Biodiesel production from rapeseed oil and methanol via transesterification reaction facilitated by various monometallic catalyst supported on natural zeolite (NZ) was investigated. The physicochemical characteristics of the synthesized catalysts were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), temperature-programmed-reduction in hydrogen (H2-TPR), temperature-programmed-desorption of ammonia (NH3-TPD), Scanning Electron Microscope equipped with EDX detector (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) methods. The highest activity and methyl ester yields were obtained for the Pt/NZ catalyst. This catalyst showed the highest triglycerides conversion of 98.9% and fatty acids methyl esters yields of 94.6%. The activity results also confirmed the high activity of the carrier material (NZ) itself in the investigated reaction. Support material exhibited 90.5% of TG conversion and the Fatty Acid Methyl Esters yield (FAME) of 67.2%. Introduction of noble metals improves the TG conversion and FAME yield values. Increasing of the metal loading from 0.5 to 2 wt.% improves the reactivity properties of the investigated catalysts.

This work provides valuable information about unexplored catalytic systems tested in the transesterification reaction of vegetable oil with methanol. It was demonstrated that natural zeolite treatment leads to enhanced catalytic activity and yield of biodiesel production. The activation of the catalytic material in a mixture of 5% H2–95% Ar resulted in an improvement of the values of the TG conversion and fatty acid methyl esters (FAME) yield. In addition, it was proven that the incorporation of CaO, MgO and SrO oxides onto the natural zeolite surface improves the TG conversion and FAME yield values in the transesterification reaction.

This work presents the comparative physicochemical and catalytic studies of metal oxide MgO catalysts in a transesterification reaction. The influence of the Si/Al ratio in the catalytic material on their catalytic properties in the studied process was extensively evaluated. In addition, the effect of the type of zeolite ZSM-5 form on the catalytic reactivity of MgO based catalysts was investigated. In order to achieve the main goals of this work, a series of MgO/ZSM-5 catalysts were prepared via the impregnation method. Their physicochemical properties were studied using X-ray diffraction (XRD), BET, FTIR and TPD-CO2 methods. The highest activity in the studied process exhibited MgO catalyst supported on ZSM-5 characterized by the highest ratio between silica and alumina. The most active catalyst system in the transesterification reaction was 10% MgO/ZSM-5 (Si/Al = 280), which showed the highest value of higher fatty acid methyl esters (94.6%) and high yield of triglyceride conversion (92.9%). The high activity of this system is explained by the alkalinity, sorption properties in relation to methanol and its high specific surface area compared to the rest of the investigated MgO based catalysts.

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