<p>Understanding active phase evolution and redox behavior is critical for developing efficient non-noble catalysts for cracking waste cooking oil into renewable hydrocarbons. In this study, activated carbon supported bimetallic Ni–Fe oxide catalysts with varying Ni/Fe loading ratios were synthesized via incipient wetness impregnation at a constant total metal loading of 15 wt%. The catalyst activity was tested in a fixed bed reactor at 450&#xa0;°C. Among the evaluated catalysts, 10Ni–5Fe/AC demonstrated the optimal performance, yielding the highest liquid yield (67.08 wt%) and alkane selectivity (55%) while minimizing coke formation (2.74 wt%). This enhanced catalytic efficiency is attributed to a synergistic combination of high surface area (315 m² g^− 1), balanced acid site strength, and the optimal formation of a NiFe₂O₄ spinel phase. The structural coexistence of NiFe₂O₄ and mixed-valence Fe species provided the critical redox flexibility necessary to drive selective deoxygenation. Acid‑treated support with optimal Ni/Fe ratio was found to retain crystalline metallic species after four recycles, sustaining robust structure and reasonable yields. This study highlights how bimetallic ratio governs texture, acidity and active phase in supporting the design of cost-effective and high-performance catalysts for sustainable biofuel production.</p>