铂纳米颗粒生长和表面结构的理论预测

Theoretical prediction of the growth and surface structure of platinum nanoparticles

本文应用最近所建立的凝结势模型[2009物理学报58 3293;2009 J.Chem.Phys.130 164711]来确定铂纳米颗粒的表面结构,利用分子动力学模拟验证了该模型的可靠性.基于该模型所进行的第一性原理计算表明,各种形状的铂颗粒表面都以fcc的(111)面为主(约80%),(100)面形成的概率约10%,该结果与已有实验观测相符合.由于凝结势计算简单,该模型应是一种从理论上确定纳米颗粒表面结构的简便方法.

The surface structure of platinum nanoparticle in a fuel cell is the key factor to determine the catalytic efficiency.In this paper, we apply our recently established condensation potential model[2009 Acta.Phys.Sin.58 3293;2009 J.Chem.Phys.130 164711]to predict the surface structure of platinum nanoparticle,and the reliability of the model is verified by molecular dynamics simulations.By first-principles calculations based on this model,we show that for various shapes of platinum particles the surfaces are mainly composed of fcc（111） facets（about 80%）,and the ratio of（100） faces is about 10%.The results are consistent with existing experimental observations.Owing to the simplicity of the calculations,this condensation potential model is widely used to predict the surface structure of common nanoparticles.