A comparative study on physicochemical properties of two nanomagnetic compounds CaO@Fe 3 O 4 and Fe 3 O 4 @CaO and their catalytic role on biodiesel preparation

• Published in: Environmental progress & sustainable energy 2020-07, Vol.39 (4)
• Main Authors: Mardani, Hamid Reza, Forouzani, Mehdi, Moradi, Nazanin, Kheibarian, Zahra
• Format: Article
• Language: English
• ISSN: 1944-7442; 1944-7450
• DOI: 10.1002/ep.13395

In this study, two nanomagnetic compounds from calcium oxide and iron (II, III) oxide (CaO@ Fe 3 O 4 and Fe 3 O 4 @CaO) were synthesized by hydrothermal method and were characterized by general techniques such as Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy , energy dispersive spectroscopy, MAP, and Brunauer–Emmett–Teller. The chemical and physical properties of these nanocompounds were studied, and they were compared with each other. The type of metal oxide as a support part was considered to be very interesting in this research. By changing the support from Fe 3 O 4 to CaO: (a) the crystal size decreased from 41.60 to 36.82 nm, (b) the morphology was significantly changed, CaO@ Fe 3 O 4 got a misty mountain‐like shape but other compound got a tiny spherical shape, (c) surface area and pore volume decreased as CaO@Fe 3 O 4 is macroporous and the other compound is microporous. (d) Fe 3 O 4 as support yielded better results than CaO due to more amount of coating. Both nanomagnetic compounds efficiently performed transesterification process using sunflower oil and methanol without any additional base compounds but CaO@Fe 3 O 4 is slightly stronger catalyst than Fe 3 O 4 @CaO. Prepared biodiesel was characterized by nuclear magnetic resonance ( 1 H NMR), 13 C‐NMR, and gas chromatography apparatuses. These results also corresponded with the prepared biodiesel by NaOH as a standard.