Methanol has been viewed as a possible alternative fuel source for low-temperature fuel cell applications. In direct methanol fuel cells (DMFCs), methanol is oxidized at the anode of a polymer-electrolyte-membrane (PEM) fuel cell to form CO2, protons and electrons. These fuel cells have many of the same advantages as the traditional H2-PEM, fuel cells, including high power density and theoretical efficiency. Furthermore, the storage issues limiting wide use of H2 fuel cells can be avoided. However, still, the economic costs of Pt-based catalysts are prohibitive to commercial viability, necessitating the development of novel anode materials. In order to engineer new materials for this reaction, it is essential to understand the fundamental challenges in the electro-oxidation reaction mechanism. Using first-principles, density functional theory (DFT) calculations, and a simplified model of the electro-chemical environment,1 we have investigated the mechanism for methanol electro-oxidation on close-packed facets of transition metal catalysts2, 3 Further insights are gained by applying first-principles molecular dynamics to a more elaborate description of the electrochemical environment.4
1. NÝrskov, J. K.; Rossmeisl, J.; Logadottir, A.; Lindqvist, L.; Kitchin, J. R.; Bligaard, T.; Jonsson, H., Origin of the overpotential for oxygen reduction at a fuel-cell cathode. Journal of Physical Chemistry B 2004, 108 (46), 17886-17892.
2. Ferrin, P.; Mavrikakis, M., Structure Sensitivity of Methanol Electrooxidation on Transition Metals. Journal of the American Chemical Society 2009, 131 (40), 14381-14389.
3. Ferrin, P.; Nilekar, A. U.; Greeley, J.; Mavrikakis, M.; Rossmeisl, J., Reactivity descriptors for direct methanol fuel cell anode catalysts. Surface Science 2008, 602 (21), 3424-3431.
4. Sugino, O.; Hamada, I.; Otani, M.; Morikawa, Y.; Ikeshoji, T.; Okamoto, Y., First-principles molecular dynamics simulation of biased electrode/solution interface. Surface Science 2007, 601 (22), 5237-5240.