Visible light assisted sulfonic acid-functionalized porphyrin comprising benzimidazolium moiety for photocatalytic transesterification of castor oil. (15th November 2021)

• Record Type: Journal Article
• Authors: Bhansali, Karan J.; Balinge, Kamlesh R.; Raut, Subodh U.; Deshmukh, Shubham A.; Senthil Kumar, M.; Ramesh Kumar, C.; Bhagat, Pundlik R.
• Is Part Of: Fuel. Volume 304(2021)
• Publication Date: 2021-11-15
• Subjects: Transesterification -- Porphyrin -- Visible light -- Heterogeneous photocatalyst -- Methyl ricinoleate -- Biodiesel; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.121490
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: (SAFPBM) as heterogeneous photocatalyst was synthesized and characterized. The transesterification of castor oil performed with was with methanol ethanol in presence of visible light irradiations (5W/9W/12W LED). Maximum yield of the methyl biodiesel achieved of 94% (18 h, 15 mg photocatalyst under visible light at ambient conditions). The heterogeneous photocatalyst (SAFPBM) was recycled up to 7 th cycle without declined its activity. The possible mechanism is through formation of H +, CH3 O* and RCOOH* on the surface of catalyst. Abstract: A novel sulfonic acid-functionalized porphyrin comprising benzimidazolium moiety (SAFPBM) was prepared using 1-(3-formyl-2-hydroxybenzyl)-3-(4-sulfobutyl) (3a), dihydro-1H-benzo[d] imidazole-3-ium(oxidosulfinyl)bis(I1-oxy) (7a) and pyrrole in stoichiometric proportions. The synthesized photocatalyst was confirmed by various characterizations and assessed as a potential photocatalyst for the conversion of castor oil to biodiesel component by reaction with alcohols in presence of visible light irradiations (5 W/9W/12 W LED). The photocatalyst with 0.70 Hammett acidity, achieved 94% methyl ricinoleate in 18 h using 15 mg under visible light at ambient temperature and 6:1 methanol: castor oil ratio. SAFPBM displayed admirable photocatalytic activity with recyclability for 7 runs, towards the transesterification of castor oil and other vegetable oils at room temperature. The formation of methyl recinoleate was confirmed by NMR, DEPT, HRMS, HPLC and successfully hydrogenated to methyl 12-hydroxyoctadecanoate using HCOOH as a hydrogen source. A plausible reaction mechanism for the formation of methyl ricinoleate is projected via formation of H +, CH3 O* and unstable tetrahedral intermediate on Photocatalytic surface.