Study on transition metal ion Fe~(3+) catalyzed biodiesel oxidation and inhibition mechanism

摘要

Methyl linoleate is used as an alternative component of biodiesel. The catalytic oxidation of biodiesel is studied in the presence of iron acetate using methyl linoleate as the alternative component. The composition of the products obtained from the oxidation process of methyl linoleate is analyzed by GC-MS and liquid phase microextraction. Density functional theory is used to calculate the electronic effects of the related reactants and products and the related catalytic oxidation reaction paths are derived. The results show that during the process of catalytic oxidation of methyl linoleate in biodiesel, mainly the catalytic cracking reaction of C-H and C-C bonds and Fenton-like reaction occur. The combination of two antioxidants, TEPA and [MI][C6H2(OH)3COO], can effectively inhibit the catalytic oxidation of Cu2+ and Fe3+ and interrupt the chain reaction of the oxidation process. The negative value of the electrostatic potential of ferric acetate is relatively large, it is obviously alkaline, and has a certain ability to bind with H. The irregular structure of the iron acetate unit cell makes the O-Fe bond in the molecule easy to break, which is beneficial for the catalytic oxidation process.