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

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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