Kinetic analysis of homogeneous catalytic reactions

Abstract

Reaction progress kinetic analysis (RPKA) is a powerful tool for determining kinetic parameters of catalytic reactions. Many of the published articles that have used RPKA have employed reaction calorimetry for obtaining sufficient data to be reliable. The use of gas uptake measurements, in place of calorimetry is explored in this Thesis. Chapter 2 details the use of gas uptake measurements in establishing the order with respect to substrate and gas for the rhodium catalysed hydrogenation of 1-octene. Previous studies have used initial rate measurements to establish these orders and the reaction cycle is well known. The use of RPKA allows the same information to be established in two reactions. Chapter 3 focuses on the rhodium catalysed hydroformylation of 1-octene as it involves the reaction of one substrate with two gases. Using RPKA it is possible to determine the order in substrate and the overall order in gas, but it was found difficult to determine the order with respect to the individual gases using RPKA alone. Chapter 4 shows the palladium catalysed methoxycarbonylation of vinyl acetate. The reaction has two substrate concentrations changing simultaneously as well as a gas. This chapter shows that by careful design of experiments the orders with respect to each of these substrates and CO can be determined in minimal numbers of experiments. Chapter 5 focuses on the methoxycarbonylation of alkynes, which uses RPKA in complex multistep reactions, to establish if RPKA can be used to determine the kinetics with respect to the individual reacting components for each step. This study focuses on the methoxycarbonylation of phenylacetylene to produce methyl cinnamate as well as the methoxycarbonylation of both terminal and internal linear alkynes. These linear alkynes carbonylate to produce an α,β-unsaturated ester. The double bond is isomerised from its conjugated position along the chain to the terminal position where it is trapped and carbonylated to produce an α,ω-dieter product.