Development of a zeolite encapsulated catalyst for oxidation of alkenes

Abstract

Zeolite Y was synthesized from a mixture of sodium aluminate, sodium hydroxide, sodium silicate, aluminium sulfate and water. A slurry of nucleation centers or seeds containing 13.5Na20: 1.0Al2O3: 12.5Si02: 516H20 was aged for 5 days and then added to gel. The gel component obtained was 1.9Na20: 1.0Al2O3; 6.0SiO2: 100H2O. The mixture was vigorously stirred and crystallized at 100 ℃ for 10 to 15 hours. The zeolite obtained was highly crystalline NaY with a Si/Al ratio of 2.3. The zeolite MnY was obtained by ion exchange of zeolite NaY with aqeous solution of Mn (II) ion. Manganese phthalocyanine is synthesized in the cavities of zeolite MnY using “ship in the bottle” method. The zeolite entrapped manganese complex is formed by the reaction between dicyanobenzene and manganese (II) ion which is the counter ion of zeolite framework. The zeolite entrapped manganese phthalocyanine was characterized using Fourier transformed infrared, atomic absorption and ultraviolet spectrometers. The stability of zeolite Y is confirmed by X-ray diffraction. The zeolite entrapped complex is found to be a catalyst for oxidation of cyclohexene but not 1-hexene. The conditions for catalysis are studied in details for effects of oxidant, solvent, catalyst amount and time. Improvement of yield can be accomplished by carrying out the catalysis in the absence of solvent, and increasing the amount of oxidant and catalyst. Oxygen is much better oxidant than iodosobenzene.