Preface Free

This book provides an up to date review of the state of the art of catalytic reactions in ionic liquids as well as the formation of catalytic materials using ionic liquid methods. Catalytic reactions were amongst the first to be undertaken in these neoteric solvents with electrocatalytic studies being reported in the 1960s. Thereafter, there has been an explosion in the interest in this area starting with carbon–carbon bond forming reactions utilizing ionic liquids as the catalyst as well as the solvent in Friedel–Crafts, Heck and Diels–Alder reactions. From there the field moved onto study gas–liquid reactions, asymmetric processes and the conversion of biomass. A wide range of catalysts have been utilized and modified to be compatible with ionic liquid processes including homogeneous complexes, nanoparticles, supported metal heterogeneous catalysts, supported ionic liquid based catalysts, zeolites, enzymes, electrocatalysts and photocatalysts. In the vast majority of cases, the ionic liquid based processes have been compared with analogous molecular derived systems with significant advantages being demonstrated, for example, in rate, selectivity, recycle of the catalyst or work up procedures. In a number of cases, the ionic liquid based systems have enabled new reactions to be undertaken. Due to the wide range of ionic liquids available and the ability to functionalise the cation and the anion to tailor their physical and chemical properties, the field of catalysis in ionic liquids has been transformed over the last 20 years from both the perspective of novel materials synthesis as well as reactivity-selectivity profiles. The chapters provide a perspective on how ionic liquid properties can be modified by structural changes to enable the catalytic materials and processes to be controlled. In addition, the reviews provide a summary of where our understanding lies in these systems. The complex nature of the interactions involved and the potential these systems have to change many industrial processes provide significant opportunities for future study. This is particularly true in the translation of the technologies under study from the bench scale to pilot and full scale industrial utilization where the recovery of the ionic liquids, their toxicity and their added value to a process, for example, are critical. We would like to thank all the authors for their hard work in reviewing the subject matter for this book and for providing their insight into the future.

Christopher Hardacre and Vasile I. Parvulescu