Probing powder supported catalysts with sum frequency spectroscopy

We report the first observation of sum frequency generation (SFG) from a high surface area metal containing catalyst. In this study, total internal reflection (TIR)-SFG has been used to probe the interface between a 5 wt% Pt/Al2O3 catalyst and a carbon monoxide (CO) containing gas phase. We also offer a comparison of this catalyst with CO adsorbed on a Pt thin film and with the attenuated total refection-IR (ATR-IR) spectrum. Vibrational features associated with linearly bound CO to the surface of the Pt are observed. Transient CO adsorption/desoption phenomena are also studied.