Fructose Transformations in Ethanol using Carbon Supported Polyoxometalate Acidic Solids for 5-Ethoxymethylfurfural Production

Ethanolysis of selected catalysis by functionalized acidic ionic liquids: an unexpected effect of ILs structural functionalization on selectivity phenomena

Functionalization of acidic imidazolium ILs (addition of OH groups, deactivation of C2–H proton) changes the selectivity of the carbohydrate ethanolysis reaction.

Catalytic Synthesis of the Biofuel 5-Ethoxymethylfurfural (EMF) from Biomass Sugars

A new generation of bioplatform molecule 5-ethoxymethylfurfural (EMF) has excellent energy density and combustion performance, which makes it a potential fuel additive. This article reviews the factors that affect the production of EMF from different feedstocks, including platform compounds, monosaccharides, polysaccharides, and raw lignocellulosic biomass. Focus is placed on discussing the catalytic efficiency with pros and cons of different acid catalysts, including homogeneous catalysts (i.e., liquid acids and metal salts), heterogeneous catalysts (i.e., zeolites, heteropolyacid-based hybrids, and SO3H-based catalysts), ionic liquids, mixed acid catalysts, and deep eutectic solvents (DESs). Except for the commonly used ethanol solvent, this review also summarizes the influence of the cosolvent system (e.g., ethanol/dimethylsulfoxide (DMSO), ethanol/tetrahydrofuran (THF), and ethanol/γ-valerolactone (GVL)) on the EMF yield.

Comparative Study of Different Acidic Surface Structures in Solid Catalysts Applied for the Isobutene Dimerization Reaction

Dimerization of isobutene (IBE) to C_8s olefins was evaluated over a range of solid acid catalysts of diverse nature, in a fixed bed reactor working in a continuous mode. All catalytic materials were studied in the title reaction performed between 50–250 °C, being the reaction feed a mixture of IBE/helium (4:1 molar ratio). In all materials, both conversion and selectivity increased with increasing reaction temperature and at 180 °C the best performance was recorded. Herein, we used thermogravimetry analysis (TGA) and temperature programmed desorption of adsorbed ammonia (NH₃-TPD) for catalysts characterization. We place emphasis on the nature of acid sites that affect the catalytic performance. High selectivity to C_8s was achieved with all catalysts. Nicely, the catalyst with higher loading of Brønsted sites displayed brilliant catalytic performance in the course of the reaction (high IBE conversion). However, optimum selectivity towards C₈ compounds led to low catalyst stability, this being attributed to the combined effect between the nature of acidic sites and structural characteristics of the catalytic materials used. Therefore, this study would foment more research in the optimization of the activity and the selectivity for IBE dimerization reactions.