Doped metal oxide electrocatalyst supports with enhanced conductivity

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Polymer electrolyte membrane fuel cells (PEMFC) are clean, portable power sources powered by hydrogen from secure and renewable sources that produce water and electricity. Current PEMFC technology relies heavily on platinum (Pt) electrocatalysts to drive the anodic and cathodic reactions. Normally, Pt nanoparticles are dispersed onto a high surface carbon support (Pt/C) to maximize the surface area of the catalyst and increase cell performance. While carbon black has been the de facto catalyst support in fuel cell over the last 30 years, it is a liability when it comes to durability since it is prone to corrosion under the highly acidic and oxidative operating conditions of a PEM fuel cell. This is detrimental to the long-term performance of a fuel cell and hinders the longevity of fuel cell devices. Thus, new materials are needed to address these fundamental issues. My lab recently discovered an exciting and entirely new fuel cell catalyst support material. Specifically, his group has invented a conductive metal oxide catalyst support that has the potential to replace the carbon support commonly used in current fuel cell electrodes. This proposal is focused on the study and enhancement of a new reaction whereby we dope low cost metal oxides like titanium dioxide with various metals and semi-metals (e.g. Mo, Si). My lab was the first to discover that doping with silicon (Si) could greatly enhance the conductivity of these metal oxide support materials. These new support materials have extremely high stability to corrosion and remarkable high electronic conductivity, considerably larger than any other metal oxide-based support developed to date. These properties make these supports highly attractive for deployment in fuel cell systems for automotive and stationary power applications. A more stable support that also enhances the performance/stability of the expensive Pt catalyst would revolutionize fuel cells, improving performance and operational lifetimes, thereby enabling greater uptake of fuel cell technology to replace less eco-friendly power sources used in automotive and stationary power applications. Our long-term objectives seek to understand how the presence of the doping elements (e.g Si, Mo) influences the physical properties of the resultant oxide material. Furthermore, I seek to understand how doping influences the electrochemical properties of the support and nanoparticle catalyst particles that are dispersed onto it. To address these questions, my group will create novel metal oxide support materials with different compositions and perform detailed electrochemical studies of these supports and catalysts. Furthermore, the durability of these catalysts will be examined in order to understand how chemical composition and operating conditions influence the stability of these electrode materials so that they can be better used in reliable clean energy technology.