Non-Equilibrium Thermodynamics and Stochastic Dynamics of a Bistable Catalytic Surface Reaction

Abstract

Catalytic surface reaction networks exhibit nonlinear dissipative phenomena, such as bistability. Macroscopic rate law descriptions predict that the reaction system resides on one of the two steady-state branches of the bistable region for an indefinite period of time. However, the smaller the catalytic surface, the greater the influence of coverage fluctuations, given that their amplitude normally scales as the square root of the system size. Thus, one can observe fluctuation-induced transitions between the steady-states. In this work, a model for the bistable catalytic CO oxidation on small surfaces is studied. After a brief introduction of the average stochastic modelling framework and its corresponding deterministic limit, we discuss the non-equilibrium conditions necessary for bistability. The entropy production rate, an important thermodynamic quantity measuring dissipation in a system, is compared across the two approaches. We conclude that, in our catalytic model, the most favorable non-equilibrium steady state is not necessary the state with the maximum or minimum entropy production rate.

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“…The crossing point clearly discerns continuous and discontinuous phase transitions and can be used as an indicator of the phase coexistence, as observed in Ref. [135] (Figs. 7 and 8) for a chemical reaction model.…”

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“…O ponto de cruzamento distingue claramente as transições de fase contínuas das descontínuas e pode ser usado como um indicador da coexistência de fases, como se mostra no próximo capítulo nas figuras (5.5) e (5.8), também na Ref. [40] (Figs. 7 e 8) para um modelo de reação química.…”