A small amount of Fe3O4 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 ba...A small amount of Fe3O4 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 H2 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.展开更多
基金Project(2007AA05Z118) supported by the Hi-tech Research and Development Program of ChinaProject(50804029, 50504010) supported by the National Natural Science Foundation of China+1 种基金Project(200746) supported by Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(IRT0739) supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘A small amount of Fe3O4 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 H2 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.
