Enhancement of Stochastic Resonance Induced by Either Internal or External Noise in NO Reduction on Platinum Surfaces

Abstract

Using the chemical Langevin equation (CLE), we have studied the effects of the interaction between internal and external noise on the oscillatory kinetics in the mesoscopic stochastic system of NO reduction by CO on single-crystal platinum surfaces. It is found that, when the system is driven by internal and external noise simultaneously, external noise and internal noise can enhance the stochastic resonance induced by internal noise (SRIN) and by external noise (SREN), respectively. Moreover, there exists an optimal external noise strength for the enhancement of SRIN and an optimal system size for the enhancement of the stochastic resonance by external noise (SREN), respectively. This result shows that internal and external noise would benefit the stochastic reaction oscillations induced by each other, and play similar positive roles in enhancing SREN and SRIN, respectively, though they are generated in different mechanisms. In addition, the enhancements of SRIN and SREN are selective to external and internal noise intensity, respectively. It is also shown that the optimal system size for the SRIN and the optimal external noise intensity for the SREN can be regulated by external noise and internal noise, respectively.