ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
2 files

Standard Underpotential Deposition Shift. A New Parameter to Characterize the UPD Phenomenon.

preprint
submitted on 04.03.2021, 19:05 and posted on 05.03.2021, 12:58 by Rafael Alcides Vicente, Heloísa Vampré Nascimento Gomes, Pablo Fernández

Underpotential deposition (UPD) is a phenomenon where atoms of an element M are deposited from ions Mn+ on a substrate S at potentials more positive than for the deposition of Mn+ on M. These systems have been studied for more than a century and are interesting from both the applied and the fundamental point of view. Despite the vast literature on the subject, there is no thermodynamic parameter so far able to characterize an UPD system. Even if the so-called “UPD shift” has been used for decades, the limitations of this parameter has been fully recognized in the field. Herein, using a simple Nernstian treatment and straightforward measurements, we show how to measure and calculate a new proposed fundamental thermodynamic parameter namely, the “Standard UPD potential”. We showed results for the deposition of Cu+2 on Au in acidic media, in solutions containing ClO4- or SO4-2 anions. We obtained Standard UPD potential= 0.65 ± 0.02 V, independently of the concentration of the acid and the nature of the anion.

Funding

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (grants: 2017/11986-5, 2018/20952-0, 2019/07449-0, 2018/13262-7 and 2019/13888-6)

History

Email Address of Submitting Author

pablosf@unicamp.br

Institution

University of Campinas

Country

Brazil

ORCID For Submitting Author

0000-0002-5068-0556

Declaration of Conflict of Interest

I declare not conflict of interest

Exports

ChemRxiv

Exports