Transesterification of Azadirachta indica seed oil into biodiesel using MgO-supported tri-metallic catalyst– synthesis and characteristic evaluation

Environmentally sustainable biodiesel from non-edible waste Azadirachta indica (neem) seed oil provides an economical alternative to combat issues caused by fossil fuel combustion. The current study reports specifically a bi-functional trimetallic (Ca-Sr-Mo) catalyst delineated across MgO support synthesized via wet impregnation and green synthesis route using Cassia fistula extract. In FTIR analysis, peaks appeared at 992, 1390, 1424 cm−1 represent the C–O stretching, C–H deforming and M–O–M bending deformation vibrations, respectively. The diffraction peaks of all CaO, SrO, MoO2, and MgO in the XRD pattern represent the formation of catalysts. The prepared catalyst is employed in the transesterification reaction to convert A. indica oil into fatty acid methyl ester. The study used the response surface methodology to examine factors that could affect the conversion rate, including oil-methanol molar ratio, reaction time, and catalyst loading. The results were analyzed to determine the best combination of factors that yields the optimal catalytic transesterification process. The highest yield of 89.92 % was achieved under optimum conditions of methanol-to-oil (18:1), catalyst loading (5 wt%), and time (6 h). In FTIR analysis, the new peak appeared at 1160 cm−1, indicating the formation of methyl esters, while 1H NMR analysis confirmed the successful conversion of A.indica oil into FAMEs by the appearance of strong singlet at 3.66 ppm for methoxy proton.1H NMR also indicated a high yield (90.09 %) which is comparable to RSM obtained yield. Additionally, a reaction mechanism has been proposed. Specifically, GC-MS FAME profiles and physicochemical testing confirmed that biodiesel meets ASTMD6751 and EN14214 standards with key fatty acid methyl esters and desirable properties. [Display omitted] ✓Tri-metallic constructs were prepared and fully characterized.✓Catalytic transesterification of Azadirachta indica seed oil into biodiesel.✓Biodiesel, as a low-emissions diesel, is a noteworthy supernumerary fuel.✓The 90.09 % yield was achieved under optimum conditions of methanol-oil (18:1).