Peter A. Ferrin1, Anand U. Nilekar1, Jeff Greeley2, Jan Rossmeisl3, and Manos Mavrikakis1. (1) Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, (2) Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, (3) Department of Physics, Center for Atomic-scale Materials Design (CAMD), Building 307, Technical University of Denmark, DK-2800, Lyngby, Denmark
Direct methanol fuel cells (DMFCs) show promise as energy conversion devices for multiple applications. However, several technical problems, such as the high overpotential associated with the anode reaction, limit the efficiency of DMFCs. In this work, we use periodic, self-consistent Density Functional Theory to calculate key aspects of the electrochemical potential energy surface for the anode reaction on the close-packed surface of 12 transition metals. We evaluate different reaction pathways and find an associated overpotential for each reaction on each surface studied. Using this information, we identify the free energies of key reactive intermediates, which can be used to determine the associated overpotential for this reaction on any surface. Finally, we identify alloy surfaces which may minimize the overpotential and therefore improve the DMFC efficiency.