This thesis describes the preparation and study of a wide range of supported gold catalysts based on atomically-precise triphenyl phosphine stabilised gold clusters. This selected range of ligand-stabilised gold clusters were prepared in attempt to study the effect of increasing cluster nuclearity on the electronic and catalytic properties of these materials. A novel far-infrared study was conducted on the pure cluster materials in attempt to understand the metal-metal and the metal–ligand vibrations, which was also compared to the simulated spectra for each cluster. The design and activation of these novel catalysts based on gold clusters was discussed and the factors that influence activity were described. A comprehensive photoelectron study of the catalysts was conducted in an attempt to understand the electronic structure of the supported gold clusters and the effect of various activation conditions have on the electronic structure of the gold clusters. A selection of the prepared supported gold catalysts were tested for their catalytic activity for the partial oxidation of styrene and the influence of the several activation conditions on the reactivity of the catalyst is also examined. In collaboration, the application of a selection of ligand-stabilised gold clusters as hydrogen sensors and as catalysts for the photocatalytic generation of hydrogen from ethanol is also investigated.