| Abstract [eng] |
In modern society, there is an increasing search for efficient and environmentally friendly methods of electricity generation to reduce the demand for fossil fuels. One of the most promising alternatives are hydrogen technologies, which characterized by accessibility, sustainability, and broad industrial applicability. Renewable energy sources such as solar, wind, and water are still insufficient to fulfill the growing demand for electricity, therefore, the importance of fuel cells in the energy and economic sectors is rapidly increasing. In order to improve alternative electricity sources, scientific research is being conducted, and efficient fabrication methods are being developed for Proton Exchange Membrane Fuel Cells (PEMFCs). One of the primary research aims are to reduce the application of expensive noble metals in catalysts or completely replace them with more cost effective alternatives such as non-noble metals, thereby decreasing production costs and improving fuel cell performance. Electrochemical water splitting (EWS) process is a promising and sustainable method for hydrogen production, based on the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). This ultra-clean hydrogen is suitable for use in low-temperature Proton Exchange Membrane Fuel Cells (PEMFCs). For large-scale application of the EWS process, are essential efficient electrocatalysts, noble metal catalysts, such as platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), and rhodium (Rh), exhibit high catalytic activity, but their high cost and limited availability restrict wider application. In order to reduce production costs, recently, cost-effective alternatives of non-noble metals and carbon composites are being developed, which demonstrate excellent catalytic properties and have the potential to replace expensive noble metal catalysts. This study investigated the formation of catalytic materials based on carbon catalysts synthesized from wood and their modification with cobalt and chromium oxide nanoparticles using the hydrothermal synthesis method. The electrocatalytic activity of the produced catalysts was evaluated using Linear Sweep Voltammetry (LSV) for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The surface morphology, structure, and composition of the produced catalysts (Co₃O₄, Cr₂O₃, and Co₃O₄-Cr₂O₃) were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) methods. It was established that the synthesized Co₃O₄, Cr₂O₃, and Co₃O₄-Cr₂O₃ particles agglomerated in all cases, and the resulting agglomerates consisted of small particles of various sizes, approximately 2–11 µm in size. Notably, the introduction of N-doped carbon into the synthesized particles improved the electrocatalytic properties of the catalysts. Consequently, the Co₃O₄/NC catalyst exhibited the highest electrocatalytic activity for the hydrogen evolution reaction (HER), while the Co₃O₄-Cr₂O₃/NC catalyst demonstrated higher electrocatalytic activity for the oxygen evolution reaction (OER). Meanwhile, Cr₂O₃ and Cr₂O₃/NC catalysts were inactive for both HER and OER reactions. Thus, the synthesized Co₃O₄, Co₃O₄/NC, Co₃O₄-Cr₂O₃, and Co₃O₄-Cr₂O₃/NC catalysts are innovative/potential materials for hydrogen and oxygen evolution reactions in an alkaline medium. |
