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| Texas NanoEnergy Collaborative |
Principal Investigator
Peter Strasser [ Bio]
Assistant Professor, Department of Chemical Engineering
The University of Houston
Project Period: 06/01/2007 - 08/31/2008
Regenerative Polymer Electrolyte Membrane Fuel Cells (RFC) are designed to combine the function of an electrochemical energy conversion devices (fuel cell mode) with that of an electrochemical energy storage device (electrolyzer mode). During fuel cell mode operation, stored hydrogen fuel is converted into electricity, while operation in the storage mode converts externally supplied electricity into hydrogen fuel. These power devices offer attractive specific powder density characteristics where weight is a major concern.
Both operation modes can be realized either using one single Membrane Electrode Assembly (MEA) (unified design) or using two individual MEAs in series where one acts as electrolyzer and the other as fuel cell (discrete design).
Currently, the performance of RFCs is limited by the catalytic activity of the oxygen reduction process (fuel cell mode at cathode) and of the oxygen gas evolution process (storage mode at the anode). Both reactions exhibit sever electrochemical overpotentials which lower their energy efficiencies. Furthermore, the corrosive conditions of the oxygen electrodes damage the electrocatalysts and result in performance losses over time.
This project aims at the development of nanoparticle Pt alloy electrocatalyst with improved oxygen gas evolution and oxygen reduction kinetics. Alloying Pt with other transition metals modifies their surface geometric and electronic structure and results in a change of their surface catalytic activity compared to pure Pt catalysts. Pt alloys involving highly corrosive metals such as Ru, Ir, or Rh will be tested for their oxygen evolution kinetics, while Pt alloys with first row transition metals such as Cr, Ti, Ni will be tested for their oxygen reduction activity.
All promising nanoparticle catalysts for the oxygen half cell will be tested for both reduction and evolution in order to identify suitable candidates for unified RFCs.
In order to cover the full range of stoichiometries in the compositional parameter space, automated synthesis methods and high throughput electrocatalytic testing methodologies will be used during this project. Interesting candidates will be scaled-up and their structure- performance relationships will be investigated in more detail using single Rotating Disk Electrode measurements.
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| Page Updated/Reviewed: 03/24/2008 11:17 AM |
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