Title of article :
Stochastic aspects of pattern formation during the catalytic oxidation of CO on Pd(111) surfaces
Author/Authors :
Wehner، نويسنده , , Stefan and Karpitschka، نويسنده , , Stefan and Burkov، نويسنده , , Yevgen and Schmeisser، نويسنده , , Dieter and Küppers، نويسنده , , Jürgen and Brand، نويسنده , , Helmut R.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Pages :
6
From page :
746
To page :
751
Abstract :
We present experimental results on rare transitions between two states due to intrinsic noise between two states in a bistable surface reaction, namely the catalytic oxidation of CO on Pd(111) surfaces. The mean time scales involved are typically of order 104 s and the probability distribution shows two peaks over a large part of the bistable regime of this surface reaction. We use measurements of the resulting CO2 rate as well as photoelectron emission microscopy (PEEM) to characterize these rare transitions. From our dynamic data we can extract probability distributions for the CO2 rate. We use x – t plots from PEEM measurements to describe the transitions, which are–as we demonstrate–characterized by one wall moving through the field of view in PEEM measurements. The resulting probability distributions for the CO2 rate are shown to depend strongly on the value, Y, of the CO fraction in the reactant flux inside the bistable regime. We find that the probability distribution is strongly asymmetric indicating that the two basins of attraction are rather different in depth and width. This is also concluded from the PEEM measurements, which show in one case a rather sharp and narrow domain wall going one way, while it is rather wide and diffuse for the motion in the opposite direction. To have two basins of attraction in the bistable regime, which are rather different in nature is reminiscent of other bistable systems such as, for example, optical bistability, although the time scales involved in the present system are entirely different.
Keywords :
chemical reactions , surface reactions , Bistability , Nonlinear dynamics
Journal title :
Physica D Nonlinear Phenomena
Serial Year :
2010
Journal title :
Physica D Nonlinear Phenomena
Record number :
1729392
Link To Document :
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