Stabilizing Low-Iridium Anode Catalysts via Boron Carbon Nitride Supports for Efficient PEM Water Electrolysis

Abstract

The high cost and limited durability of iridium (Ir)-based anode catalysts are huge barriers for the large-scale applications of proton exchange membrane water electrolyzers (PEMWEs). Employing a conductive and corrosion resistant catalyst supports can mitigate these issues by maximizing the Ir utilization and long-term stability. This work reports a novel boron carbon nitride (BCN) catalyst support for Ir nanoparticles that exhibits improved oxygen evolution reaction kinetics and excellent stability in PEMWEs. Ir-BCN prepared via facile solid-state synthesis of BCN followed by Ir nanoparticles deposition via polyol synthesis shows a high oxygen evolution activity achieving an overpotential of 240 mV at 10 mA/cm2. More importantly, the Ir-BCN as anode catalyst layer in PEMWEs shows high performance and improved stability compared to IrOx-TKK based catalyst. The detailed voltage breakdown analysis revealed that the low kinetic and mass transport losses of Ir-BCN based catalyst layer contribute to the improved cell performance. Similarly, the corrosion test results also reveal a significantly low corrosion current for Ir-BCN than IrOx–TKK, highlighting its enhanced durability. This work highlights the combination of high conductivity, corrosion resistance, and scalable synthesis of BCN as a catalyst support for durable anode catalysts in PEMWEs