Catalytic Activity of Hydrophobic Pt/C/PTFE Catalysts of Different PTFE Content for Hydrogen-Water Liquid Exchange Reaction

10％Pt/C catalysts were prepared by liquid reduction method. PTFE and Pt/C catalysts were adhered to porous metal and hydrophobic Pt/C/PTFE catalysts were prepared. The structure and size of Pt crystal particles of Pt/C catalysts were analyzed by XRD, and their mean size was 3.1 nm. The dispersion state of Pt/C and PTFE was analyzed by SEM, and they had good dispersion mostly, but PTFE membrane could be observed on local parts of Pt/C/PTFE surface. Because of low hydrophobicity, Pt/C/PTFE catalysts have low activity when the mass ratio of PTFE and Pt/C is 0.5∶1, and their catalytic activity increases markedly when the ratio is 1∶1. When the ratio increases again, more Pt active sites would be covered by PTFE and interior diffusion effect would increase, which result in the decrease of catalytic activity of Pt/C/PTFE. By PTFE pretreatment of porous metal carrier, the activity of Pt/C/PTFE catalysts decreases when the mass ratio of PTFE and Pt/C is 0.5∶1, and their activity decreases when the mass ratio is 1∶1.