(499d) Perovskite-Based Catalysts for Dirct Alcohol Fuel Cells

Aidong Lan and Alexander S. Mukasyan

Department of Chemical and Biomolecular Engineering, Center for Molecularly Engineered Materials, University of Notre Dame Notre Dame, IN 46556 alan@nd.edu; amoukasi@nd.edu

One of the drawbacks of the alcohol-based fuel cells is the poisoning of the anodic catalyst. Among several different materials the use of the Pt-based bimetallic alloys has been most successful to solve this problem. In our studies we suggest a different approach for developing of the effective low cost multifunctional catalysts for alcohol-based fuel cells. It is proposed that mixed conductor complex oxides, some of which are excellent catalysts for CO oxidation, could be the alternative materials for fuel cells application. In our previous work [Deshpande K., Mukasyan A.S. and Varma A., J. Power Sources. 2006, in print] we have demonstrated a novel methodology for finding the effective perovskite-based catalysts. It was shown that SrRuO3 catalyst performed promising activity for methanol electro-oxidation in the conditions similar to those for DMFCs. It was also revealed that direct incorporation (during combustion reaction) of small amount of platinum on the perovskite surface leads to significant enhance of its catalytic activity. In this work utilizing a screening strategy featuring energy efficient and rapid solution combustion (SC) synthesis technique for catalyst production, and the high throughput NuVant system for testing of their electro catalytic activities, a library of conductive perovskites (ABO3; A=Ba, Ca, Sr, La, Fe) were synthesized and tested for methanol and ethanol electro-oxidation. It was shown that all these mixed-conductor complex perovskites with ruthenium on B-site are promising candidates for development of the effective catalysts for both fuels. However, two families, i.e. LaRuO3 and SrRuO3, possess the best performance. Composite perovskite-Pt catalysts were also synthesized directly by SC method. Optimum amount of noble metal (Pt) was found to be ~10wt.%. These catalysts showed similar apparent catalytic activity to standard Pt-Ru alloy, which contains 4 times more platinum. The possible mechanism of such behavior for composite catalysts is discussed. This encouraging result suggests that the multifunctional catalysts prepared by combustion technique may hold a key for cost friendly solution of effective for DMEFC and DEFC design. Acknowledgement. This work was supported by the U.S. Army CECOM RDEC through Agreement AAB07-03-3-K414. Such support does not constitute endorsement by the U.S. Army of the views expressed in this publication.