Value-Added Bio-Chemicals Commodities from Catalytic Conversion of Biomass Derived Furan-Compounds

Synthesis rifaximin with copper (Rif-Cu) and copper oxide (Rif-CuO) nanoparticles Considerable dye decolorization: An application of aerobic oxidation of eco-friendly sustainable approach

In this study, rifaximin with copper (Cu) and copper oxide (CuO) nanoparticles (NPs) were synthesised. The resultant CuO nanoparticles were used to degrade Rhodamine B (RhB) and Coomassie Brilliant Blue (G250). Rifaximin copper and copper oxide nanoparticles were characterised using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), and gas chromatography-electrochemical mass spectrometry (GC-EI-MS). An FT-IR study confirmed the formation of Cu in the 562 cm-1 peak range. Rifaximin Cu and CuO Nanoparticles displayed UV absorption peaks at 253 nm and 230 nm, respectively. Coomassie Brilliant Blue G250 was completely decolourised in Cu nanoparticles at 100 %, and Rhodamine B was also decolourised in Rifaximin CuO nanoparticles at 73 %, although Coomassie Brilliant Blue G250 Rifaximin Cu nanoparticles absorbed a high percentage of dye decolorization. The aerobic oxidation of isopropanol conversion was confirmed by GC-MS analysis. Retention time of 27.35 and 30.32 was confirmed using Cu and CuO nanoparticles as the final products of 2-propanone. It is used in the textile and pharmaceutical industries for aerobic alcohol oxidation. Rifaximin CuO nanoparticles highly active in aerobic oxidation. The novelty of this study is that, for the first time, rifaximin was used for the synthesis of copper and copper oxide nanoparticles, and it successfully achieved decolorization and aerobic oxidation.

Catalytic Routes to Produce Polyphenolic Esters (PEs) from Biomass Feedstocks

Polyphenolic esters (PEs) are valuable chemical compounds that display a wide spectrum of activities (e.g., anti-oxidative effects). As a result, their production through catalytic routes is an attractive field of research. The present review aims to discuss recent studies from the literature regarding the catalytic production of PEs from biomass feedstocks, namely, naturally occurred polyphenolic compounds. Several synthetic approaches are reported in the literature, mainly bio-catalysis and to a lesser extent acid catalysis. Immobilized lipases (e.g., Novozym 435) are the preferred enzymes thanks to their high reactivity, selectivity and reusability. Acid catalysis is principally investigated for the esterification of polyphenolic acids with fatty alcohols and/or glycerol, using both homogeneous (p-toluensulfonic acid, sulfonic acid and ionic liquids) and heterogeneous (strongly acidic cation exchange resins) catalysts. Based on the reviewed publications, we propose some suggestions to improve the synthesis of PEs with the aim of increasing the greenness of the overall production process. In fact, much more attention should be paid to the use of new and efficient acid catalysts and their reuse for multiple reaction cycles.

High-throughput monitoring of biomass conversion reaction with automatic time-resolved analysis

Reactions of biomass conversions are of great importance in fine chemistry for substantial development. While numerous studies have been performed to search for functional materials to catalyze biomass conversions, a robust and high-throughput analytical method is rather limited, which may hamper further integration and automation of the reactions. Here we propose an automatic and sequential method for the investigation of glucose conversion. By combining sequential sample injection and high-speed capillary electrophoresis (HSCE) techniques, we can monitor the glucose conversion from the beginning toward the end with a good temporal resolution. The HSCE assays are performed using short capillaries (effective length of 10 cm, i.d./o.d. of 50 μm/365 μm), and the analytes are separated at an electric field of 467 V/cm and are detected by UV-absorption at 200 nm with mixed 0.2 mM CTAB, 10 mM borate, 20 mM sorbic acid (pH 12.2) as the background electrolyte. All compounds involved in the reaction, including all products (fructose, 5-hydroxymethylfurfural, formic acid and levulinic acid) and the remaining substrate glucose, are efficiently separated and simultaneously detected from just one analysis with a temporal resolution of one minute. The method exhibits high-resolution separation, a wide linear range with limit-of-detection down to μg/mL-level, as well as excellent repeatability in sequential analysis. It is indicated that the proposed method is of great value in the analysis of complicated biomass conversion and could be potentially applied in various catalytic chemical reactions.

Ruthenium Nanoparticles Intercalated in Montmorillonite (nano-Ru@MMT) Is Highly Efficient Catalyst for the Selective Hydrogenation of 2-Furaldehyde in Benign Aqueous Medium

Chemoselective hydrogenation of 2-furaldehyde to furfuryl alcohol using green solvents is an important research area to get eco-friendly fuels and fine chemicals. Herein, we report ruthenium nanoparticles (~1.8 nm) intercalated in montmorillonite as an efficient catalytic system, which can selectively hydrogenate 2-furaldehyde in a benign aqueous medium. The complete conversion was observed at 40 °C with 1 MPa H2, the selectivity of furfuryl alcohol being >99%, and turnover number 1165. After a catalytic run, the montmorillonite-supported ruthenium nanoparticles can be recycled and reused without losing their activity and selectivity.