Muhammad Falila Izzuddin Haqq, Karisma Pradina Putri, Muhammad Naufal Alhilmy, Moh Nadhif Mauluddin, Susi Nurul Khalifah, Lulu'atul Hamidatu Ulya, Saidun Fiddaroini
Catalytic upgrading of waste cooking oil to green diesel offers a practical approach for producing sustainable transportation fuels and reducing environmental pollution. In this study, mono- and bimetallic Ni and Co catalysts supported on γ-Al2O3 were synthesized via a sonication-assisted wet impregnation method to improve metal dispersion and metal–support interactions. The catalysts were evaluated in the deoxygenation of corn oil waste (COW) in a semi-batch reactor at 360 °C for 4 h under a nitrogen atmosphere. The physicochemical properties of the catalysts were characterized using SEM–EDX, XRD, FTIR, N2 adsorption–desorption (BET–BJH), ICP-OES, and H2-TPR analyses, confirming successful metal incorporation, improved dispersion, and enhanced reducibility for the bimetallic NiCo/γ-Al2O3 catalyst. The bimetallic system showed improved catalytic performance, achieving a 37.5% increase in liquid yield and reduced coke formation compared to γ-Al2O3. Product analysis based on semi-quantitative GC–MS indicates an increasing trend in relative hydrocarbon content (∼32.84%) and a relative increase in relative paraffin distribution (∼5.08%), suggesting enhanced deoxygenation performance. Gas-phase analysis, based on the relative quantification of CO and CO2 using GC–TCD, suggests that deoxygenation is likely governed by decarboxylation (DCO2) and decarbonylation (DCO) pathways under inert conditions. Catalyst stability evaluation, supported by reusability tests and thermogravimetric analysis (TGA), indicates that the bimetallic catalyst can suppress carbon deposition and maintain catalytic performance over multiple cycles. Overall, these findings suggest that sonication-assisted NiCo/γ-Al2O3 catalysts can enhance deoxygenation efficiency and improve green diesel production from corn oil waste, although further quantitative studies would be beneficial to fully elucidate the reaction mechanism. © 2026 Indian Chemical Society.
Chemistry Study Program, Science and Technology Faculty, Universitas Islam Negeri Maulana Malik Ibrahim, Malang, 65144, Indonesia; Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand; Chemistry Department, Faculty of Mathematic and Natural Science, Brawijaya University, Malang, 65144, Indonesia
