Energetics of hydrogen coverage on group VIII transition metal surfaces and a kinetic model for adsorption/desorption.

We determined the binding energy of hydrogen to the closest packed surface for all nine group VIII transition metals as a function of surface coverage using quantum mechanics (density functional theory with the generalized gradient approximation) with periodic boundary conditions. The study provides a systematic comparison of the most stable surfaces of the nine group VIII transition metals, leading to results consistent with available surface science studies. We then use these to develop a simple thermodynamic model useful in estimating the surface coverage under typical heterogeneous catalysis conditions and compare these results to temperature programmed desorption experiments.