薄层电解池中铂纳米阵列电极的介观传递特性对电催化性能影响的研究

项目名称： 薄层电解池中铂纳米阵列电极的介观传递特性对电催化性能影响的研究

项目编号： No.11202124

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张丹

作者单位： 上海大学

项目金额： 26万元

中文摘要： 本项目采用铂Pt纳米有序阵列电极（燃料电池阳极），研究介观传递过程对阳极电化学催化反应的影响。在改进的薄层电解池中，通过改变微通道中的流速，改变界面附近扩散层的厚度；基于微流体力学，研究电极表面电位势对双电层内扩散场的影响；讨论阵列电极的特征尺度和分散度对输运过程的影响。并采用数值模拟的方法求解多场耦合作用下的燃料及其中间产物的浓度和扩散场的分布。将通过分析周期性纳米结构和电极电势对界面流动状态及传质增强效应的影响，实现传质与反应动力的解耦，获得近真实的本征反应动力学常数。课题还将着重研究中间产物的吸附/解吸附过程，针对Langmuir-Hinshelwood反应机理，探讨吸附/解吸附过程中由电催化系统内在噪声诱导的双稳态间的波动。以甲醇氧化反应为例，结合实验数据，实现介观传递过程与电催化反应速率、选择性和最终产物间的定量描述。所有工作将为提高低温型燃料电池的阳极性能提供理论依据。

中文关键词： 计算流体力学；介观传质；蒙特卡洛方法；低温燃料电池；铂纳米结构电极

英文摘要： In the frame of this project, the platinum nanoelectrode arrays (anode of the fuel cell ) will be used to investigate the effect of the mesoscopic transport on the anode electrocatalytic reactions. Nearby the interface between electrode and electrolyte, the thickness of the diffusion layer will be varied by adjusting the electrolyte flow velocity in an improved thin-layer flow cell. Meanwhile the influence of the electrode surface potential on the diffusion field in double layers will be systematically studied. Furthermore it will also be discussed whether the variation of the density and the size or distribution of nano-structures/particle will directly affect the transport properties. The exact concentration and the diffusion field of fuel and intermediate species near the interface will be numerically studied by coupling multi-field models in the present project. The decoupling between the mass transfer and the reaction kinetics might be achieved in order to approach the real electrocatalytic reaction kinetics constants by precisely analysing the influence of the periodic nano structures and the electrode surface potential on the flow state and the enhancement of mass transfer at the interface. This project will also focus on the processes of the intermediate species adsorption/desorption. On the basis of the

英文关键词： Computational Fluid Dynamics；Mesoscopic Mass Transfer；Monte Carlo Method；Low Temperature Fuel Cell；Pt Nanostructured Electrode