Platinum Fuel Cell Nanoparticle Syntheses: Effect on Morphology, Structure and Electrocatalytic Behavior

Because of high cost and low availability of platinum, which yet remains unavoidable as catalyst in proton exchange membrane fuel cells for achieving acceptable electric performances, numerous synthesis methods of Pt nanoparticles were developed. The decrease of the particle size in a certain extent leads to a decrease of the noble metal content in the fuel cell electrodes and also to an increase of their real surface area. Physical methods such as plasma sputtering of metals [Brault et al., 2004; Caillard et al., 2007, Cho et al., 2008], laser ablation [Perrière et al., 2001; Boulmer et al., 2006], metal organic chemical vapor deposition [Billy et al., 2010], etc., have been and are still developed for preparing low loaded platinum based electrodes for Proton Exchange Membrane Fuel Cell (PEMFC). Although such methods present important interests due to the high control of metal deposition parameters, they involve also important material losses in the deposition chamber and on the electrode mask. Metal electrodeposition can also be classified as a physical method of electrode preparation [Chen et al., 2003; Ayyadurai et al., 2007]. This method consists in the electrochemical reduction of a metallic salt on an electron conductive support. It is then possible by varying the current or potential sequence applied to the electrode to control or at least to change the structure of the catalyst. However, the faradic yield is often very low because hydrogen evolution can occur as soon as platinum is deposited on the substrate [Coutanceau et al., 2004].