Pt CoN supported on TiN-modified carbon nanotubes (Pt CoN/TiN–CNT) as efficient oxygen reduction reaction catalysts in acidic medium

Herein, new catalysts for the oxygen reduction reaction (ORR) (PtCoN nanoparticles supported on TiN–carbon nanotubes (CNTs)) were successfully prepared via the simple polymerized complex method and heat treatment in NH3. Through this facile two-step synthesis, metal chlorides were first transformed to the corresponding oxides, then reduced to metal particles or nitrides. The synthesized PtCoN/TiN–CNT electrocatalysts showed excellent electrochemical activity for oxygen reduction and high tolerance against methanol in acidic medium. The ORR onset potential of Pt0.3CoN/TiN–CNT (0.812 V vs. RHE) is higher than that of 40 wt% commercial Pt/C (0.789 V vs. RHE) due to the synergistic effect between nano-platinum particles and metal nitrides. The TiN-coated CNT support provided high electron transfer rate and catalytic tolerance in methanol solution. The number of transferred electrons was examined by rotating ring-disk electrode measurements, which concurred with the result of the Koutecky–Levich equation for a four-electron mechanism.