Synthesis of Pt/C Catalysts through Reductive Deposition: Ways of Tuning Catalytic Properties



Characteristic features of Pt/C catalysts prepared through reductive deposition from an aqueous solution have been investigated. The carbon support was found to act as an effective nucleating agent and to ensure the formation of small and predominantly nonaggregated Pt particles, probably through a preliminary formation of oxide nuclei on the carbon surface. The deposition rates could be high enough to provide the location of Pt nanoparticles near the external surface of the support and outside micropores. The depositions onto bare carbon supports and Pt/C samples presynthesized by using another method proved equally effective, which thus opened a route to various types of metal distribution. With the same metal precursor, reductant, and base (H2PtCl6, NaOOCH, Na2CO3), catalytic properties could be influenced through the support, Pt loading, and deposition conditions. In the oxidation of isopropyl alcohol as a model test reaction, alcohol conversion could be as high as 99.7 % and turnover frequencies 80 000 h−1 [H2O, O2, 1 bar (100 kPa), 30 °C].