Electronic excitation in electron bombardment enhancement of chemical reactions

Abstract

The role of electronic excitation in the electron bombardment enhancement of surface reactivity of graphite with hydrogen has been identified. The correlation between the electron and photon enhanced reactivities of a graphite surface is consistent with electrons exciting the 4.8-eV Π-valence to Π-conduction transition responsible for photoenhanced reactivity. An electron impact study has shown that low-energy electrons excite the same low-energy transitions observed in optical studies. Secondary electrons produced by electron bombardment are of appropriate energies to excite these transitions. Similar processes are expected to be operative in other chemical systems exhibiting photoenhanced reactivity.