Study of dissociation barriers of H-2 on Ni(111) and Ni3Fe(111)

摘要

The minimum energy paths (MEP) of H-2 dissociation on Ni(1 1 1) and Ni3Fe(1 1 1) are calculated using density functional theory. The dissociation barrier on Ni3Fe(1 1 1) is lower by 0.09eV with respect to the barrier of 0.1 eV on Ni(1 1 1). A formula to approximate MEP is proposed and fits well the calculated MEP of H, dissociation on Ni(11 1). By this formula, the difference in the dissociation barriers can be semi-quantitatively related with the space-independent difference in atomic chemisorption energies, providing a new way to understand the Bronsted-Evans-Polanyi relationship. (c) 2007 Published by Elsevier B.V.