Atomic Layer Deposition Preparation of Pd Nanoparticles on a Porous Carbon Support for Alcohol Oxidation (original) (raw)

Direct alcohol fuel cells (DAFCs) are promising energy sources for low-power demand devices such as laptops and mobile phones. However, the reaction rate of sluggish alcohol oxidation at the anode is still one of the key factors preventing their commercialization. The reaction rate can be enhanced in alkaline media, 2À5 and the interest in alkaline DAFCs has recently increased because of the development of anion exchange membranes. 6À9 For further enhancement, alcohol oxidation noble metals can be used as catalysts. In acidic media, platinum is most commonly applied as an electrocatalyst by itself or as an alloy; however, in alkaline media palladium has also shown high activity, especially for ethanol and isopropanol oxidation. These alcohols are interesting alternatives to the widely used methanol because of their lower crossover rate, 12,13 higher boiling points, lower toxicity, and high performance in preliminary fuel cell tests. Currently, most noble metal catalysts used in fuel cell applications are produced using a liquidÀsolid nanoparticle synthesis that results in inhomogeneous catalyst materials that affect dramatically the particle size distribution and electrochemically active surface area (EASA) of the catalyst. Because of the high cost and low availability of noble metals the loading on the catalyst must be decreased if DAFCs are to compete with other power sources in commercial applications.