Abstract

We are presently investigating the emission of OH radicals by laser-induced fluorescence (LIF) in the H₂ + 1/20₂ → H₂O reaction on polycrystalline platinum. Results are obtained for emission yields of OH as functions of pressure (5-500 mTorr), temperature (950-1300 K), and O₂/H₂ ratios. The rotational temperature distribution of the desorbing OH molecules is determined, showing a significant dependence of the total pressure. The rotational temperature is only 50-75% of the surface temperature of the catalyst, i.e., the emitted OH radicals are not in thermal equilibrium when they are produced. Apparent desorption energies are also achieved. They vary from 30 to 60 kcal/mole for different O₂/H₂ ratios.

© 1986 Optical Society of America