 Operando spectroscopy is widely applicable to heterogeneous catalysis, which is largely used in industrial chemistry.An example of operando methodology to monitor heterogeneous catalysis is the dehydrogenation of propane with molybdenum catalysts commonly used in industrial petroleum.Mo/SiO and Mo/AlO were studied with an operando setup involving EPR/UV-Vis, NMR/UV-Vis, and Raman.