Photodissociation of Phosgene on Pd(111) at 193 nm

Article abstract of DOI:10.1021/j100176a073

The UV photodissociation of phosgene (Cl2CO) on Pd(111) has been studied by isothermal mass spectrometry during irradiation and by temperature-programmed desorption and X-ray photoelectron spectroscopy following irradiation.Phosgene, which adsorbs reversibly on Pd(111) at 110 K, undergoes photodissociation when irradiated with 6.4-eV photons, resulting in the evolution of CO and retention of chlorine adatoms.Photolysis rates have been monitored as a function of photon flux and, using polarized light, as a function of incident angle.The initial photodissociation crosssection is (5.3 +/- 0.8) x 10^-18 cm², higher than the gas-phase absorption cross section.The angular response of the photolysis yield is interpreted using a mechanism driven by photoexcited substrate electrons.