Investigation of the catalytic activity of nanostructured electrocatalysts for BH4- ions electrooxidation in alkaline media

• Grant number: 11/03672-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2011
• End date: February 28, 2013
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fabio Henrique Barros de Lima
• Grantee: Aniélli Martini Pasqualeti
• 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): 12/00877-7 - Investigation of the nanostructured electrocatalysts composed by Ag and Pd for BH4- ions electrooxidation in alkaline media, BE.EP.MS

Abstract

The direct borohydride fuel cells exhibit a high theoretical voltage (1,64 V) and high number of electrons per borohydride ion. In addition, the use of alkaline electrolytes opens the possibility of using non-noble metal electrocatalysts and, therefore, it is economically viable for practical application. However, the lack of a highly efficient electrocatalyst for the borohydride oxidation reaction limits the performance of these devices. The most commonly studied electrocatalysts for this reaction are composed by gold and platinum. However, in these metals, the total oxidation reaction, involving 8 electrons per BH4- species, competes with parallel reactions with lower number of exchanged electrons. In view of this, and just recently, simulations and theoretical calculations were performed to determine the elementary steps of reaction kinetics and also to guide the rational preparation of metal electrocatalysts for the borohydride oxidation. Considering the above mentioned issues, and based on the results of theoretical studies, this research project aims at advancing in the knowledge of the mechanism, and at the development of more active electrocatalysts for the borohydride oxidation reaction. The electrocatalysts will be composed by the combination of metals with different adsorption energies for the borohydride ions, such as AuCu and PdAg, as indicated by theoretical studies. All electrocatalysts will be nanostructured and supported on carbon powder of high surface area. The electrocatalytic activities will be studied by steady state polarization curves using rotating disc electrodes. The borohydride hydrolysis, with the production of H2, will be monitored in function of the electrode potential by on line differential electrochemical mass spectrometry, using a dual thin layer flow cell. In situ Infrared spectroscopy experiments will be conducted to monitor the different species that produced and are consumed during the course of the reaction for the different investigated electrocatalysts. (AU)

Scientific publications

(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)

PASQUALETI, ANIELLI M.; OLU, PIERRE-YVES; CHATENET, MARIAN; LIMA, FABIO H. B.. Borohydride Electrooxidation on Carbon-Supported Noble Metal Nanoparticles: Insights into Hydrogen and Hydroxyborane Formation. ACS CATALYSIS, v. 5, n. 5, p. 2778-2787, MAY 2015. (11/03672-4, 11/50727-9, 13/16930-7, 12/00877-7)

LIMA, FABIO H. B.; PASQUALETI, ANIELLI M.; CONCHA, M. BELEN MOLINA; CHATENET, MARIAN; TICIANELLI, EDSON A.. Borohydride electrooxidation on Au and Pt electrodes. Electrochimica Acta, v. 84, n. SI, p. 202-212, DEC 1 2012. (11/03672-4, 09/07629-6)

LIMA, FABIO H. B.; PASQUALETI, ANIELLI M.; CONCHA, M. BELEN MOLINA; CHATENET, MARIAN; TICIANELLI, EDSON A.. Borohydride electrooxidation on Au and Pt electrodes. Electrochimica Acta, v. 84, p. 11-pg., 2012-12-01. (09/07629-6, 11/03672-4)

Academic Publications

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

PASQUALETI, Aniélli Martini. Investigation of the catalytic activity of nanostructured electrocatalysts for BH4- ions electro-oxidation in alkaline media. 2013. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) São Carlos.