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Información tecnológica

versión On-line ISSN 0718-0764

Resumen

SUSTERSIC, G.M.; MORENO, D.  y  VON MENGERSHAUSEN, A.E.. Underpotential Deposition of Hydrogen on Polycrystalline Gold. Inf. tecnol. [online]. 2004, vol.15, n.4, pp. 85-90. ISSN 0718-0764.  http://dx.doi.org/10.4067/S0718-07642004000400012.

The purpose of this work is to demonstrate the presence of underpotential hydrogen adsorbed (H UPD) on gold. The application of a triangular potential disturbance leads to the appearance of cathodic/anodic current peaks that represent electrochemical hydrogen adsorption/desorption at less negative potentials than those producing the hydrogen evolution reaction. The different current peaks correspond to the adsorption of hydrogen on different crystalline planes. The presence of adsorbed atomic hydrogen is chemically demonstrated by reduction of silver ion. The results suggest that the hydrogen diffuses inside the metal and adsorbs when the inward and outward diffusion velocities become equivalent. The surface crystalline imperfections, which are consequence of the cold working deformations not totally eliminated by the thermal treatment, favor diffusion in both directions. A role for the H UPD as mediator in organic reduction reactions is proposed

Palabras clave : underpotential deposition; hydrogen adsorption; polycrystalline gold; adsorption.

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