Dynamics of the Eley-Rideal Reaction of D Atoms with H Atoms Adsorbed on Cu(111): Vibrational and Rotational State Distributions of the HD Product

Abstract

We have determined the internal-state distribution for the HD product of the reaction of gas-phase D atoms with H atoms chemisorbed on Cu(111). The populations of the vibrational states $v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$, 1, 2, and 3 are comparable, while that for $v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4$ is considerably smaller, giving a mean vibrational energy of $\ensuremath{\sim}0.7$ eV. The mean rotational energy falls with increasing $v$, from $\ensuremath{\sim}0.5$ eV for $v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ to $<0.2$ eV for $v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4$, with an overall mean rotational energy of $\ensuremath{\sim}0.4$ eV. The maximum internal energy observed is $\ensuremath{\sim}2.3$ eV, consistent with the total energy available to the product. Results are compared with recent calculations.