Electro-oxidation of mixed fuels: kinetical instabilities and mechanism

• Grant number: 12/07313-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2012
• End date: December 31, 2016
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Hamilton Brandão Varela de Albuquerque
• Grantee: Eduardo Giangrossi Machado
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 09/07629-6 - Electrocatalysis IV: fundamental and applied aspects of electrocatalytic processes, bio-electrocatalysis and kinetic instabilities, AP.BIOEN.TEM
• Associated scholarship(s): 15/19839-6 - Electro-oxidation of mixed fuels: kinetics and dynamic instabilities, BE.EP.DR

Abstract

Low temperature fuel cells with proton exchange membrane are usually fueled with oxygen or air on the cathode and, e.g. hydrogen or small organic molecules on the anode. Aiming at combining some properties of different anodic fuels synergistically, it was recently proposed the mix of fuels, e.g. hidrazin/formic acid. Despite the fact that not much attention was given to the matter, there are some evidence that some kinetical instabilities may be present during the electro-oxidation of these mixtures. In that way, exploring the details of these instabilities can be an interesting strategy to obtain mechanistic information for these systems. The objective of this project is to study systematically these phenomena, paying special attention to far from thermodynamic state experiments and to a parameter range in which current/potential oscillations occur. For that, two different mixtures will be used: hidrazin/formic acid and ethanol/borohydride. The study will be made by electrochemical techniques, e.g. cyclic voltammetry and steady-state conditions, moreover with spectroscopic and gravimetric techniques, such as Differential Electrochemical Mass Spectroscopy (DEMS) and Electrochemical Quartz Crystal Nanobalance (EQCN). The results of these studies can provide relevant information regarding how these fuels interact with each other, and even can reveal a condition in which the performance of fuel cells can be increased.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ZIMER, ALEXSANDRO MENDES; DA SILVA, MARINA MEDINA; MACHADO, EDUARDO G.; VARELA, HAMILTON; MASCARO, LUCIA HELENA; PEREIRA, ERNESTO CHAVES. Development of a versatile rotating ring-disc electrode for in situ pH measurements. Analytica Chimica Acta, v. 897, p. 17-23, OCT 15 2015. (13/16930-7, 13/13503-0, 12/07313-1, 11/19430-0, 13/07296-2)

PREVIDELLO, BRUNO A. F.; MACHADO, EDUARDO G.; VARELA, HAMILTON. The effect of the alkali metal cation on the electrocatalytic oxidation of formate on platinum. RSC ADVANCES, v. 4, n. 29, p. 15271-15275, 2014. (12/24152-1, 12/21204-0, 09/07629-6, 12/07313-1)

MACHADO, EDUARDO G.; DELMONDE, MARCELO V. F.; VARELA, HAMILTON. Spectrometric Evidence of the Synergy between Formic Acid and Hydrazine on Their Electro-Oxidation. Journal of the Electrochemical Society, v. 164, n. 9, p. H647-H650, 2017. (12/24152-1, 13/16930-7, 12/07313-1)

MACHADO, EDUARDO G.; VARELA, HAMILTON. Complex Dynamics in the Electro-Oxidation of Formic Acid Assisted by Hydrazine in Acidic Media. Journal of the Electrochemical Society, v. 163, n. 3, p. H186-H191, 2016. (12/24152-1, 13/16930-7, 12/07313-1)

MACHADO, EDUARDO G.; VARELA, HAMILTON. Oscillatory instabilities in the electrooxidation of borohydride on platinum. Journal of the Brazilian Chemical Society, v. 25, n. 3, p. 442-447, MAR 2014. (12/24152-1, 09/07629-6, 12/07313-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MACHADO, Eduardo Giangrossi. Formic acid electro-oxidation assisted by hydrazine. 2017. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) São Carlos.