Simple surface reactions like the CO-oxidation on single crystal Pt surfaces show a rich variety of pattern formation under specific reaction parameters. To visualize those patterns we have conceived several unique imaging methods starting around 1990. The interaction of a multitude of micrometer scale concentration waves and fronts on the surface complicate our understanding the underlying mechanisms for such patterns. Experiments with modified catalytic activity using stationary, inactive boundaries have therefore been designed to isolate individual features (for example single pulses) and interaction mechanisms in order to study them quantitatively. Since 2001 we have been able to dynamically change the surface catalytic activity in real time and space by focusing an addressable laser beam to differentially heat a Pt(110) single crystal surface. The combination between the fixed microstructures of metals with different catalytic activities and local laser heating of the surface has been recently explored.