Mesoporous TiN as a Noncarbon Support of Ag-Rich PtAg Nanoalloy Catalysts for Oxygen Reduction Reaction in Alkaline Media

There has been growing interest in noncarbon supports for fuel cell reactions, especially for the oxygen reduction reaction (ORR) in alkaline media. Herein, we report a robust mesoporous titanium nitride (TiN) which is not only kinetically stable in alkaline media, but also electrochemically stable in the potential range of fuel cell operation. This binary nitride exhibits an order of magnitude higher electronic conductivity than carbon black. Bimetallic Ag-rich PtAg nanoalloy is selected as the catalyst for the ORR in alkaline media due to their superior activity and relatively low cost. TiN-supported Pt1Ag9 nanoalloy catalysts are synthesized by a new and efficient approach with KEt3BH as reducing agent and THF as solvent. Pt1Ag9/TiN exhibits much higher mass activity and durability for the ORR in alkaline media than Pt1Ag9/C, Pt/C and Ag/C catalysts, suggesting that mesoporous TiN is a very promising support in alkaline media.