Role of resin-copper(II) complexes containing ethanolamines in hydrogen peroxide decomposition

Dowex-50W resins in the form of mono (mea)-, di (dea)-and tri-ethanolamine (tea)-CuII complexes have been used as potentially active catalysts for H2O2 decomposition in an aqueous medium. The rate constant (per g of dry resin) was evaluated with resins containing 2,8 and 12% divinylbenzene (DVB) crosslinkage, over the temperature range 25–40°C. The reaction was first order with respect to [H2O2] with mea for 8 and 12% DVB (50–100 mesh), second order with mea for 2% DVB (50–100 and 200–400 mesh) and third order with dea and tea for 8% DVB (50–100 mesh). The value of the rate constant (per g of dry resin) of the mea-CuII/CoII binary system was compared with that of the mea-CuII/NiII binary system. With a given degree of resin crosslinkage the activation energy increased in the sequence mea < dea < tea, which is the inverse sequence of the basic strength of the free amines. The activation parameters were calculated. Probable mechanisms were proposed for the reaction with the three ethanolamines.