Upgrading of lignocellulosic biomass-derived furfural: An efficient approach for the synthesis of bio-fuel intermediates over γ-alumina supported sodium aluminate

Abstract

• A simple and green protocol for the aldol condensation of furfural with acetone was developed over γ-Al 2 O 3 supported sodium aluminate (SA) catalyst. • The SA/γ-Al 2 O 3 catalyst demonstrated the unprecedented catalytic activity (99.5% conversion with 90% selectivity) under mild conditions. • The distribution of active sites over the high surface area, amount of basic sites, and inherent mesoporosity are the contributing factors. • SA/γ-Al 2 O 3 surpassed the activity of state of the art materials reported for this transformation. • The correlation between catalyst properties and the catalytic activity was studied. The synthesis of value-added chemicals from simple molecules originating from biomass have been greatly acknowledged today. Herein, we report a sustainable protocol for the furfural (FUR) condensation with acetone (Ac) over γ-Al 2 O 3 supported sodium aluminate (SA) catalyst. The SA/γ-Al 2 O 3 catalysts are characterized with different techniques like TPD, XRD, TGA, BET, SEM, and FTIR analysis. The effect of SA loading, catalyst concentration, mole ratio, reaction time, and the reaction temperature on product distribution were investigated systematically. The 25wt.% SA/γ-Al 2 O 3 demonstrated the unprecedented conversion of FUR (99.5%) with 90% selectivity to 4-(2-Furyl)-3-buten-2-one (FAc) under mild reaction conditions. The catalyst surpassed the activity of state of the art materials reported for this transformation. The textural properties of SA/γ-Al 2 O 3 are in good correlation with the observed catalytic activity of the material. The significant catalytic activity is attributed to its inherent properties such as the active sites distribution over high specific surface area (SSA), amount of basic sites, and inherent mesoporosity. The catalytic activity of the 25SA/γ-Al 2 O 3 is compared with the various catalysts reported and is superior to the reported catalysts. On top of it, recycling experiments have proven that the catalyst is stable that can be used repeatedly with consistent catalytic activity.