催化剂Pt作用下氧气和质子还原反应分析

The Analysis of Oxygen Reduction Reaction With Proton Based on Catalysis of Pt

氧气在质子交换膜(PEM)燃料电池阴极的还原反应特性对电池性能有重要影响。本文通过建立电催化剂Pt表面的氧吸附模型,及氢与氧在Pt表面进行的氧化还原反应模型,运用分子动力学方法模拟研究了氢原子与氧在Pt表面的反应机理,分析了温度对氧气还原反应特性的影响。研究发现,氢原子和氧原子在Pt表面初次吸附是整个氧气还原反应的控制步骤;随着温度升高,氧气还原反应的速度加快,但温度不影响氧气还原反应各个步骤中的产物结构。研究结果对加强理解PEM燃料电池反应机理,推动燃料电池的应用具有重要意义。

Oxygen plays an important role on Proton Exchange Membrane（PEM） fuel cell cathode reduction reaction.In this paper,oxygen adsorption model on catalyst Pt and the redox reaction model of hydrogen and oxygen on the surface of Pt are developed to study the reaction mechanism of hydrogen and oxygen in the Pt surface based on molecular dynamics simulation method.Analysis of the effect of temperature on the characteristics of oxygen reduction reaction is performed.The research results show that the first adsorption on the Pt surface for the hydrogen and oxygen atoms is the control step of the oxygen reduction reaction;with the increase of temperature,the oxygen reduction reaction becomes faster,but the temperature does not affect the structure of the reduction product in each step.These results are very helpful in the understanding of PEM fuel cell reaction mechanism and promote the application of PEM fuel cell.