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COMBINATORIAL SYNTHESIS AND REACTIVITY SCREENING OF ELECTRO-OXIDATION CATALYST GRADIENTS

Published online by Cambridge University Press:  01 February 2011

Shrisudersan Jayaraman  and
Andrew C. Hillier
Shrisudersan Jayaraman
Affiliation:
Department of Chemical Engineering, Department of Chemistry and Institute of Combinatorial Discovery Iowa State University, Ames, IA 50011
Andrew C. Hillier
Affiliation:
Department of Chemical Engineering, Department of Chemistry and Institute of Combinatorial Discovery Iowa State University, Ames, IA 50011
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Abstract

Combinatorial methods represent an appealing experimental method for the discovery of heterogeneous catalysts. One can efficiently identify candidate materials or sample vast regions of composition space using a combination of dense catalyst libraries and high-throughput reactivity screening techniques. This is particularly appealing for the discovery of novel catalysts for low temperature fuel cells where multi-component systems have shown improved performance. For example, the poison tolerance of typical anode catalysts can be improved by the addition of oxophilic components such as ruthenium, molybdenum, tin or osmium. Consequently, a vast composition space must be sampled in order to identify catalyst compositions or regions of composition space with greater activity. Combinatorial methods represent a practical means to speed-up the catalyst discovery process. In this manuscript, we demonstrate a novel method for combinatorial catalyst discovery based upon the synthesis and reactivity mapping of catalyst composition gradients. Samples consisting of uniform variations in surface composition of metals catalysts (Pt-M1 and Pt-M1−M2, where M1, M2 = Ru, Mo, Sn or Os) are fabricated using a gel-transfer technique. A concentration gradient of source metal ions is produced in a swollen polymer gel and then transferred onto a surface by electrodeposition to create a continuous composition gradient. An in situ reactivity-mapping tool based on the scanning electrochemical microscope is used to interrogate these catalyst gradients for the hydrogen oxidation reaction in the presence of adsorbed carbon monoxide.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 804: Symposium JJ – Combinatorial and Artificial Intelligence Methods in Materials Science II , 2003 , JJ8.11
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1. Rawlings, R. Tailoring properties - functionally graded materials. Materials World 3, 474–475 (1995).Google Scholar
2. Marple, B. R. & Boulanger, J., Graded casting of materials with continuous gradients. J. Amer. Cer. Soc. 77, 2747–2750 (1994).Google Scholar
3. Neubrand, A. & Rodel, J. Gradient materials: An overview of a novel concept. Z. Metal. 88, 358–371 (1997).Google Scholar
4. Ruardy, T. G., Schakenraad, J. M., vanderMei, H. C. & Busscher, H. J. Preparation and characterization of chemical gradient surfaces and their application for the study of cellular interaction phenomena. Surf. Sci. Rep. 29, 3–30 (1997).Google Scholar
5. Xiang, X.-D. et al. A combinatorial approach to materials discovery. Science 268, 1738–1740 (1995).Google Scholar
6. Reddington, E. et al. Combinatorial electrochemistry: a highly parallel, optical screening method for discovery of better electrocatalysts. Science 280, 1735–1737 (1998).Google Scholar
7. Ertl, G., Neumann, M. & Streit, K. M. Chemisorption of CO on the Pt(111) surface. Surf. Sci. 64, 393–410 (1977).Google Scholar
8. Appleby, A. J. & Foulkes, F. R. Fuel Cell Handbook (Van Nostrand Reinhold, New York, 1989).Google Scholar
9. Gasteiger, H. A., Markovic, N. M. & Ross, P. N. H2 and CO electrooxidation on well-characterized Pt, Ru, and Pt-Ru.1. Rotating-disk electrode studies of the pure gases including temperature effects. J. Phys. Chem. 99, 8290–8301 (1995).Google Scholar
10. Houghten, R. A. et al. Generation and use of synthetic peptide combinatorial libraries for basic research and drug discovery. Nature 354, 84–86 (1991).Google Scholar
11. Danielson, E. et al. A rare-earth phosphor containing one-dimensional chains identified through combinatorial methods. Science 279, 837–839 (1998).Google Scholar
12. Huo, Q., Sui, G., Kele, P. & Leblanc, R. M. Combinatorial surface chemistry- Is it possible? Angew. Chem. - Int. Ed. 39, 1854–1857 (2000).Google Scholar
13. Taylor, S. J. & Morken, J. P. Thermographic selection of effective catalysts from an encoded polymer-bound library. Science 280, 267–270 (1998).Google Scholar
14. Cong, P. J. et al. High-throughput synthesis and screening of combinatorial heterogeneous catalyst libraries. Angew. Chem. - Int. Ed. 38, 484–488 (1999).Google Scholar
15. Chaudhury, M. K. & Whitesides, G. M. How to make water run uphill. Science 256, 1539–1541 (1992).Google Scholar
16. Elwing, H. & Gölander, C. G. Protein and detergent interaction phenomena on solid-surfaces with gradients in chemical-composition. Adv. Coll. and Int. Sci. 32, 317–339 (1990).Google Scholar
17. Dertinger, S. K. W., Chiu, D. T., Jeon, N. L. & Whitesides, G. M. Generation of gradients having complex shapes using microfluidic networks. Anal. Chem. 73, 1240–1246 (2001).Google Scholar
18. Fuierer, R. R., Carroll, R. L., Feldheim, D. L. & Gorman, C. B. Patterning mesoscale gradient structures with self-assembled monolayers and scanning tunneling microscopy based replacement lithography. Adv. Mater. 14, 154-+ (2002).Google Scholar
19. Tingey, M. L., Luk, Y. Y. & Abbott, N. L. Orientations of liquid crystals on chemically functionalized surfaces that possess gradients in manometer-scale topography. Adv. Mater. 14, 1224-+ (2002).Google Scholar
20. Balss, K. M., Coleman, B. D., Lansford, C. H., Haasch, R. T. & Bohn, P. W. Active spatiotemporal control of electrochemical reactions by coupling to in-plane potential gradients. J. Phys. Chem. B 105, 8970–8978 (2001).Google Scholar
21. Jayaraman, S. & Hillier, A. C. Construction and reactivity mapping of a platinum catalyst gradient using the scanning electrochemical microscope. Langmuir 17, 7857–7864 (2001).Google Scholar
22. Lee, K. Y. C., Klingler, J. F. & McConnell, H. M. Electric-field-induced concentration gradients in lipid monolayers. Science 263, 655–658 (1994).Google Scholar
23. Groves, J. T., Boxer, S. G. & McConnell, H. M. Electric field-induced critical demixing in lipid bilayer membranes. Proc. Nat. Acad. Sci. 95, 935–938 (1998).Google Scholar
24. Meredith, J. C., Smith, A. P., Karim, A. & Amis, E. J. Combinatorial materials science for polymer thin-film dewetting. Macromolecules 33, 9747–9756 (2000).Google Scholar
25. Meredith, J. C., Karim, A. & Amis, E. J. High-throughput measurement of polymer blend phase behavior. Macromolecules 33, 5760–5762 (2000).Google Scholar
26. Wu, T., Efimenko, K. & Genzer, J. Combinatorial study of the mushroom-to-brush crossover in surface anchored polyacrylamide. J. Amer. Chem. Soc. 124, 9394–9395 (2002).Google Scholar
27. Bard, A. J. & Mirkin, M. V. Scanning Electrochemical Microscopy (Marcel Dekker, Inc., 2001).Google Scholar
28. Jambunathan, K., Shah, B. C., Hudson, J. L. & Hillier, A. C. Scanning electrochemical microscopy of hydrogen electro- oxidation. Rate constant measurements and carbon monoxide poisoning on platinum. J. Electroanal. Chem. 500, 279–289 (2001).Google Scholar
29. Lee, C., Miller, C. J. & Bard, A. J. Scanning electrochemical microscopy: Preparation of submicrometer electrodes. Anal. Chem. 63, 78–83 (1991).Google Scholar
30. Shah, B. C. & Hillier, A. C. Imaging the reactivity of electro-oxidation catalysts with the scanning electrochemical microscope. J. Electrochem. Soc. 147, 3043–3048 (2000).Google Scholar
31. Cussler, E. L. Diffusion: Mass Transfer in Fluid Systems (Cambridge University Press, 1997).Google Scholar
32. Watanabe, M. & Motoo, S. Electrocatalysis by ad-atoms part III. Enhancement of the oxidation of carbon monoxide on platinum by ruthenium ad-atoms. Electroanal. Chem. and Interfac. Electrochem. 60, 275–283 (1975).Google Scholar