Resolving Catalytic Phenomena at the Atomic Scale Michael Bowker Cardiff University Abstract In this talk I will highlight the use of STM, especially carried out at high temperature, to investigate surface processes and I will relate these to phenomena observed in heterogeneous catalysis. Model nanoparticulate catalysts (metal nanoparticles on TiO2(110)) can be fabricated and imaged in situ in the STM, and the effects of conditions and gas treatment on the metal-oxide interaction will be reported. This covers such practically important phenomena as oxygen storage, spillover, strong metal-support interactions and sintering, all of considerable importance to automobile catalysts and therefore to the well-being of our environment.