ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The rate of catalytic carbon monoxide oxidation on a Pt(100) single crystal surface under isothermal, low-pressure conditions exhibits for certain ranges of parameters (O2 and CO partial pressures, temperature) sustained temporal oscillations whose mechanism had been explored in previous work. Coupling between reaction and diffusion leads to spatial pattern formation as manifested by patches with different work function on the intrinsically homogeneous surface. Imaging is performed by means of the novel technique of scanning photoemission microscopy. Typically, nuclei with dimensions of a few microns, as determined by the instrumental resolution, are formed spontaneously and expand with sharp fronts and velocities of about 0.5 mm/min (at 480 K) up to sizes ≥1 mm. Waves with even more extended fronts propagating with somewhat higher velocities across the sample surface are responsible for the occurrence of large amplitude temporal oscillations of the integral reaction rate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.456735
