Abstract

Research into alternative energy vectors is crucial for the future of our planet and society because it addresses two pressing challenges: environmental sustainability and energy security. Hydrogen economy is one of the most promising directions, however the two major problems yet to be solved are the “green” production of hydrogen and efficient hydrogen storage solutions. The problem of hydrogen storage is aimed to be addressed in this thesis.

Our approach to solving this problem is to utilize the interactions between Fe-NHC (N-Heterocyclic Carbene) complexes and H2 to enable reversible capture and storage by manipulating the highly tuneable steric and electronic properties of Fe-NHC species.

The series of imidazolium pro-ligands with various combinations of two N-alkyl substituents on the imidazole ring (methyl to butyl, including straight and branched chain isomers) was prepared, and the corresponding Fe-NHC complexes were synthesised by reacting imidazolium salts with K[HFe(CO)4].

The reactivity of resultant Fe-NHC complexes towards hydrogen gas was then investigated, and the results were discussed and compared to literature.

It is anticipated that the outcomes of this work will enable and direct future developments into novel ligands for the purpose of hydrogen storage and activation.