Synergistic effect of NiO–CuO bimetallic catalysts on efficient conversion of crude palm oil to biogasoline

Developing efficient catalysts for converting crude palm oil (CPO) into renewable biogasoline remains a key challenge due to the complex structure of triglycerides and free fatty acids. NiO–CuO bimetallic have attracted attention as a cost-effective and selective catalyst for biogasoline production. Herein, NiO–CuO catalysts with varying NiO:CuO molar ratios (1:0.5, 1:1, and 1:2) were synthesized via a simple co-precipitation method and applied for catalytic cracking of CPO. Pyridine-FTIR and NH₃-TPD analyses revealed that the NiO–CuO (1:1) catalyst exhibits a well-balanced distribution of Lewis and Brønsted acid sites with the highest total acidity. Catalytic cracking proceeded through β-scission, decarboxylation, and secondary cyclization/aromatization reactions, efficiently converting triglycerides into hydrocarbons predominantly in the C₅–C₁₁ range. The highest biogasoline yield of 83 % was achieved using the NiO–CuO (1:1) catalyst under mild conditions (380 °C, 2 h). A proposed catalytic cracking mechanism is presented to support the observed results. Importantly, this study demonstrates that tuning the NiO:CuO ratio effectively controls surface acidity and redox properties, providing an energy-efficient and highly selective route for converting CPO into renewable gasoline-range hydrocarbons. These findings position NiO–CuO (1:1) as a promising catalyst for sustainable biogasoline production.