The spontaneous formation of self-organized spatiotemporal patterns under far from thermodynamic equilibrium regime is a characteristic behavior in reaction-transport systems. Targets, waves, spirals, spots and stripes are some typical examples of these chemical self-organized patterns. The emergency of these structures are described by the coupling between the local chemical kinetics, which usually shows oscillatory time-series, and the exchange of spatial information by mass transport. In this work, two fronts will be presented using the nonlinear chemical dynamics in the elucidation of reaction mechanisms under far from thermodynamic equilibrium regime: (a) the investigation of the chemical nature and effect of the drift in the transient time-series in electrochemical oscillators. The analysis of the temporal evolution of the bifurcation parameter was based on an empiric method of stabilization, being the slow accumulation of oxygenated species the main responsible for the drift; (b) the decoupling of the parallel electrochemical routes for CO2 production by a combination of experiments, modeling and numerical simulations during the oscillatory electro-oxidation of methanol on polycrystalline platinum. The effect of perchlorate and sulfate anions in the parallel reactions was investigated by the global production of CO2 and HCOOCH3. Remarkably, sulfate anions inhibited more strongly the catalytic activity from direct pathway in contrast to the small alteration in the indirect pathway. The main idea presented converges in the obtainment of chemical kinetic information which is not observed in conditions close to the thermodynamic equilibrium. This interpretation might be used as an alternative methodology in the study of electrocatalysis in complex chemical reactions.

Elucidation of reaction mechanisms far from thermodynamic equilibrium

248th National Meeting (2014)

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