Density functional theory study on hydrogenation mechanism in catalyst-activated Mg(0001) surface

作者：Wu Guang xin; Liu Su xia; Zhang Jie yu^*; Wu Yong quan; Li Qian; Chou Kuo chih; Bao Xin hua

来源：Transactions of Nonferrous Metals Society of China, 2009, 19(2): 383-388.

DOI：10.1016/S1003-6326(08)60282-4

• magnesium alloy
• hydrogenation mechanism
• catalyst effect
• density functional theory

A small amount of Fe(3)O(4) catalyst is known to substantially improve the adsorption and desorption thermodynamics and kinetics of Mg-based materials. Using density functional theory in combination with nudged elastic band method, the dissociative chemisorptions of hydrogen on both pure and Fe-doped Mg(0001) surfaces were studied. The adsorption energy calculations show that a weakly physisorbed state above pure and Fe-doped Mg surface atoms can serve as a precursor state to dissociative chemisorption. Then, the dissociation pathway of H(2) and the relative barrier were investigated. The calculated dissociation barrier (1.08 eV) of hydrogen molecule on a pure Mg(0001) surface is in good agreement with comparable experimental and theoretical studies. For the Fe-doped Mg(0001) surface, the activated barrier decreases to 0.101 eV due to the strong interaction between the s orbital of H and the d orbital of Fe.

• 出版日期2009-4
• 单位上海大学; 北京科技大学