Nafion-stabilised platinum nanoparticles supported on titanium nitride: An efficient and durable electrocatalyst for phosphoric acid based polymer electrolyte fuel cells

Abstract

Nafion derived platinum nanoparticles were produced and successfully anchored on titanium nitride (TiN) support (Pt/TiN) and its suitability for phosphoric acid based polymer electrolyte membrane fuel cells is reported. Electrochemical cycling of Nafion stabilised Pt/TiN electrocatalyst exhibits good stability, durability and better electrocatalytic activity than the traditionally employed carbon supported Pt (Pt/C). Platinum supported on TiN exhibits better oxygen reduction reaction (ORR) activity as compared to carbon black (Vulcan XC 72). Nafion stabilised Pt/TiN shows a positive shift of 20 mV in half-wave potential measured from ORR polarisation curve in relation to Pt/C. Nafion stabilised Pt/TiN shows approximately two-fold increase in mass and specific activities than the Pt/C calculated from ORR data at 0.9 V. The improved durability of Pt/TiN catalyst arises from Nafion layer surrounding the Pt nanoparticles and corrosion resistant TiN support. Transition metal nitride based electrocatalysts are more active for cathode due to synergistic effect, which is observed in oxygen reduction reaction.