Mechanism for Size Control Using Colloidal Synthesis Methods

1 Mechanism for Size Control Using Colloidal Synthesis Methods 

A number of fuel cell catalysts have been synthesized in this maimer, such as Pt colloids, Pt/Sn colloids, and Pt/Ru colloids of different Pt to Ru ratios. A drawback of the Boennemann synthesis method is that oxidative removal of the stabilizer molecule requires temperatures higher than 300 °C [69]. High-temperature treatment of Pt-based catalysts should be avoided as changes in the structure, namely preferential surface segregation of Pt or RUO2, typically take place (this is further discussed in Section 9.4.1). To the best of our knowledge the Boennemann method has not been used to make catalysts of the same composition but different sizes. 

More reeently, a method utilizing different amounts of a large stabilizer has been reported to make Pt and Pt/Ru eatalysts of controlled size [70]. The catalysts were 

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