The oxygen reduction reaction (ORR) is the semi-reaction that occurs at the cathode in technologies like the polymer electrolyte membrane fuel cells (PEMFCs). These devices are notable for their high efficiency in converting chemical energy to electricity, compact design, and potential for near-zero emissions, making them essential for clean energy production. However, the current state-of-the-art electrocatalysts for PEMFCs predominantly rely on platinum (Pt/C), which poses significant barriers to widespread commercialisation due to platinum’s limited availability, high cost, and high volatility. Consequently, developing novel, more affordable catalysts with improved activity and enhanced durability represents a relevant research focus in PEMFC technology. Among the most promising alternatives are non-precious-metal “M-N-C” catalysts, which incorporate metal ions (such as Fe, Co, etc.) within a nitrogen-doped mesoporous carbon support.