Liquid phase alkylation of benzene with dec-1-ene catalyzed on supported 12-tungstophosphoric acid

3-Bromopyridine-Heterogenized Phosphotungstic Acid for Efficient Trimerization of Biomass-Derived 5-Hydroxymethylfurfural with 2-Methylfuran to C21 Fuel Precursor

The production of long-chain carbon compounds (C9-C21) from biomass derivatives to alternate traditional fossil diesel is sustainable, eco-friendly, and potentially economic for modern industry. In this work, phosphotungstic acid heterogenized by 3-bromopyridine was achieved using a solvothermal method, which was demonstrated to be efficient for trimerization of biomass-derived 5-hydroxymethylfurfural (HMF) with 2-methylfuran (2-MF) to C21 fuel precursor (57.1% yield) under mild reaction conditions. The heterogeneous acidic catalyst could be reused for four consecutive cycles without obvious loss of activity, and different characterization techniques (e.g., XRD (X-ray diffraction), TG (thermogravimetric analysis), SEM (scanning electron microscope), FT-IR (Fourier transform infrared spectroscopy), and BET (Brunauer-Emmet-Teller)) were utilized to investigate the performance of the catalyst. In addition, a plausible reaction pathway was postulated, on the basis of results obtained by NMR (nuclear magnetic resonance) and GC-MS (gas chromatography-mass spectrometer). This strategy provides a facile and efficient approach to prepare a recyclable acidic catalyst for the production of diesel fuel precursor from biomass via controllable polymerization.

Phosphotungstic acid heterogenized by assembly with pyridines for efficient catalytic conversion of fructose to methyl levulinate

Solid acid-catalyzed sugar degradation has been considered to be an efficient approach to synthesize alkyl levulinates (which can be used as fuel additives and surfactants). However, those catalytic processes typically involve harsh reaction conditions and high cost for catalyst preparation. We prepared a series of phosphotungstic acid organic hybrids by a simple solvothermal method, and used them as heterogeneous catalysts for the selective degradation of fructose to methyl levulinate (ML) in methanol with high efficiency under mild reaction conditions. The catalysts were characterized systematically, and the effects of different substituents in pyridine, reaction temperature/time, catalyst dose, and fructose concentration studied. The 3-FPYPW hybrid prepared from 3-fluoropyridine and phosphotungstic acid exhibited superior catalytic activity for the synthesis of ML (82.5%) from fructose (97.8%). A possible reaction pathway was proposed. In addition, the catalyst could be separated from the reaction mixture readily, and reused without remarkable loss of reactivity.

A high yield of methyl levulinate (82.5%) was achieved from fructose via a one-pot multi-step conversion process using acidic 3-FPYPW as a heterogeneous catalyst.

Comparative study of three heteropolyacids supported on carbon materials as catalysts for ethylene production from bioethanol

The efficacy of three different heteropolyacids (HPAs) supported on activated carbon (AC) or on high surface area graphite (HSAG), has been comparatively evaluated in the dehydration of bio-ethanol to yield ethylene or diethyl ether.