MS-FTIR reduction stage study of NSR catalysts

A FTIR “home-made” cell is used to study the evolution of surface species and gas phase coupled with a mass-spectrometer (MS) for time-resolved analysis in static and dynamic conditions in order to gain further information about the variables that influence the mechanism of reduction of NOx stored. A preliminary IR study with simultaneous gas and surface spectra of Pt-Ba-Al2O3 and free-Pt catalysts implies that the platinum is necessary for the regeneration in the appropriate temperature range (200–400 °C). The use of different reducing gases (H2, C3H6 or C3H8) shows that the distribution of reduction products and the temperature reaction window are correlated with the reducing molecule. Secondly, an operando MS-FTIR technique permits us to compare a Pt-Ba-Al2O3 and Pt-K-Al2O3 catalysts under flow conditions during a complete NSR cycle, showing that barium containing catalyst allows better NSR performance.