Liquid phase catalytic exchange reactions are mainly used for separation of hydrogen isotopes from liquid water. Based on the carbon-supported Pt and Pt–Fe catalysts, different hydrophobic Pt and Pt–Fe catalysts were fabricated for use in such reactions. The characterization results indicated the Pt–Fe alloy was formed in the Pt 3 Fe/C catalyst prepared using a citric-acid-assisted NaBH 4 reduction method (CA-NaBH 4 ). However, there were more Fe oxide species and the Fe components existed independently in the Pt 3 Fe/C catalyst prepared by the modified microwave-irradiated ethyl glycol reduction procedure (MI). Performance tests demonstrated that the activities of the hydrophobic Pt–Fe catalysts with appropriate Fe/Pt ratios, using the MI method, were enhanced because of the addition of Fe. In contrast, the hydrophobic Pt 3 Fe catalyst prepared using the CA-NaBH 4 method had lower catalytic activity than pure Pt. Possible reasons were explained by reaction mechanisms of double routes of LPCE catalysis.