Electrochemical Conditioning-Driven Activation of Alkaline Electrolyzer for Sustainable Hydrogen Generation

Developing efficient and inexpensive electrocatalysts for alkaline water electrolysis is essential for sustainable hydrogen production. The NiFe-LDH electrocatalyst was prepared by the electrodeposition method and subjected to electrochemical conditioning at a current density of 20 mA cm −2 for 24 h in 6 M KOH electrolyte using both an AWE test cell and 4-cell stack configuration. The electrochemically conditioned (NiFe-LDH_C) AWE test cell/stack can result in better performance by achieving 233 mA cm −2 current density, whereas 177 mA cm −2 with an unconditioned (NiFe-LDH) cell at unit cell voltage of 1.9 V and 30 °C. This study further examines the impact of electrochemical conditioning duration (0.5, 3,6,24, and 30 h) on performance enhancement. The performance evaluation includes polarization curves to measure catalytic activity, temperature-dependent experiments to examine how the thermal variation of electrolyte influences the AWE test cell and 4-cell stack efficiency, and extended stability tests that simulate continuous operation to assess durability over time. To simulate the dynamic operating stresses of renewable-powered system, the accelerated stress test through high-load (400 mA cm −2 ) and low-load (200 mA cm −2 ) cycling tests was conducted. The conditioned AWE test cell/stack revealed better performance retention and minimal variation.