Catalytic autoxidation of chemical contaminants by hybrid complexes of cobalt(II) phthalocyanine

Abstract

Cobalt(II) tetraaminophthalocyanine (Co^(II)TAP) and cobalt(II) tetrasulfophthalocyanine (Co^(II)TSP) were linked to the surfaces of a chemically modified silica gel, a functionalized TiO_2, and an amino-substituted macroporous copolymer. The hybrid catalysts were found to have catalytic activity for the aqueous-phase oxidation of hydrazine, hydrogen sulfide, sulfur dioxide, and thiols by molecular oxygen. In general, the hybrid catalysts exhibited longer catalytic lifetimes than their homogeneous analogues. In most cases, attachment of the catalytic complexes to the solid supports resulted in reduced catalytic activity; however, in selected cases, the hybrid catalysts were more active than their homogeneous analogues. The effective diffusivity for SO_3^(2-) within macroporous polystyrene/divinylbenzene beads was found experimentally to be 2.6 X 10^(-6) cm^2 s^(1-). The observed catalytic activity has been interpreted within the framework of a kinetic model with mass-transport limitations.

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