Mechanistic Aspects for the Oxidation of Ethylene Glycol by Potassium Bromate in Presence of Sodium Hydroxide Catalyzed by Chloro Complex of Ru(III) in its Nano Concentration Range as Homogeneous Catalyst: A Kinetic Approach

摘要

The present paper deals with the kinetics and mechanism of Ru(III) catalyzed oxidation of Ethylene glycol in an alkaline solution of KBrO3 carried out in the temperature range 30-45℃.Mercuric acetate has been used as a scavenger for Br ion formed in the reaction mixture to prevent parallel oxidation by bromine. First order kinetics with respect to each [KBrO3] and [Ru(III) chloride] was observed in the oxidation of Ethylene glycol. The reaction shows zeroth order with respect to Ethylene glycol and [OH~-], whereas a negative effect is observed for [Cl~-]. Negligible effect of mercuric acetate and ionic strength of the medium has been observed The reactive species of Ru(III) in alkaline medium is [RuCl2(H2O)3(OH)]. A suitable mechanism in conformity with the kinetic observation has been proposed.The various activation parameters such as energy of activation (ΔE*), the Arrhenius factor (A), entropy of activation ("S*) etc, were calculated from the rate measurements at 30, 35, 40 and 45 ℃.The rate has been derived on the basis of obtained data.