Investigation of D(H) abstraction by means of high resolution electron energy loss spectroscopy

In this work, we study the abstraction of deuterium (D) by hydrogen (H) atoms (respectively H by D) on both perfectly crystalline and ion bombarded graphite surfaces using high resolution electron energy loss spectroscopy. On an initially defect free graphite surface, abstraction of D by H (reciprocally and reversibly H by D) is a quite efficient process at room temperature. Measurements demonstrate that the abstraction occurs almost essentially with the adsorbed atoms on “weakly” reactive sites. Reciprocally, atoms adsorbed on defects with sp3 configuration participate in a much lower extent to the abstraction mechanism. Obviously, this phenomenon always occurs when exposing a surface to an atomic hydrogen beam and illustrates the competition between sticking and molecules formation by abstraction.