Raman spectroscopy and mid-infrared diffuse reflection (DR) spectroscopy have different, and highly complementary, roles in the study of catalytic reactions.
In general, Raman spectroscopy does not have enough sensitivity to allow the investigation of molecules that are adsorbed on the surface of powdered oxide catalysts, but is usually sensitive enough to allow the bulk structure of such catalysts to be characterized in situ. On the other hand, numerous previous studies have demonstrated that DR mid-infrared spectroscopy allows the reactants, intermediates, and products present on the surface of heterogeneous catalysts to be observed. In this note, we report how Raman and mid-infrared spectroscopy have been used to investigate the reactions that occur when methanol is adsorbed on the surface of copper oxide based catalysts