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Ion Exchangers as catalysts I. Catalytic decomposition of hydrogen peroxide in presence of Dowex 50 W resin in the form of ethylamine-copper(II) complex ion in aqueous medium

Research paper by Mohamed Y. El-Sheikh, Abdel-Fatah M. Habib, Fathy M. Ashmawy, Ali H. Gemeay, Ahmed B. Zaki

Indexed on: 01 Apr '88Published on: 01 Apr '88Published in: Transition Metal Chemistry



Abstract

Dowex 50 W resin in the form of an ethylamine-Cu11 complex ion was used as potentially active catalyst for the decomposition of H2O2 in aqueous medium. The stoichiometry of the amine-Cu11 complex on the resin, determined experimentally, was found to have the total [Cu2+]: [ethylamine]=1∶4 concentration ratio. The kinetics of the decomposition was studied and the calculated rate constant (per g of dry resin) was found to decrease with increase the degree of resin crosslinking. The active species, formed as an intermediate at the beginning of the reaction, had an inhibiting effect on the reaction rate. The brown peroxo-copper complex formed as a result of H2O2 decomposition, was found to contain the catalytic active species. The order of the reaction increased with decreasing initial H2O2 concentration, a sign of a step-wise mechanism. A quantitative treatment of the decomposition of H2O2 was provided in terms of activation parameters.