Preparation of Pt and Ru binary electrocatalysts for methanol oxidation

• Grant number: 05/00853-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2005
• End date: July 31, 2006
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Teresa Benita Iwasita de Vielstich
• Grantee: Monise Cristina Ribeiro Casanova
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The purpose of this project is the preparation of platinum ruthenium bimetallic catalysts by chloroplatinic acid reduction by dissolved hydrogen under sonication of a high surface area carbon suspension. Preliminary studies show that by sonicating the suspension it is possible to obtain platinum and ruthenium solid mixtures at any atomic concentration, in contrast with chloroplatinic reduction by formic acid. In this project we will determine the conditions to control the size of the particle through the dilution of the platinum salt and of the ultrasound power for the different atomic platinum-ruthenium compositions of the supported catalysts. The synthesized catalysts will be analyzed by X-ray diffraction and high-resolution transmission electron microscopy to evaluate the size of the particles and by dispersive X-ray analysis to determine the mean composition of the particles (and possibly the composition distribution of nanoparticles ensembles). The obtained electrocatalysts will be used for the methanol electrochemical oxidation and the activity will be determined by cyclic voltammetry and chronoamperometry and the CO2 yield by on line mass spectrometry (DEMS).