这样的adlayer对材料的催化活性有影响。在此子项目中，我们研究了在不同的实验条件下的时间流动，例如电化学潜在程序和温度。我们关注的电化学方法来确定内部表面积和纳米黄金内部的有效扩散系数。这些方法适用于无需从电化学细胞中去除样品的情况下。结果将与使用扫描电子显微镜相关的测量结果相关。 Furthermore, we investigate how the addition of specifically adsorbing anions and the formation of monolayers of foreign metals by under-potential deposition will change the kinetics of the coarsening process.In a second approach we study the amount of surface oxides and surface-bound reaction intermediates using the surface interrogation mode of scanning electrochemical microscopy and complementary ex-situ spectroscopic techniques, mainly x-ray光电子光谱学（XPS）。然后，我们将研究如何通过应用电位来改变表面氧化物和反应中间体的量如何，从而将纳米孔金作为电载体的有效修饰作为甲醇氧化反应的电催化剂，从而使纳米孔金的电催化剂有效地修改作为模型反应的甲醇氧化反应。电催化实验的结果将与通过液相和气相中分子氧对甲醇的氧化进行比较。