Observation of two reaction pathways for water formation from hydroxyl radical covered Pt(111)

Abstract

Intense molecular beams of hydroxyl radicals produced in a supersonic corona discharge source were focused and state-selected by an electrostatic hexapole. Thermal desorption spectra from a Pt(111) surface dosed with the resulting pure beam of OD radicals showed features corresponding to D 2O and O 2 desorption. Two distinct types of adsorbed OD were observed depending on the dosing temperature. Dosing at 215 K generated a low temperature (215 K) D 2O desorption feature. Dosing at 275 K generated a high temperature (400 K) D 2O desorption feature. Possible origins of these two features are discussed.