High temperature annealed (002) oriented WO3 nanoplatelets with uniform Pt decoration as durable carbon free anode electrocatalyst for PEMFC application

One of the major challenges we come across in the long term durability and stability of Proton Exchange Membrane Fuel Cells (PEMFCs) is the oxidation of the carbon based electrocatalyst or commonly said as carbon corrosion. Commercial Pt/C (46 wt%) is the most generally used carbon based electrocatalyst in PEMFCs which undergo degradation in its performance over long term operation. As an attempt to realize non carbon support in PEMFC, we have synthesized highly stable and durable metal oxide catalyst WO3 and uniformly decorated Pt nanoparticles (<= 20 wt%) on these WO3 nanoplatelets annealed at higher temperature with preferential orientation (002) plane. Hydrogen Oxidation Reaction (HOR) characteristics of Pt/WO3 has been studied using half-cell studies. It reveals that Pt/WO3-550 catalyst shows comparable performance to that of Pt/C in terms of limiting current density, onset potential due to its highly crystalline nature and ability to uniformly disperse Pt nanoparticles. The durability and stability of this HOR catalyst Pt/WO3-550 was confirmed by the Chromoamperometry (CA) studies conducted for 24h. The reduction in Electrochemical Surface Area (ECSA) for Pt/WO3-550 after CA was negligible (similar to 10%) when compared to Pt/C catalyst for the same loading of Pt in both cases. We fabricated Membrane Electrode Assembly (MEA) for the validation of single cell performances for Pt/WO3-350, Pt/WO3-450 and Pt/WO3-550 catalysts with a loading of 0.125mgcm(-2) at anode side of PEMFC. Maximum Power density of 430 mWcm(-2) is observed for Pt/WO3-550 at 50 degrees C. This showcases that Pt/WO3 under optimum conditions could be used as the best alternative for anode electrocatalyst and even on both sides as carbon free electrocatalyst for PEMFCs. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This article introduces a stable and durable metal oxide catalyst Pt/WO3 for Proton Exchange Membrane Fuel Cells (PEMFCs) to address carbon corrosion issues. The research findings demonstrate that Pt/WO3 exhibits comparable performance to commercial carbon-based catalyst Pt/C and maintains good stability after 24-hour testing.