Alkali Cation Effect During the Oscillatory Electroreduction of H2O2 on Pt. Issue 35 (19th December 2017)

• Record Type: Journal Article
• Authors: da Silva, Kaline N.; Nagao, Raphael; Sitta, Elton
• Is Part Of: ChemistrySelect. Volume 2:Issue 35(2017)
• Page Start: 11713
• Page End: 11716
• Publication Date: 2017-12-19
• Subjects: Cation Effect -- Competition on Surface -- H2O2 Electroreduction -- N- NDR oscillator -- Oscillations; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201702276
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Hydrogen Peroxide Reduction Reaction (HPRR) catalyzed by Pt was studied in alkaline media and the effect of alkali cations were analyzed by the changes on dynamic instabilities presented by this system under high ohmic drop conditions. The origin of these instabilities is the competition between OH2 − electroreduction and hydrogen adsorption on Pt surfaces, the latter being the first step for hydrogen evolution reaction (HER). Both HER and hydrogen adsorption are cation‐dependent which suggests that noncovalent interactions are able to stabilize the water molecules favoring the Pt−H formation. Thus, in an interphase, in which the noncovalent interactions are more effective, HPRR will proceed as an indirect poisoned system, reflecting on slow frequency oscillations ( ω ), for instance ω LiOH < ω NaOH < ω KOH for several H2 O2 concentrations. Abstract : Alkali cations indirectly affect the oscillatory H2 O2 electroreduction reaction by the stabilization of water molecules on interface: In the presence of Li +, Had formation is slightly favoured, decreasing the frequency of oscillations by 25‐fold when compared with K + .