From Biomass‐Derived Furans to Aromatics with Ethanol over Zeolite

Abstract

We report a novel catalytic conversion of biomass-derived furans and alcohols to aromatics over zeolite catalysts. Aromatics are formed via Diels-Alder cycloaddition with ethylene, which is produced in situ from ethanol dehydration. The use of liquid ethanol instead of gaseous ethylene, as the source of dienophile in this one-pot synthesis, makes the aromatics production much simpler and renewable, circumventing the use of ethylene at high pressure. More importantly, both our experiments and theoretical studies demonstrate that the use of ethanol instead of ethylene, results in significantly higher rates and higher selectivity to aromatics, due to lower activation barriers over the solid acid sites. Synchrotron-diffraction experiments and proton-affinity calculations clearly suggest that a preferred protonation of ethanol over the furan is a key step facilitating the Diels-Alder and dehydration reactions in the acid sites of the zeolite.

Multi‐site Cooperativity in Alkali‐Metal‐Exchanged Faujasites for the Production of Biomass‐Derived Aromatics

“…The DACD reaction of 2‐methylfuran with ethylene over heterogeneous Lewis acid faujasites and homogeneous Lewis acid metal chloride catalysts has been studied by Wijaya et al . Dehydrative aromatization of the cycloadduct originating from the DAC reaction of furanic compounds with ethanol in the presence of Brønsted acidic zeolite catalysts was studied by Tsang et al . and Zhao et al .…”

“…An alternative route to TPA by directly using biomass-derived oxygenated furanici ntermediates in aD ACD reactioni st herefore more appealing and potentially more atom-efficient. [32] In recent years,m anye xperimental [33][34][35][36][37][38][39][40][41][42][43] and theoretical [44][45][46] studies have been devoted to the DACD conversion of furanic compounds and alkenes to aromatics over different heterogeneous catalysts. Mosts tudies focusedo nt he DACD reactiono f 2,5-DMF with ethylene to produce para-xylene.…”

Hydrogenolysis of Biomass‐Derived 5‐Hydroxymethylfurfural to Produce 2,5‐Dimethylfuran Over Ru‐ZrO2‐MCM‐41 Catalyst

“…Among the foregoing products, 2,5‐dimethylfuran (DMF) is considered to be an important transportation fluid because of its high octane number (RON=119), greater energy density (30 kJ cm −3 ), ultimate boiling point (92‐94 °C), lower oxygen content (O/C=0.17) and calorific value (34 MJ kg −1 ) composed with a poor water solubility (2.3 g L −1 ). Moreover, transformation of DMF into valuable benzene‐based chemicals (e. g., p‐xylene) via Diels‐Alder reactions is also reported …”

Differential Adsorption of l‐ and d‐Lysine on Achiral MFI Zeolites as Determined by Synchrotron X‐Ray Powder Diffraction and Thermogravimetric Analysis

“…To study the Lys-framework interactions at the atomistic resolution, the closest interatomic distance between the acarboxylate and a-amino groups with the framework Oatoms were analysed. Note that as Ha toms cannot be directly located by this technique,t he rigid framework Oa toms are chosen as the crystallographic pointers in measuring the interatomic distances to represent the actual chemical acidbase information, that is,O framework ÀH···O Lys .T he interatomic distances are comparable to those in our previous reports on the study other adsorbate molecules (namely,m ethanol, [10,11] ammonia, [12] pyridine, [13] and furans [20][21][22] )onH-ZSM-5 and H-USY zeolites.I ts uggests the formation of acid-base adducts between Lysa nd BASs.A ss een in Figure 3, when l-a nd d-Lysa re pre-adsorbed on H-ZSM-5(46) at pH 2.2, the closest interatomic distances observed at Site Iare,for l-Lys:O9 LysI À O18 framework = 2.47(3) and N10 LysI ÀO15 framework = 3.03(3) , and for d-Lys:O 9 LysI ÀO18 framework = 3.02(3) and N10 LysI À O21 framework = 2.74(3) .T he crystallographic O21 framework site is located on the opposite side of the 10-membered ring with respect to O15 framework .W hereas,f or Site II, the closest interatomic distances observed are for l-Lys:O 8 LysII À O7 framework = 2.42(3) and N10 LysII ÀO1 framework = 3.69(3) and for d-Lys:O 8 LysII ÀO7 framework = 2.40(3) and N10 LysII À O5 framework = 3.37(3) .T he closest interatomic distances for l-a nd d-Lys pre-adsorbed on H-ZSM-5 at pH 1.0 are comparable to those pre-adsorbed at pH 2.2. Ther efined adsorbate structures are verified with our DFT calculations (Figure 4).…”