| It has been observed that nonlinear systems in far from equilibrium states exhibit the formation of patterns such as spirals, target patterns, etc. One such system is the heterogeneous catalytic reaction of CO oxidation on Platinum. In this study we investigate the effects of spatial thermal gradients on spirals during CO oxidation on single crystal platinum (110) for the first time. Our simulation results indicate that spirals tend to move towards regions with lower excitability under the effect of a thermal gradient. This translates to movement towards higher temperature regions for CO spirals and lower temperature regions for oxygen spirals. When conducting experiments, surface defects and subsurface oxygen patches can limit the mobility of the spirals. This makes finding a freely rotating spiral difficult, but despite these and other experimental difficulties, spirals moving toward lower excitability regions were observed experimentally. |
