Carbon-titanium oxide electrocatalyst supports for oxygen reduction in PEM fuel cells

Abstract

A high surface area support material is formed of an intimate mixture of carbon clusters and titanium oxide clusters. A catalytic metal, such as platinum, is deposited on the support particles and the catalyzed material us as an electrocatalyst in an electrochemical cell such as a PEM fuel cell. The composite material is prepared by thermal decomposition and oxidation of an intimate mixture of a precursor carbon polymer, a titanium alkoxide and a surfactant that serves as a molecular template for the mixed precursors.

Description

[0001]This application claims priority based on provisional application 60 / 938,864, titled “Carbon-Titanium Oxide Electrocatalyst Supports for Oxygen Reduction in PEM Fuel Cells,” filed May 18, 2007 and which is incorporated herein by reference.TECHNICAL FIELD[0002]This invention pertains to catalyst support materials for use in electrodes of polymer electrolyte membrane (PEM) fuel cells. More specifically, this invention relates to the preparation and use of such catalyst support materials that are a composite of carbon and titanium oxide.BACKGROUND OF THE INVENTION[0003]PEM fuel cells use electrocatalysts for the oxidation of hydrogen at the anode and reduction of oxygen (in air) at the cathode. Currently, platinum (Pt) and its alloys supported on high surface area carbons are the only feasible electrocatalyst for proton exchange membrane (PEM) fuel cell systems. However, a significant problem hindering large-scale implementation of PEM fuel cell technology is the loss of performa...

AI Technical Summary

Benefits of technology

The invention is about a new material that can be used as a support for catalysts in fuel cells. The material is made by combining titanium dioxide and carbon in a controlled way. The resulting material has good electronic conductivity, chemical stability, and a high surface area. Platinum can also be deposited on the material and tested in a fuel cell. The method for making the material involves using a surfactant to mix precursors, heating them, and removing impurities. The resulting material has a unique structure with titanium dioxide and carbon atoms mixed at a molecular level. Overall, this material can improve the performance of fuel cells by providing a better support for catalysts.

Problems solved by technology

However, a significant problem hindering large-scale implementation of PEM fuel cell technology is the loss of performance during automotive vehicle cycling and extended operation.

Recent investigations of the deterioration of cell performance have revealed that a considerable part of the performance loss is due to the degradation of the electrocatalyst.

Although carbon has been considered as a most suitable catalyst support owning to its low cost, good electron conductivity, high surface area, morphology allowing gas diffusion, and chemical stability; corrosion of carbon supports on the cathode side of PEM fuel cells is emerging as a challenging issue for long-term stability of PEM fuel cells.

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