Development of accelerated first-principle molecular dynamics program and its applications to the ultrafine metal particle catalysts

开发高性能、高选择性的新型催化剂是建立与环境协调的新体系的关键技术。然而，从自然资源中贵金属稀缺的角度来看，传统的负载型贵金属催化剂存在严重的问题。以实现环境催化剂在发展中国家的普及，实现环境保护。开发由廉价的元素组成的具有更高性能的新型催化剂是迫切需要的。因此，有必要揭示催化剂的原子结构和电子态，以及催化剂上的反应机理。为了从理论上对它们进行研究，第一原理分子动力学方法引起了人们的极大关注。由于真正的催化剂具有复杂的原子结构，并且由各种元素组成。加速第一原理分子动力学PR-…的发展迫切需要更多的公克。本研究开发了一种新型的加速量子化学分子动力学程序，并将其应用于各种负载型金属催化剂体系。该程序的基本思想是用量子化学分子动力学计算催化剂的活性物种，而用经典分子动力学方法处理除活性中心以外的其他区域。并与第一性原理密度泛函方法的计算结果进行了比较，验证了该程序的有效性。例如，研究了氢分子在Pd(111)表面的活化。在该计算中，H2分子及其吸附位置用量子化学分子动力学方法计算，而Pd表面的其他区域用经典分子动力学方法模拟。我们成功地观察到了氢在Pd(111)表面上的活化动力学。由于没有考虑电子转移，传统的经典分子动力学方法不能再现上述活化过程。另一方面，第一原理分子动力学需要无限长的计算时间。最后，我们得出结论，我们新开发的加速量子化学分子动力学程序对于模拟复杂催化剂表面的各种催化反应是有效和高效的。我们将进一步将我们的程序应用于各种复杂的固体表面系统，以实现有效的催化剂设计。较少

The development of new catalysts with high performance and selectivity is a key technology to establish novel system in harmony with environment. The conventional supported precious metal catalysts have, however, serious problems from the viewpoint of the scarcity of precious metals in the natural resources. in order to realize the popularization of the environmental catalysts in the developing country and to accomplish the environmental preservations. the development of novel catalysts which consist of cheaper elements and have higher performance is desired. Thus, it is necessary to reveal the atomic structures and the electronic states of catalysts and the reaction mechanism on catalysts. In order to investigate them theoretically, the first-principle molecuar dynamics method has attracted much attention. Since the real catalysts possess the complicated atomic structures and consist of various kinds of elements. the development of the accelerated first-principle molecular dynamics pr … More ogram is of urgent necessity. In this study, the novel accelerated quantum chemical molecular dynamics program has been developed and applied to various supported metal catalysts systems. The basic idea of this program is that the active species of catalysts is calculated by quantum chemical molecular dynamics but the other region except the active site is treated by classical molecular dynamics. The validity of this program was investigated by comparing with the results obtained by first-principles, density functional (DF), method. For example, the activation of hydrogen molecule on Pd(111) surface was studied. In this calculation, H2 molecule and its adsorption site were calculated by quantum chemical molecular dynamics method but the other region of Pd surface was simulated by classical molecular dynamics. We succeeded in observing the dynamics of H2 activation on Pd(111) surface. The conventional classical molecular dynamics method can not reproduce the above activation process because the electron transfer is not considered. On the other hand, the first-principle molecular dynamics requires infinite long computational time. Finally, we concluded that our newly developed accelerated quantum chemical molecular dynamics program is effective and efficient to simulate the various catalytic reactions on complicated catalyst surfaces. We will further apply our program to various complicated solid surface systems to realize effective catalyst design. Less