The adsorption of NO and CO was studied on an alumina-supported platinum catalyst by in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS). The temperature range was 50-160°C and a wide variety of partial pressures was used. The band-target entropy minimization (BTEM) algorithm was applied to the DRIFTS data sets resulting in the pure component spectra of numerous species adsorbed on both the Pt (primarily a variety of Pt 0-CO and Pt2+-CO species) and alumina surface (i.e. nitrates, nitrites, bicarbonates, isocyanates) as well as gas-phase species. Thirty-one previously known species were identified as well as 6 new and previously unreported or previously unassigned spectra. The present results indicate that BTEM analysis of DRIFTS data is a very promising tool for the study of heterogeneous catalytic in situ spectroscopic data.