Single‐Pot Alcoholysis of Furfuryl Alcohol to Alkyl Levulinates Using Heterogenized p‐TSA Catalyst

• Published in: ChemistrySelect (Weinheim) 2021-07, Vol.6 (26), p.6636-6643
• Main Authors: Patil, Chetana R., Kamble, Sanjay P., Rode, Chandrashekhar V.
• Format: Article
• Language: English
• Subjects: Biomass; Ethyl levulinate; Fuel additive; Furfuryl alcohol; Heterogeneous catalysis
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202101392

Synthesis of levulinate esters which are known to be excellent sustainable fuel additives, was achieved by alcoholysis of furfuryl alcohol over strong solid acid catalyst, prepared by copolymerization of p‐toluenesulfonic acid with paraformaldehyde. Our catalyst possessed Brønsted acidity (3 mmol/g) with an excellent stability up to 220 °C. XPS, FT‐IR and Pyridine‐IR along with microanalysis studies confirmed the presence of terminal −SO3H functional groups responsible for Brønsted acidity in the catalyst. The catalyst was found to efficiently catalyze the alcoholysis of furfuryl alcohol to give alkyl levulinates under mild reaction conditions. The complete conversion of furfuryl alcohol with 96 % and 97 % selectivities to ethyl and butyl levulinates could be achieved using ethanol and butanol, respectively. Detailed study on effect of various reaction parameters like catalyst loading, reaction time and reaction temperature on conversion and product distribution was also carried out for the ethanolysis of furfuryl alcohol to ethyl levulinate. The catalyst could be easily recovered and recycled for five times successfully, with no loss in its original activity. p‐TSA‐PFD catalyst possesses Brønsted acidity and showed superior activity for the alcoholysis of furfuryl alcohol with its complete conversion forms ethyl levulinate (EL) and butyl levulinate (BL) with 96 % and 97 % selectivity, respectively. EL and BL both are well‐known second‐generation biofuels. Presence of terminal −SO3H functional groups responsible for Brønsted acidity in the catalyst. Successful heterogenization of p‐TSA (p‐toluenesulfonic acid) lead to its higher efficiency and stability.