Enhanced Alkaline Water Electrolysis with PrBa0.5Sr0.5Co1.5Fe0.5O5+δ-IrO2 Composite: Synergistic Catalytic Performance via Electronic Structure Modulation

Abstract

Alkaline water electrolysis (AWS) is a promising technology for hydrogen production, but the low performance of oxygen evolution reaction (OER) electrodes leads to high energy consumption. Enhancing OER efficiency is essential for reducing energy barriers and improving system performance. In this study, it develops a composite catalyst of PrBa_0.5Sr_0.5Co_1.5Fe_0.5O_5+δ and IrO₂ (PBSCF-Ir), with a surface area of 18.68 m²g⁻¹. The PBSCF-Ir composite exhibits a low overpotential of 312 mV at 10 mA cm⁻² and stability over 300 h. In water splitting tests, it achieves a lower cell voltage (1.95 V at 500 mA cm⁻²) compared to pure IrO₂. X-ray photoelectron spectroscopy reveals a 1 eV blueshift in Co 2p energy levels, indicating modified electronic structures. Density functional theory calculations show that IrO₂ shifts the d-band centers of Co and Fe, enhancing electrophilicity, OH⁻ affinity, and OER activity. This study highlights the PBSCF-Ir composite as an efficient and durable catalyst for AWS, thereby addressing the need for sustainable hydrogen production.