Hydrogen is gaining traction as a viable energy carrier through global decarbonization initiatives seen worldwide. However, it is primarily produced through steam methane reformation, which produces substantial CO₂. An alternative approach, water electrolysis, can produce green hydrogen when integrated with renewable electricity sources. Significant progress has been made in established water electrolysis technologies such as alkaline water electrolyzers (AWE) and proton exchange membrane water electrolyzers (PEMWE). Anion exchange membrane water electrolyzers (AEMWE) are the natural next step to realize cost effective hydrogen. For an AEMWE to work well, highly active catalysts are required to overcome the substantial overpotentials necessary for the kinetically sluggish oxygen evolution reaction (OER).

This work aims to explore halide-assisted NiFe-based catalysts to improve catalytic activity for the OER. The catalysts synthesized were tested in full cell electrolyzers with a PtRu/C hydrogen evolution reaction (HER) catalyst to eliminate the HER impact. Achieving commercially feasible voltages and current densities relies on the synergy between the catalysts, optimal electrode design, membrane, ionomer, and conductive porous substrates. Here, we have demonstrated that these halide-assisted NiFe-based catalysts enabled a current density of 2 A/cm² operating under 2 V for over 100 h in a dilute alkaline electrolyte. Much work remains to further improve the performance and long-term durability of an AEMWE.