Nano-sized Pt–NbOx supported on TiN as cost-effective electrocatalyst for oxygen reduction reaction
Natália de Freitas Daudt, Abhinav Poozhikunnath, Haoran Yu, Leonard J. Bonville, Radenka Marić
Abstract
Abstract 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.