Nano-sized Pt–NbO _x supported on TiN as cost-effective electrocatalyst for oxygen reduction reaction

Proton exchange membrane fuel cells (PEMFC) play a key role for sustainable energy; however, catalyst degradation remains one of the main challenges for competing with traditional energy technologies. The Pt/C commercially available electrocatalysts are susceptible to Pt dissolution and carbon support corrosion. In this context, we design a Pt–NbO_x catalyst supported on TiN nanoparticles as an alternative electrocatalyst for the oxygen reduction reaction (ORR). The use of Pt–NbO_x reduces materials’ costs by lowering the required platinum loading and improving catalyst performance. The TiN support is selected to improve support stability. The electrocatalyst is successfully synthesized by a one-step flame spray process called reactive spray deposition technology. Electrocatalyst with two different very low Pt loadings (0.032 mg cm⁻² and 0.077 mg cm⁻²) are investigated and their performance as cathode is evaluated by the rotating disk electrode method. The new electrocatalyst based on Pt–NbO_x supported on TiN has ORR performance that is comparable to the state-of-the-art Pt/C electrocatalyst. A half-wave potential of 910 mV was observed in the polarization curves, as well as a mass activity of 0.120 A∙mg_Pt⁻¹ and a specific activity of 283 μA∙cm_Pt⁻² at 0.9 V. These results demonstrate that Pt–NbO_x on TiN electrocatalyst has the potential for replacing Pt/C cathode in PEMFC.