One‐Pot Microwave Assisted Etherification of Fructose to Sustainable Liquid Fuel Over TiS₂ Catalyst

Abstract In this study, TiS 2 catalyst was synthesized, which was partially reduced at 500 °C, 600 °C, 700 °C, and 800 °C to generate the active sites which resulted in enhanced catalysts’ performance for transforming fructose to 5‐ethoxymethylfurfural (EMF). The partial reduction resulted in the formation of TiS 2‐x giving rise to Lewis acid centers. The Lewis centers interact with the polar protic solvent in the reaction medium, forming H + moieties which facilitated the dehydration of fructose. The catalysts TiS 2 , TiS 2 500, TiS 2 600, TiS 2 700, and TiS 2 800 showed acid strengths of 1.08, 1.44, 1.69, 1.27, and 1.36 mmol/g, respectively. The prepared catalysts were tested for successive dehydration of fructose and etherification of 5‐hydroxymethylfurfural (HMF) resulting in an efficient 63% EMF yield at 160 °C in 30 min. The relationship between S vacancies, acidity and activity of the catalyst is well established in the study. The activation energies (140–160 °C) for fructose dehydration and HMF etherification were 44.67 kJ/mol and 20.86 kJ/mol respectively, which were comparable to other Brønsted acid catalysts. Additionally, rate constants indicates that HMF etherification ( k 2 = 5.77 to 7.8 min −1 ) is faster than fructose dehydration ( k 1 = 2.93 to 5.6 min −1 ) reaction showcasing an ideal green chemical process by integrating bio‐renewable feedstock, catalyst, and green protic solvent.