Open Circuit Interaction of Formic Acid with Oxidized Pt Surfaces: Experiments, Modeling, and Simulations

We report in this work the study of the interaction between formic acid and an oxidized platinum surface under open circuit conditions. The investigation was carried out with the aid of in situ infrared spectroscopy, and results analyzed in terms of a mathematical model and numerical simulations. It has been found that during the first seconds of the interaction a small amount of CO(2) is produced and absolutely no adsorbed CO was observed. A sudden drop in potential then follows, which is accompanied by a steep increase first of CO(2) production and then by adsorbed CO. The steep transient was rationalized in terms of an autocatalytic production of free platinum sites which enhances the overall rate of reaction. Modeling and simulation showed nearly quantitative agreement with the experimental observations and provided further insight into some experimentally inaccessible variables such as surface free sites. Finally, based on the understanding provided from the combined experimental and theoretical approach, we discuss the general aspects influencing the open circuit transient.

Fundacao de Amparo a Pesquisa do Estado de So Paulo (FAPESP)[09/07629-6]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Cientifico (CNPq)[141723/2009-2]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Conselho Nacional de Desenvolvimento Cientifico (CNPq)[302698/2007-8]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)