Abstraction of D chemisorbed on graphite (0001) with gaseous H atoms

The kinetics of HD formation during admission of H atoms to D covered HOPG surfaces was measured at 150 K as a function of the initial D coverage. The phenomenology of the HD kinetics is as expected for an Eley-Rideal reaction or hot-atom reaction scenario with preference for reaction over sticking for hot atoms. It can be described by an abstraction cross-section, which varies between 17 (low coverage) and 4 A 2 (high coverage). The large abstraction cross-section at low coverages is in accordance with a steering effect of the adsorbed D on the incoming H as predicted by theory.