Colored noise-enhanced intrinsic stochastic oscillations in CO oxidation on nanometer-sized Pd particles

Abstract

How colored Gaussian noise (CN) affects the intrinsic stochastic oscillations (ISO) of CO oxidation on a nm-sized Pd particle is studied. It is found that the optimal ISO can be enhanced not only by a CN with appropriate noise intensity, but by a CN with appropriate correlation times. Moreover, the optimal ISO can be most greatly enhanced by the CN when the noise intensity or the correlation time is optimal. This result shows that external noise may, via its interplay with the internal noise of the system, play a constructive role in the ISO of the system, and the ISO can employ the external noise to reach a best oscillation performance.

Non-Gaussian noise-enhanced stochastic rate oscillations in CO oxidation on nanometer-sized Pd particles

“…This phenomenon demonstrates that the optimal ISRO in the absence of external noise can still be enhanced by appropriate NGN, and the enhancement is greater than that by the colored Gaussian noise (q = 1), which is also indicated in the result in ref. [20]. In addition, the ISRO for the NGN with q = 1.1 is a little more regular than the optimal ISRO for the white Gaussian noise [19].…”

“…To overcome this problem, Gillespie [44] developed a chemical Langevin equation (CLE) and stated that the CLE is a rather good approximation of the exact master equation if a 'macroscopically infinitesimal time scale' exists in the dynamics. The CLE has been successfully used to study the effect of internal noise in not too small chemical and biological systems [14,15,[18][19][20][21][22]. For the present system, there are hundreds to thousands of reactant molecules (absorption centers) on the particle surface [11], thus the CLE is valid for the present study.…”

“…In a circadian oscillator driven by external and internal noise, the external noise CR can be suppressed by the internal noise, while the internal noise coherence resonance (INCR) can be enhanced by the modulation of the external noise strength in a certain range of noise intensity [18]. In CO oxidation on nanometer-sized Pd particles, the INCR can be enhanced by the external noise [19,20]. In NO reduction by CO on small-size Pt surfaces, the internal noise can enhance the external noise CR, and the external noise either enhances [21,22] or suppresses [23] the INCR, depending on its sources.…”