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.

在这个子项目中，我们将研究纳米多孔金的形态和表面成分如何影响电催化反应和内部传质条件。在执行潜在的程序期间或在高温下储存期间，纳米多孔金的韧带粗化。这改变了使用过程中的质量传输条件和可用表面积。粗化过程的时间进程可以受到纳米多孔材料表面处的吸附物的影响。这种吸附层对材料的催化活性有影响。在这个子项目中，我们研究了在不同的实验条件下，如电化学电位程序和温度下，粗化过程的时间过程。我们着重于电化学方法来确定内表面积和有效扩散系数内的纳米多孔金。这些方法在不从电化学电池中取出样品的情况下是适用的。将结果与使用扫描电子显微镜的选定测量值相关联。此外，我们研究了如何加入专门吸附阴离子和形成单层的外来金属通过欠电位沉积将改变粗化过程的动力学。在第二种方法中，我们研究了表面氧化物和表面结合的反应中间体的量使用表面询问模式的扫描电化学显微镜和互补的非原位光谱技术，主要是X射线光电子能谱（XPS）。然后，我们将研究，如何通过低电位沉积获得的外来金属单层将改变表面氧化物和反应中间体的量作为一个功能的应用potential.From由此获得的见解，我们想设计的方法，有效地修改纳米多孔金作为电催化剂的甲醇氧化反应，已被选为模型反应。将电催化实验的结果与液相和气相中分子氧对甲醇的氧化进行比较。