Preparation and Characterization of Zeolite Supported Fluoropalladium Oxalate Catalyst for Hydrodeoxygenation of Oleic Acid into Paraffinic Fuel

Oleic acid (OA) was hydrodeoxygenated in this study using zeolite-supported fluoropalladium oxalate (FPdOx/Zeol) catalyst. The FPdOx/Zeol was prepared via a pH controlled simple dissolution method and characterized with thermal gravimetric analysis, energy dispersive X-ray, X-ray fluorescence, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Brunauer–Emmett–Teller techniques. The results showed that the deposited Pd particle was highly dispersed on the zeolite (Zeol) because of the presence of oxalate ligands and proper calcination. This observation was corroborated by the transformation of the Zeol support from crystalline into amorphous in FPdOx/Zeol as seen in the XRD and scanning electron microscopy results. The best experimental condition for the hydrodeoxygenation (HDO) of 3.5 g of OA was 370 °C, 20 mg of FPdOx/Zeol, and 100 mL/min of reducing gas (5% H₂/N₂) flow rate. The FTIR spectra of the evolved products at these conditions showed that the HDO of OA proceeded via the formation of stearic acid as intermediate product. A mixture of highly purified paraffinic fuel (iso-octadecane, ∼18%, and n-ocatadecane, ∼69%) was obtained after 44 min of HDO. The production of iso-octadecane which is an excellent fuel additive because of its antifreezing quality was due to the presence of fluoride ion in the FPdOx/Zeol. The FPdOx/Zeol demonstrated excellent qualities, and the results are promising toward further research and industrialization.