Controlled synthesis of CO-tolerant Pt3Sn/C anode electrocatalysts for polymer electrolyte membrane fuel cells

摘要

Reducing the amount of Pt along with increasing the metal dispersion is a key requirement for the implementation of fuel cells. CO tolerance and stability of the anode electrocatalysts also has to be improved, as the hydrogen fuel generally contains CO impurity that poisons Pt. Pt-Sn bulk alloys are among the most studied bimetallic systems for fuel cell applications [1]. Sn has a promotional effect in the electrooxidation of CO_(ad) by providing the necessary OH_(ad) species at less positive potentials than Pt. Exclusive formation of supported Sn-Pt alloy phases with different Pt/Sn ratios can be achieved by using Controlled Surface Reactions (CSRs) between hydrogen adsorbed on Pt sites and tetraethyltin (Sn(C2Hs)4) [1,2].