Highly Efficient and Durable Anion Exchange Membrane Water Electrolyzer Enabled by a Fe–Ni3S2 Anode Catalyst

Abstract

Anion exchange membrane water electrolyzer (AEM‐WE) is a promising approach to producing green hydrogen using renewable energy. However, most of the reported AEM‐WEs still use platinum‐group metal‐based catalysts and the performance is far beyond unsatisfactory. Particularly, developing highly active, durable, and earth‐abundant metal‐based oxygen evolution reaction (OER) catalysts is essential to improve energy efficiency and reduce the costs of AEM‐WE. Herein, Ni2Fe8/Ni3S2/NF catalyst is fabricated in situ on nickel foam by a simple one‐pot hydrothermal reaction. The as‐prepared anode OER catalyst exhibits current densities of 500 and 1000 mA cm−2 at an overpotential (η) of 279 and 302 mV, superior to the performance of noble metal‐based catalysts (IrO2, RuO2). Coupled with Ni4Mo/MoO2/NF, the resulting single‐cell AEM‐WE displays high performance (1.65 V @ 1 A cm−2) and high durability (100 h @ 1 A cm−2), outperforming most of the reported AEM‐WEs assembled by non‐noble metal‐based catalysts. Additional characterization of the post‐test anode using different spectroscopic techniques further proved that the Ni2Fe8/Ni3S2/NF is a highly efficient and robust anode in the AEM‐WE device.