A comparison of rotational energy accommodation in catalytically produced OD and OH radicals desorbing from a smooth Pt(111) single crystal

Rotational energy distributions of OD and OH radical reaction products desorbing from a smooth Pt(111) single crystal surface have been measured under closely similar experimental conditions by using the laser-induced fluorescence technique in conjunction with an UHV apparatus. Over the temperature ranges studied, nearly full rotational energy accommodation was observed for OD with a rotational to surface temperature ratio, T_r/T_s = 0.96 ± 0.04, and a somewhat lower ratio of 0.86 ± 0.05 was obtained for OH. For both OD and OH the spin-orbit temperatures were the same as the rotational temperatures and no preference for any lambda-doublet state was observed.