The oxygen evolution reaction (OER) is a critical bottleneck in the commercial evolution of anion exchange membrane water electrolyzers (AEMWEs). As a potential substitute for the scarce and expensive noble metal-based electrocatalysts typically used to improve the OER activity, here amorphous NiFe oxides with varying Ni/Fe ratios were synthesized using a simplistic and cost-effective sol–gel method. After carefully investigating the structural and morphological attributes of the derived electrocatalysts, their OER activities were analyzed by acquiring the half-cell measurements. First, the influence of the electrochemical ink formulation and additives on the activity of the electrocatalyst was studied, followed by elucidating the electrocatalyst loading to configure the working electrode on the rotating disk electrode (RDE). By comparing the activities of different synthesized NiFe oxides, it was observed that Ni_0.75Fe_0.25O delivers the peak performance with a minimum overpotential of ca. 290 mV. Therefore, the aforementioned sample was utilized to configure the anode electrode for a lab-scale AEMWE, achieving 3.7 A cm⁻² at 2 V and 80 °C while demonstrating promising stability trends.

In this work, platinum group metal-free (PGM-free) electrocatalysts were synthesized, characterized, and tested for hydrogen evolution reaction (HER). These materials were mono-, bi- and trimetallic Ni-based electrocatalysts with the addition of a second or a third transition metal (TM), such as iron and cobalt. TM–phthalocyanine (TMPc) was used as a metal precursor, mixed with a conductive carbon backbone and subjected to pyrolysis under controlled temperature and atmosphere conditions. Two temperatures of pyrolysis (600 °C and 900 °C) were used. The effect of TM loading in the precursors, different pyrolysis temperatures on the surface chemistry and morphology, and electrocatalytic activity towards HER were evaluated. The increase of NiPc in the initial mixture is beneficial to improving the electrocatalytic activity. The addition of a second and a third metal reflects positively on the HER performance. Interestingly, the pyrolysis temperature influences both the formation and growth of the nanoparticles, and this information is supported by high-resolution transmission electron microscopy (HR-TEM) and light synchrotron X-ray absorption spectroscopy (XAS) measurements.