Synthesis of nano-sized Pt/C via zeolite-templating method and its application to the cathode catalyst in PEMFC

Well-dispersed nano-sized Pt/C with less agglomeration was successfully synthesized via zeolite-templating method. Depending on the ramping rate such as 0.1 °C/min, 0.2 °C/min and 2.0 °C/min for the decomposition of Pt(NH3)4+ within zeolite pore channel, the degree of agglomeration of Pt particles was significantly affected. The Pt content of various nano-sized Pt/C synthesized via zeolite-templating method using different ramping rate is in the range of 37–49% based on Pt/C only excluding water content. The TEM images clearly show that the size of Pt/C formed within zeolite pore channel is highly uniform throughout pore channels indicating the steric effect exerted by zeolite pore channel with the restriction of agglomeration of Pt particles. For zeolite-eliminated Pt/C, however, the TEM images show that the degree of agglomeration of Pt particles was significantly increased with the ramping rate, resulting in the formation of larger Pt particles. The BET surface areas of Pt/C are inversely proportional to the ramping rate. Finally, the results show that the MEA fabricated with Pt/C obtained at low ramping rate would lead to much better cell performance compared to that fabricated with commercial Pt/C. It strongly suggests that the cathode fabricated with well-dispersed Pt particles would provide more electrochemical active sites, thus leading to the enhancement of cell performance.