Activation and catalytic transformation of carbon oxygenates by uranium, yttrium and palladium complexes

Abstract

In recent years the use of renewable feedstocks, instead of fossil fuels, for the production of industrially important chemicals has drawn increasing attention. An interesting aspect of moving towards low-carbon technologies is the use of carbon dioxide as an appealing carbon source as a cheap, non-toxic and abundantly available C1 building block.

This thesis is divided in two parts in which the activation and the catalytic transformation of small molecules, such as CO and CO2, have been studied with an actinide, a rare-earth and a transition metal catalysts. An introduction examining the chemistry trends across d- and f-block is given in chapter one.

Part A: Chapter two reviews important uranium and yttrium complexes in the literature that successfully undergo small molecule activation. Boroxide ligands and their properties are introduced and selected examples are provided.

Chapter three reports the synthesis and characterisation of a new U(III) boroxide complex and its reactivity towards small molecules. The synthesis and characterisation of two different yttrium boroxide complexes is reported and the reactivity with small molecules is compared.

Part B: A very interesting use of carbon dioxide is the catalytic formation of acrylates with alkenes.

Chapter four reviews the catalytic transformation of carbon dioxide and ethene to acrylate, focusing on nickel and palladium catalyst and on the mechanism and the formation of a lactone as an intermediate species.

Chapter five describes the catalytic screening of different parameters such as catalyst precursor, ligands and temperature on the catalytic formation of acrylate using nickel and palladium catalysts.

Chapter six presents the detailed experimental methods used in part A and B.