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Fuel Cell Catalyst Materials

Our fuel cell catalyst work is done through the Cornell Fuel Cell Institute.

John Gregoire "Fabrication and testing instrumentation for high-throughput electrochemistry"

I am a graduate student in the physics department contributing to the research efforts of Professor vanDover and Frank DiSalvo, professor of chemistry. I received my B.A. in physics and mathematics from Concordia College, Moorhead, MN in 2004 and am currently right in the middle of my Cornell graduate school career.

My primary research focus is the development of fabrication and testing instrumentation for combinatorial, high throughput electrochemistry. In 2006, a new sputtering system came online, featuring a 4-gun ensemble (Angstrom ONYX-2 DC magentron) for deposition of composition spread thin films, a liquid nitrogen getter (cryoshroud), and an ensemble of 3 custom-made substrate heaters. Please feel free to contact me for details on the system, or please note the paper in the summer 2007 RSI special issue on combinatorial methods.

Commonly, films fabricated in this new system are evaluated as catalysts of reactions of interest to the fuel cell community. In 2007, a high-throughput electrochemistry testing station will be added to the lab which, in combination with the new deposition system, will allow for the fabrication and evaluation of more that 30 films per week. The electrochemical testing station is based on that described in M. Prochaska, J. Jin, D. Rochefort, L. Zhuang, F. J. DiSalvo, H. D. Abruna, R. B. van Dover, "High throughput screening of electrocatalysts for fuel cell applications" Review of Scientific Instruments 77, 054104 (2006).

With these instruments, we will exhaust the testing of ternary and 4-element pseudoternary composition spreads we feel may offer interesting catalytic properties.

Maxim Kostylev "Anode catalysts for PEMFCs "

It is fair to say that all major parts of a proton exchange membrane fuel cell (PEMFC) are, at present, far from ideal. Both hydrogen and direct alcohol fuel cells require new materials for anodes, cathodes, and membranes in order to have a chance to compete with the combustion engine and batteries. While in the Cornell Fuel Cell Institute (CFCI) we address simultaneously the major problems associated with all the three parts of PEMFCs, in the van Dover lab we are currently focusing on anode materials only. We employ a combinatorial approach that allows us to screen large parts of ternary phase space of any three elements and identify potential candidates for improved PEMFC anode materials.

More specifically: We use magnetron co-sputtering to prepare ternary composition thin films on standard Si wafers. We then carry out an electrochemical test on the whole composition spread, using methanol and ethanol as a fuel. The test allows us to identify any promising electrocatalytic regions, which we characterize for composition and structure. Once the region of interest is characterized, we pass the information to the nanoparticles synthesis group of CFCI, where our colleagues attempt to reproduce the potential anode catalyst in a more applicable nanoparticle form. Nanoparticles are then tested by yet another group in CFCI and are compared to the industrial standards that are presently available.

While the idea described above is relatively straightforward, questions related to the process continuously arise. One challenge, for example, is accurate characterization of the catalytically active region. The surface, which is responsible for catalysis, is almost always different from the bulk of the film due to oxide formation before and during the electrochemistry test as well as possible selective element leaching during the test. Presently I am working to determine an unexpected correlation between activity of certain compositions and thickness of the film. Properties of thin films should be independent of thicknesses above ~100 nm and should, therefore, result in similar electrochemical activity. Understanding the observed correlation may reveal important information about shortcomings in our methodology as well as provide insight about general film growth during co-sputtering of several elements.

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