Synthesis and Catalytic Oxidation Performance of FeAPO-5 Zeolite

FeAPO 5 is synthesized hydrothermally by using tetraethylammonium hydroxide as an organic templating agent, in which crystallization is influenced by the mole ratio of the reaction mixture especially the ratio of Al∶P dispersion of reaction materials, pH value of solution, aging time, crystallization time and temperature. The products are characterized by XRD, FTIR, AA and Mssbauer. The results present that the samples possess the same framework as AlPO 4 5 molecular sieves and Fe atoms enter into the framework of the molecular sieves. Through Mssbauer spectra, it is seen that Fe is presented in two states, but they exist in the forms of FeOOH and trivalent tetrahedron. The catalytic property of FeAPO 5 is examined by the oxidation of cyclohexane. The results show that FeAPO 5 catalysts have good oxidizing activity to cyclohexane and the turnover numbers are influenced acutely by the temperature and the iron content of FeAPO 5. From 25°C to 120°C , byproducts of the reaction are less than 7%, which indicates that FeAPO 5 catalysts have good selectivity to cyclohexanol and cyclohexanone.