Study of electronic properties effect of platinum and rhodium binary electrocatalysts for ethanol oxidation

• Grant number: 05/00081-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2006
• End date: January 31, 2007
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Edson Antonio Ticianelli
• Grantee: Alexei Lorenzetti Novaes Pinheiro
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The development of fuel cells to substitute the oil based energy sources is a subject of utmost strategic importance worldwide with a strong environmental appeal. In the particular case of Brazil, the development of highly efficient ethanol based fuel cell systems would be highly attractive, since the country possess the technology for ethanol production from renewable sources and a distribution system already installed. This project includes the study of the electrocatalytic activity of bimetallic platinum-rhodium model systems that imitate anode catalysts for ethanol electrochemical oxidation in fuel cells. This study comprises the preparation and characterization, in ultra-high-vacuum conditions, of pseudomorphic rhodium films on low Miller index platinum surfaces and platinum films on single crystal rhodium as well. UHV techniques will be used both in the surface preparation of well-controlled surfaces and analytical characterization. The position of the metallic system d-band center will be measured by ultraviolet photoelectron spectroscopy, since this property has been ascribed as a key factor to the binding energy of adsorbed species and consequently to the electrocatalytic activity. The performance of these model-systems to the electrochemical ethanol oxidation will be evaluated by Differential Electrochemical Mass Spectrometry (DEMS) due to the complexity of the reaction mechanism. At the end we hope to be able to better understand, from a fundamental approach, the dominant mechanisms involved in the catalytic activity in connection with real systems of technological interest. (AU)