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.