We examine the recombination and desorption of hydrogen from an aluminum(lll) surface focusing on desorption processes that lead to the formation of dihydrogen and aluminum hydride (presumably alane). In; addition to simple temperature-programmed reaction spectroscopy (TPRS), we examine the perturbations. which occur to the desorption kinetics of these species as a result of the energy transfer due to collisions of a xenon beam at 1.6, 2.8, and 3.6 eV with a hydrogen covered surface. Whereas the recombinative desorption of dihydrogen from an Al(111) surface nominally follows an unusual zero-order rate law, bombardment of a hydrogen-covered surface with an energetic xenon atom leads to a kinetic profile more closely modeled by a higher reaction order. It also was found that upon exposure to the beam, the peak area (and thus the desorption yield) for the Hz desorption was reduced 5-25% depending on the length of exposure whereas for the aluminum hydride the percent reduction ranged from 10-80%. This suggests that both a stimulated etching and a change in state result from the beam exposure. We present evidence that suggests that the initial state of the bound hydrogen may involve at least in part a subsurface occupation.