Mesoporous Ti_(0.)5Cr_(0.5)N Supported PdAg Nanoalloy as Highly Active and Stable Catalysts for the Electrooxidation of Formic Acid and Methanol

摘要

We report a robust noncarbon Ti_(0.)5Cr_(0.5)N support synthesized by an efficient solid-solid phase separation method. This ternary nitride exhibits highly porous, sintered, and random network structure with a crystallite size of 20-40 nm, resulting in a high specific surface area. It is not only kinetically stable in both acid and alkaline media, but also electrochemically stable in the potential range of fuel cell operation. Two typical anode reactions, formic acid oxidation in acid media and methanol oxidation in alkaline media, are employed to investigate the possibility of Ti_(0.)5Cr_(0.5)N as an alternative to carbon. Bimetallic PdAg nanoparticles (~4 nm) act as anode catalysts for the two anode reactions. PdAg/Ti_(0.)5Cr_(0.5)N exhibits much higher mass activity and durability for the two reactions than PdAg/C and Pd/C catalyst, suggesting that mesoporous Ti_(0.)5Cr_(0.5)N is a very promising support in both acid and alkaline media.