The role of co-adsorbed O2 on the catalytic reduction of NO with 13C2H5OH on the surface of Pt(3 3 2)

The influence of pre-dosed O2 on the catalytic reduction of NO with 13C2H5OH on the surface of stepped Pt(3 3 2) was investigated using Fourier transform infra red reflection-absorption spectroscopy (FTIR-RAS) and thermal desorption spectroscopy (TDS). We show that the oxidation of 13C2H5OH with O2 is a very effective reaction, occurring at 150 K and giving rise to acetate. The presence of NO does not lead to any evident oxidation of 13C2H5OH irrespective of the annealing temperature. For the case of O2 + 13C2H5OH + NO co-adlayers, oxidation of 13C2H5OH also takes place at 150 K. However, no new surface species that are supposed to be an intermediate for the production of N2 are detected.The influence of O2 on the production and desorption of N2 is intimately related to both O2 and 13C2H5OH coverage. The presence of pre-dosed O2 does not greatly promote N2 desorption. In fact, N2 desorption is suppressed quantitatively with increasing O2 coverage, after which unreacted, or left-over O atoms appear and remain on steps. It is concluded that the presence of pre-dosed O2 does not play a role of activating reactants in the catalytic reduction of NO with 13C2H5OH on the surface of Pt(3 3 2).