| Автор | Xie Jianjun |
| Автор | Jiang Ping |
| Автор | Zhang Kaiming |
| Дата выпуска | 1994-02-07 |
| dc.description | The dissociative adsorption of a hydrogen molecule on the nickel(100) surface with point defects is investigated using the embedded-atom method (EAM). The potential-energy surfaces (PES) for H<sub>2</sub> dissociation on both perfect and imperfect Ni(100) surfaces are presented, based on total-energy calculations. it is clearly shown that as the H<sub>2</sub> approaches the Ni(100) surface along the entrance channel, the H-H bond is progressively weakened while the H-metal bonds begin to form; finally the H<sub>2</sub> is adsorbed on the surface in the form of two independent H atoms. This dissociation process is affected by the vacancy and impurity atoms existing in the Ni substrate. The activation barriers (E<sub>a</sub>) for the dissociation of H<sub>2</sub> through various pathways are calculated. The barriers for the dissociation of H<sub>2</sub> on the perfect Ni(100) surface are found to be low (about 0.08-0.09 eV. corresponding to different dissociation pathways). The existence of vacancies enhances the dissociation of H<sub>2</sub> by lowering the activation barrier height and providing more adsorption sites. However, the impurity atoms (Cu, Pd) can impede the dissociation of H<sub>2</sub> on the Ni(100) surface by increasing the activation barrier height. The adsorption heat of H<sub>2</sub> chemisorption on the contaminated Ni(100) surface is also calculated. It is found that the effects of impurities on the dissociation of H<sub>2</sub> vary with the dissociation pathways and the impurity sites. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Defect effects on H<sub>2</sub> dissociative adsorption on the Ni(100) surface |
| Тип | paper |
| DOI | 10.1088/0953-8984/6/6/024 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 6 |
| Первая страница | 1219 |
| Последняя страница | 1228 |
| Аффилиация | Xie Jianjun; CCAST World Lab., Beijing, China |
| Аффилиация | Jiang Ping; CCAST World Lab., Beijing, China |
| Аффилиация | Zhang Kaiming; CCAST World Lab., Beijing, China |
| Выпуск | 6 |
