Simultaneous operando EPR/UV–vis/laser–Raman spectroscopy — A powerful tool for monitoring transition metal oxide catalysts during reaction

This paper represents the extended version of a short communication [Chem. Commun. (2005) 1761] in which for the first time, a setup is presented by which operando EPR, UV–vis and laser–Raman spectra as well as catalytic activity and selectivity can be recorded simultaneously during heterogeneous catalytic gas-phase reactions from the same solid catalyst under identical reaction conditions. In comparison to the separate single-technique applications, this novel triple coupling provides more comprehensive and more relevant information about the working catalytic system since problems arising from differences in reaction conditions and cell designs are avoided and a broader range of catalyst properties can be assessed. The technique has been used to study structure–function relationships in a supported V/TiO2 catalyst during oxidative dehydrogenation of propane. Benefits arising in comparison to single-technique approaches are discussed.