Abstract
The laser-induced fluorescence technique has been used to study OH radicals desorbed from a polycrystalline Pt foil in the H 2 + O 2 reaction. The experiments were performed under steady-state reaction conditions in the pressure range 10–100 mTorr at a catalyst temperature of 1300 K. Concentration profiles of OH radicals as a function of the distance from the catalyst were measured by imaging the fluorescence light with a diode array detector. The measurements in this pressure range support our earlier conclusion that the detected OH radicals are produced by catalytic reactions on the surface (S. Ljungström et al., Surf. Sci. 216, 63 (1989)). No evidence was found for the catalytic promotion of gas-phase reactions, as has been observed in studies of similar reactions with catalytically stabilized thermal burners at higher pressures. Analysis of the measured concentration profiles shows that the desorbed OH radicals can best be descricbed by a cos θ distribution. The effects of gas-phase collisional processes have been investigated by evaluation of the local rotational distribution of the desorbed OH radicals.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
