Density functional theory study of hydrogen dissociation on Ni-doped magnesium (0001) surface

Hydrogen dissociation on Ni-doped Mg(0001) surface was studied by density functional theory calculations. Using the fixed-bond method, a dissociation barrier of 0.09 eV was obtained in contrast to 1.15 eV on a clean Mg(0001) surface reported in the literature. Electronic structure analysis shows that the decrease of the dissociation barrier comes from filling of the sigma* orbital due to the back donation through the doped Ni atom. The results indicate that the kinetics of hydrogen uptake is dramatically enhanced by doping transition metal catalysts.