Kinetics and mechanism of dehydration of isopropyl and sec-butyl alcohols on catalysts consisting of quartz coated by liquid phosphoric acid and mixtures of phosphoric acid and KH2PO4

Abstract

1. A pulsed Chromatographie method was used to investigate the kinetics and mechanism of dehydration of isopropyl alcohol on catalysts consisting of fused quartz coated with phosphoric acid and phosphoric acid with potassium dihydrophosphate. 2. Data on the dehydration of sec-butanol on a catalyst consisting of quartz coated with phosphoric acid have been checked and their precision improved. 3. In the experiments with catalysts without the addition of salt, the rate constant of the dehydration of secondary propyl and butyl alcohols increases proportionally to the square of the thermodynamic activity of the acid when the concentration of the phosphoric acid in the liquid phase is changed. This fact is attributed to the participation of the nonionized alcohol molecule and two molecules of phosphoric acid in the limiting stage of the reaction.