Production of renewable oleo-furan surfactants by cross-ketonization of biomass-derived furoic acid and fatty acids

Abstract

Synthesis of 2-dodecanoyl furan is a crucial step in the formulation of oleo-furan sulfonates as bio-surfactants from biomass-derived furans and vegetable-oil-derived molecules. Herein, cross-ketonization of 2-furoic acid and lauric acid is proposed to produce the bio-surfactant precursor. Among the commonly reported metal oxide ketonization catalysts, the inexpensive and abundant iron oxides are demonstrated as effective and recyclable catalysts, enabling up to 77% selectivity to 2-dodecanoyl furan at 56% lauric acid conversion. Catalyst characterization by X-ray diffraction, H₂ temperature-programmed reduction, and X-ray photoelectron spectroscopy indicates that Fe₃O₄ is the catalytically active and stable phase. ¹³C isotopic tracing experiments suggest that cross-ketonization on Fe₃O₄ proceeds via a β-keto acid intermediate.