Absolute reactive cross sections for the reaction OH+CO→H+CO 2

Abstract

Using laser photolysis and vacuum-UV laser-induced fluorescence “pump-and-probe” technique, the microscopic dynamics of the reaction OH+CO→H+CO 2 was studied at different center of mass energies. Translationally excited OH radicals were generated by laser photolysis of H 2 O 2 at a wavelength of 248 nm and 193 nm, and the nascent H atoms produced in the reaction of OH with room temperature CO molecules were detected under single collision conditions by vacuum-UV laser-induced fluorescence at the Lyman-α transition. With a calibration method using H 2 S (248 nm) and HCl (193 nm) photolysis as a source of well-defined H atom concentrations, the following absolute reaction cross sections were measured: δ R (0.82 eV)=(0.3±0.1) 2 and δ R (1.13 eV)=(1.2±0.3) 2 . The experimental results are compared with full-dimensional (6D) quasiclassical trajectory studies carried out using a global potential energy surface, derived from ab initio calculations.