Photoinduced oxidative transformation of diphenylamine on Al2O3 with enhancement by ZnO synergism

Diphenylamine (DPA) in ethanol on the surface of Al2O3 undergoes light-induced oxidative transformation affording N-phenyl-p-benzoquinonimine (PBQ). The photoinduced transformation on Al2O3 enhances with [DPA], Al2O3-loading, airflow rate and photon flux. The formation of PBQ on Al2O3 is larger under UV-C light than under UV-A light. The Al2O3 surface does not lose it activity on reuse. The mechanism of photoinduced oxidative transformation of DPA on Al2O3 has been discussed with appropriate kinetic law. ZnO enhances the UV light-induced transformation of DPA on Al2O3 indicating synergism.