Operando CO Infrared Spectroscopy and On-Line Mass Spectrometry for Studying the Active Phase of IrO2 in the Catalytic CO Oxidation Reaction

We combine operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) with on-line mass spectrometry (MS) to study the correlation between oxidation state of titania-supported IrO2 catalysts (IrO2@TiO2) and their catalytic activity in prototypical CO reaction. Here, stretching vibration adsorbed COad serves as probe. DRIFTS provides information on both surface gas phase species. Partially reduced is shown be significantly more active than its fully oxidized counterpart, onset full conversion temperatures being about 50 °C lower for IrO2. By DRIFTS, this increase traced a partially catalysts, evidenced by broad IR band reaching from 2080 1800 cm−1.