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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spectrometric Evidence of the Synergy between Formic Acid and Hydrazine on Their Electro-Oxidation

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Machado, Eduardo G. [1] ; Delmonde, Marcelo V. F. [1] ; Varela, Hamilton [1]
Total Authors: 3
[1] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of the Electrochemical Society; v. 164, n. 9, p. H647-H650, 2017.
Web of Science Citations: 1

The electro-oxidation of formic acid on platinum electrodes has been on the spotlight for the last decade since it presents an apparent simple, yet intricate mechanism with three known reaction pathways. Despite the formation of CO, a strongly adsorbed intermediate, it was reported an interesting behavior when hydrazine is added in this solution. The simultaneous oxidation of formic acid and hydrazine was argued to be additive, meaning that both molecules would be oxidized without one interfering to the other. However, recently, it was suggested that this process would proceed synergistically. In this work, we aim at understanding how both molecules are oxidized on a platinum surface by monitoring the formation of gaseous products with Differential Electrochemical Mass Spectrometry (DEMS). The chosen pH was acidic (similar to 0.3) and the working electrode employed was a platinum sputtered Teflon membrane. The results showed that the signal of the ratio mass/charge 44 (related to CO2 production) for the formic acid and hydrazine system exhibited a new peak at lower potentials (c. a. 0.55 V), where the oxidation of formic acid would not proceed in the absence of hydrazine. The enhanced production of CO2 in the presence of hydrazine, which does not contain any carbon on its structure, yields the spectrometric proof that a more-than-additive mechanism takes place when oxidizing the mixture. These results open a new perspective for the study of the mechanism of the formic acid oxidation and to the development of new mixed fuels for energy conversion devices. (C) 2017 The Electrochemical Society. All rights reserved. (AU)

FAPESP's process: 12/24152-1 - Complex kinetics in electrochemical systems: mechanisms, stoichiometric network analysis and numerical simulations
Grantee:Hamilton Brandão Varela de Albuquerque
Support type: Scholarships abroad - Research
FAPESP's process: 12/07313-1 - Electro-oxidation of mixed fuels: kinetical instabilities and mechanism
Grantee:Eduardo Giangrossi Machado
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
Grantee:Edson Antonio Ticianelli
Support type: Research Projects - Thematic Grants