Resonant Raman-scattering measurements of trichloroethene in a thermal boundary layer

Concentration profiles of trichloroethene were measured in a boundary-layer flow over a heated ceramic surface. Raman scattering was excited with the fifth harmonic of a Nd:YAG laser at 213 nm. This wavelength took advantage of a resonance in the trichioroethene molecule to significantly enhance the C₂HCl₃ scattering cross section. The resonant Raman system was calibrated in a heated flow. The optical system was optimized so that measurements could be obtained close to the solid surface, normally a significant challenge for a spontaneous Raman-scattering setup. Measured concentrations indicated the lack of catalytic activity on a bare alumina surface. However, the results showed that a surface that was coated with Cr₂O₃-based zeolite was catalytically active.