UV Raman spectroscopy of adsorbed SOx on γ-alumina and Pt/γ-alumina catalysts

摘要: Raman spectra of SOx adsorbed on γ-alumina and Pt/γ-alumina model catalysts have been obtained with a 244 nm spectrometer. Strong peaks in the 980–1380 cm-1 region characteristic sulfates are clearly portrayed spectra, which contrast fluorescence-dominated scans using visible excitation. Broad bands also observed 3500–3700 O–H stretch γ-alumina, belong to weakly-bound physisorbed water more strongly-bound surface hydroxyls. These features monitored as samples heated up 600°C presence nitrogen. The sulfate vary position depending whether or not is loaded platinum, hydrated, dehydrated. Platinum appears inhibit physisorption formation hydroxyls surface, evidenced by absence vibrations Pt-loaded sample. Our spectral data demonstrate that UV spectroscopy useful technique for analytical studies holds promise future situ investigations other species catalytic substrates automotive interest.