Photooxidation of aniline on alumina with sunlight and artificial UV light

The photooxidation of aniline to azobenzene on alumina in ethanol with natural sunlight and artificial UV light (365 nm) was studied as a function of [aniline], catalyst loading, airflow rate, solvent composition, etc. The metal oxide exhibits sustainable catalytic activity. The product formation is larger with illumination at 254 nm than at 365 nm. Electron donors like triphenylphosphine, diphenylamine and hydroquinone enhance the photocatalysis. Singlet oxygen quencher, azide ion does not suppress the catalysis. The photooxidation occurs in protic and aprotic solvents. The product formation is analyzed using a kinetic model.