基于分子模拟的HT-PEMFC阴极反应路径及温度影响

发布时间：2018-03-21 07:26

本文选题：PEM　切入点：燃料电池　出处：《沈阳建筑大学学报(自然科学版)》2017年06期 　论文类型：期刊论文

【摘要】：目的研究高温质子交换膜(HT-PEM)燃料电池阴极氧还原反应特性,分析不同温度对反应系统能量、键长、键角和反应粒子运动速度的变化规律.方法建立HT-PEM燃料电池阴极催化剂Pt(1 1 1)表面及氧分子模型,运用分子动力学原理,根据密度泛函理论和第一性原理,模拟HT-PEM燃料电池阴极氧分子在催化剂Pt(1 1 1)表面的吸附和4个氢离子依次与氧分子反应等过程.结果氧分子的吸附和第1个氢离子与氧分子反应的时间最长;反应生成物水分子的键长为0.099 nm,H-O-H键角为104.5°,与实际测量值相符.结论各步反应中,键长达到平衡需要的时间比键角达到平衡需要的时间短;随着温度的提高,各个反应粒子运动速度加快,系统能量达到平衡时需要的时间缩短,导致电化学反应速度提高.
[Abstract]:Objective to study the cathodic oxygen reduction characteristics of high temperature proton exchange membrane (HT-PEM) fuel cells and analyze the effects of different temperatures on the energy and bond length of the reaction system. Methods the surface and oxygen molecular models of HT-PEM fuel cell cathode catalyst Pt(1 11) were established. According to the density functional theory and the first principle, the molecular dynamics principle was used. The adsorption of cathode oxygen molecules on the surface of HT-PEM fuel cell and the reaction of four hydrogen ions with oxygen molecules were simulated. The results showed that the adsorption of oxygen molecules and the reaction of the first hydrogen ions with oxygen molecules took the longest time. The bond length of water molecule is 0.099 nm ~ (-1) H ~ (-O-H) bond angle is 104.5 掳, which is consistent with the measured value. Conclusion in each step reaction, the time needed to achieve equilibrium is shorter than that of bond angle, and with the increase of temperature, the time needed to achieve equilibrium is shorter. The moving speed of each reaction particle is accelerated, and the time required for the system energy balance is shortened, which leads to the increase of the electrochemical reaction speed.
【作者单位】：沈阳建筑大学交通工程学院;沈阳建筑大学机械工程学院;
【基金】：国家自然科学基金项目(51476107) 辽宁省科技厅项目(2015020627,LZ2015062)
【分类号】：TM911.4

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