STICKING AND DISPLACEMENT CHANNELS IN THE COG-2(O)PT(111) REACTION/

A molecular beam of CO, impinging on a Pt surface saturated with molec ular oxygen, causes displacement of O-2 molecules into the gas phase. The kinetics of the displacement and associated CO sticking have been measured for CO kinetic energies in the range 0.06-1.83 eV. At low kin etic energies the main displacement channel is associated with the sti cking of CO, which by dynamic energy and momentum transfer causes O-2 molecules to leave the surface, with a probability of 0.09 per stuck C O molecule. At the highest CO kinetic energies an additional displacem ent channel is appearing, namely inelastic (non-sticking) scattering o f CO molecules, which deposit enough energy to displace adsorbed O-2 i nto the gas phase.