MODELING THE DYNAMICS OF DEVELOPMENT OF REACTION-RATE AUTOOSCILLATIONS IN THE OXIDATION OF CARBON-MONOXIDE ON PLATINUM

The model examined in this article assumes that the Pt(110) surface in the process of CO oxidation consists of two parts: an original part (SN), on which the reaction proceeds in accordance with a three-stage scheme, and a modified part (SM), on which the reaction proceeds in accordance with a five-stage scheme with the participation of two forms of adsorbed oxygen. In this model, consideration is also given to the formation of surface beta-oxygen on the SM surface [initialty on defects of the Pt(110)] and to its reaction with CO, and also to diffusion pf Co(ads) between the SN and SM surfaces. The ratio of the sections SN/SM is determined by the concentration of beta-oxygen. Calculations are performed to describe the dynamics of development of autooscillations: an initial induction period, generation of oscillations and an increase of their period, and appearance of oscillations with a very long period (tens of minutes) and ''packets'' of pulses.