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

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–NbOx catalyst supported on TiN nanoparticles as an alternative electrocatalyst for the oxygen reduction reaction (ORR). The use of Pt–NbOx 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–NbOx 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∙mgPt−1 and a specific activity of 283 μA∙cmPt−2 at 0.9 V. These results demonstrate that Pt–NbOx on TiN electrocatalyst has the potential for replacing Pt/C cathode in PEMFC.

How to appropriately assess the oxygen reduction reaction activity of platinum group metal catalysts with rotating disk electrode

“…As shown in Figure 1 , a typical TF-RDE setup usually involves three electrodes, i.e., working electrode (WE), counter electrode (CE) and RE. WE potentials obtained via various REs (like mercury-mercurous sulfate electrode [MSE] ( Daudt et al., 2020 ; Shen et al., 2016 ), saturated calomel electrode ( Fang et al., 2019 ; Liu et al., 2017 ), et al.) are usually converted to potentials of RHE scale ( Jerkiewicz, 2020 ; Niu et al., 2020 ) for the convenience of comparison between different systems.…”

Durable Electrocatalyst Support Materials Based on N-Doped Mesoporous Carbon Nanofibers with Titanium Nitride Overlay Coating for High-Performance Proton Exchange Membrane Fuel Cells

“…42 The characteristic XRD peaks of TiN thin films present on TiN/g-C 3 N 4 /m-PCNFs exhibited at 43 and 65°, corresponding to planes (200) and (220) reflections JCPDS (38−1420). 43 Although TiN also may have the possibility to get oxidized to TiNO x with a similar crystal system, it is difficult to distinguish TiN and TiNOx from XRD peaks. Interestingly, both TiN and TiNOx are proven materials for improving ORR activity and TiN has a strong affinity for Pt, leading to robust chemical bonding between Pt nanoparticles and mitigates Pt aggregation.…”

Phase, Microstructure, and Tensile Strength of Al6351-Graphite-WC Hybrid Metal Matrix Composites

“…Where k is known as the Scherrer constant, λ is the wavelength of the X-ray beam, β is the FWHM of the peak and θ is the Bragg angle. 39 The Scherrer equation is utilized to estimate the crystal and the resulting fluctuation is graphically represented in Fig. 2.…”