Since Haruta et al. discovered that small gold nanoparticles finely dispersed on certain metal oxide supports
can exhibit surprisingly high activity in CO oxidation below room temperature, heterogeneous catalysis by
supported gold nanoparticles has attracted tremendous attention. The majority of publications deal with the
preparation and characterization of conventional gold catalysts (e.g., Au/TiO2), the use of gold catalysts in
various catalytic reactions, as well as elucidation of the nature of the active sites and reaction mechanisms. In
this overview, we highlight the development of novel supported gold catalysts from a materials perspective.
Examples, mostly from those reported by our group, are given concerning the development of simple gold
catalysts with single metal-support interfaces and heterostructured gold catalysts with complicated interfacial
structures. Catalysts in the first category include active Au/SiO2 and Au/metal phosphate catalysts, and those in
the second category include catalysts prepared by pre-modification of supports before loading gold, by
post-modification of supported gold catalysts, or by simultaneous dispersion of gold and an inorganic
component onto a support. CO oxidation has generally been employed as a probe reaction to screen the activities
of these catalysts. These novel gold catalysts not only provide possibilities for applied catalysis, but also furnish
grounds for fundamental research.