Title

PHOTOCATALYSIS BY ZINC PHTHALOCYANINE ON ZEOLITES AND POISONING STUDIES OF FLUID CRACKING CATALYSTS

Date of Completion

January 1985

Keywords

Chemistry, Inorganic

Degree

Ph.D.

Abstract

Zinc phthalocyanine deposited on a zeolite support is used as a sensitizer in the photoreduction of methyl viologen dication to the methyl viologen radical cation. The zeolite support is the dispersant material used to eliminate zinc phthalocyanine intermolecular self-quenching of the excited state. Catalytic production of methyl viologen radical is achieved when ethylenediaminetetraacetic acid is used to reduce the zinc phthalocyanine cation to the neutral species. Evidence is presented which suggests that the zinc phthalocyanine is sorbed on the zeolite surface resulting in a species which has properties similar to those observed in zinc phthalocyanine solutions.^ The second part of this dissertation is concerned with the deactivation of high activity commercial cracking catalysts by vanadium and nickel deposits. The effects of these metals on the catalytic properties of the catalyst are studied using surface area, pore volume distribution, X-ray analysis, fluorescence spectra, lifetime experiments, and microactivity testing. Results show that loadings of 3% nickel have little effect on the surface properties and the activity of the catalyst for gas oil conversion. Nickel, however, has detrimental effects on the catalyst's selectivity. In contrast, 2% vanadium has disastrous effects on the activity of the catalyst, bonding to the surface and destroying its crystallinity. The luminescence spectra of the above fluid cracking catalysts show that there is movement of the nickel species on the surface. Vanadium loadings, on the other hand, give rise to a new luminescent species which is attributed to surface V(,2)O(,5) species sensitive to catalyst treatment. ^