Highly Active and Stable Al-Doped NiFe Self-Supported Oxygen Evolution Reaction Electrode for Alkaline Water Electrolysis

Abstract

Alkaline water electrolysis (AWE), a predominant technology for large-scale industrial hydrogen production, faces limitations in commercialization owing to the inadequate catalytic activity and stability of oxygen evolution reaction (OER) electrocatalysts. This study introduces a NiFeAl self-supported electrode characterized by high activity and stability for the OER and outlines a rational design strategy for NiFe (oxy)hydroxide-based self-supported electrodes. The introduction of Al, a ternary dopant with relatively low electronegativity and a small ionic radius, into the NiFe electrode effectively controls the adsorption energy of O-intermediates and facilitates the deprotonation of adsorbed OH*, thereby accelerating the OER. Remarkably, the NiFeAl self-supported electrode demonstrates approximately 50% enhanced operational activity (0.71 A cm^–2 at 1.8 V) compared to NiFe alongside exceptional stability (>72 h at 0.6 A cm^–2) in OER within an AWE single cell. These findings highlight the significant potential of the NiFeAl electrode for application in AWE for efficient, large-scale hydrogen production.