Abstract

MACHADO, E  and  BUENDIA, G. M. Response of a model for catalytic oxidation of CO to periodic variation of the reactant's pressure. Rev. mex. fis. [online]. 2006, vol.52, suppl.3, pp.42-44. ISSN 0035-001X.

We study the response of the Ziff-Gulari-Barshad model with CO desorption (ZGB-k) to a periodic variation of the external CO pressure around the discontinuous and asymmetrical transition between the reactive regime (with CO2 production) and the inactive regime (with the surface poisoned by CO). In one period the CO pressure, y, takes the values y_l and y_h during the time intervals t_d and t_p, respectively. We find that, depending on the values of t_d and t_p, there is a significative enhancement in the catalytic activity of the system compared with its stationary values. In particular we find that the maximum value of CO2 production does not occurs when t_d = t_p as it is commonly assumed, this is due to the asymmetry of the decay times of the metastases phases of the model.

Keywords : Nonequilibrium thermodynamics; heterogeneous catalysis at surfaces; ZGB modelo.