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 s cheme, and a modified part (SM), on which the reaction proceeds in acc ordance with a five-stage scheme with the participation of two forms o f adsorbed oxygen. In this model, consideration is also given to the f ormation of surface beta-oxygen on the SM surface [initialty on defect s of the Pt(110)] and to its reaction with CO, and also to diffusion p f Co(ads) between the SN and SM surfaces. The ratio of the sections SN /SM is determined by the concentration of beta-oxygen. Calculations ar e performed to describe the dynamics of development of autooscillation s: an initial induction period, generation of oscillations and an incr ease of their period, and appearance of oscillations with a very long period (tens of minutes) and ''packets'' of pulses.