Nano-fabrication and characterization of new conceptual platinum catalysts for low temperature fuel cells

In order to prepare the carbon supported platinum catalysts with high activity, high loading and high distribution, novel sub-substrate methods (a novel incipient wetness and impregnation methods) were used. As a substrate, the acid-treated Vulcan X (VC-X) and Ketjen Black (KB), which have large surface areas, were used and as a sub-substrate, fumed silica was used for the increment of surface area. All prepared catalysts showed the platinum lattice structure clearly and had a small particle size range of 2-5 nm. They also had face-centered cubic structures and showed a fine distribution in spite of high loading. From the TGA and ICP-AES analyses, it can be confirmed that all prepared catalysts showed similar compositions to the expected values within the error range of 0.5%. In case of the prepared catalyst with novel incipient wetness method, a large amount of platinum was located on the carbon surface compared to its loading level. This phenomenon is related to the active surface area, which participates in practical fuel cell reactions. In the Cyclic voltammetry (CV) experimental, Pt₃₃/KB catalyst showed a large electrochemical surface area of 102 m²/Pt g. In addition, the unit-cell performance of this catalyst at 0.75-0.6 V showed higher values compared to the commercial catalyst. The merits of this experiment were to construct the mass production process with very simple methods and to be able to increase the yields of platinum utilization.