Exploring the influence of composition and morphology on the oxygen evolution reaction performance of Co-based catalysts

Efficient catalysts for the oxygen evolution reaction (OER) are essential for advancing renewable energy technologies. This study focuses on the synthesis and characterization of CoxPy, CoO, CoP, NiCoP, and NiCo/C nanoparticles as catalysts for the oxygen evolution reaction (OER). The CoxPy nanoparticles exhibited a sea-urchin-like morphology, providing a high surface area for electrocatalytic activity. Other catalysts exhibited distinct morphologies, including spherical particles and porous structures. Characterization techniques, such as transmission electron microscopy and X-ray diffraction, confirmed the morphology and composition of the synthesized nanoparticles. The electrocatalytic performance of the catalysts was evaluated through polarization curve measurements, and a microkinetic steady-state model based on the Electrochemical Oxide Path was developed to understand the OER mechanism. The impact of adventitious Fe on catalyst activity was also investigated, revealing the high sensitivity of CoxPy to Fe. The findings suggest the dominance of the Electrochemical Oxide Path in the OER mechanism for all catalysts, with NiCoP showing the lowest onset potential.