Ta-Based Catalyst Support for Proton Exchange Membrane Fuel Cell Applications

摘要

An ordered mesporous Colloid Imprinted Carbon with 80 nm sized pores (CIC80), a nitrided CIC80 (N-CIC80), and Ta oxynitride nanoparticles on nitrided CIC80 (TaO_xN_y NPs/N-CIC80) were synthesized and evaluated as possible supports for Pt electrocatalysts in PEMFC applications. Transmission electron microscopy images showed that they have the expected pore size and that the TaO_xN_y NPs are in the range of 5-20 nm in diameter. Potential stepping experiments revealed that the TaO_xN_y NPs/N-CIC80 composite exhibits the highest corrosion resistance in 0.5 M H_2SO_4, followed by N-CIC80 and then CIC80. Consistent with this, cyclic voltammetry revealed that the TaO_xN_y NPs/N-CIC80 composite gave the smallest increase in surface area after the potential stepping experiment, followed by N-CIC80 and CIC80. These results suggest that a nitrided carbon surface is more corrosion resistant than carbon alone, and that the TaO_xN_y NPs, which are themselves extremely stable, are conferring some of their stability to the carbon substrate.