One-Pot Conversion of Furfural to Gamma-Valerolactone over Zr-SBA-15: Cooperation of Lewis and Brønsted Acidic Sites

Abstract

A series of bifunctional Zr-SBA-15_x of varying molar Si/ Zr ratio x (15−730) with isolated Lewis and Brønsted acid sites were prepared by an in situ synthesis procedure and applied to the one-pot conversion of furfural (FUR) to gamma-valerolactone (GVL). These catalysts were detailed and characterized by XRF, XRD, N 2 physisorption, FTIR, SEM, TEM, NH 3 -TPD, and pyridine-DRIFT techniques. On all these Zr-SBA-15_x catalysts, the conversion of FUR was higher than 99%, while the GVL selectivity first increased and then decreased with decreasing x. A Zr-SBA-15_25 was identified as the best-performing catalyst, offering a 93.3% selectivity of GVL under optimized reaction conditions. The effects of reaction temperature, time, and solvent on catalytic performance were also investigated. Correlating the catalyst performance with the Brønsted acid site (BAS)/Lewis acid site (LAS) ratio uncovers that the balance between the LAS and the BAS would be the key to the higher catalytic performance. The possible reaction mechanism for the cascade conversion of FUR to GVL was proposed. Moreover, basic (lutidine and pyridine) additives were added, respectively, to the reaction solution to investigate their effects on catalytic performance, which provide a piece of evidence in support of the cooperative LAS−BAS bifunctional catalytic mechanism.

Kinetic Analysis of Hydrogen Transfer Route from Hot-Compressed 2-Propanol to Diphenyl Ether over NiCo/C Catalyst

“…H 2 production from IPA has been confirmed as an IPA dehydrogenation reaction . Considering conventional studies using compressed H 2 as a hydrogen donor, in situ formed H 2 from IPA may contribute to hydrogenolysis of the feedstocks as proposed in previous literature. − The role of H 2 has been kinetically determined by altering the H 2 pressure, which generally gave positive values for the reaction order. , In contrast, reports considering direct hydrogen transfer from IPA to a feedstock via the catalyst can be found in which H 2 itself is not a hydrogen donor. − Paone et al assumed the adsorption of hydrogen atoms from IPA onto the catalyst surface, and the reaction between the adsorbed hydrogen atoms and DPE was kinetically analyzed. As a result, the simulation showed good agreement with the experimental results.…”

Regulation of Pt Loading on Co/Al2O3 Catalysts for Selective Hydrogenation and Hydrogenolysis of 5‐Hydroxymethylfurfural to 2,5‐Bis(hydroxymethyl)furan and 2,5‐Dimethylfuran

“…Newly, the thermochemical conversion of platform substances derived from lignocellulosic biomass such as furfural (FAL), 5-hydroxymethylfurfural (HMF), and levulinic acid (LA) though the hydrogenation and hydrogenolysis reactions under pressurized H 2 system have been widely investigated using heterogenous catalysts. [1][2][3][4][5][6][7] Among the platform substances, the HMF derived from cellulose fraction via hydrolysis and dehydration processes could be utilized as a useful feedstock for the production of biofuels and biochemicals based on the modern biorefinery concept. In thermochemical routes under H 2 atmosphere, the valuable multipurpose compounds of 2,5-bis(hydroxymethyl)furan (BHMF) 2,5-dimethyltetrahydrofuran (DMTHF) 5-methylfurfuryl alcohol (MFA), 5-methylfurfural (MF), and 2,5-dimethylfuran (DMF) could be generated from the hydrogenation of C=O bond and hydrogenolysis of CÀ OH bond of HMF using heterogenous non-noble and noble catalysts.…”

“…Newly, the thermochemical conversion of platform substances derived from lignocellulosic biomass such as furfural (FAL), 5‐hydroxymethylfurfural (HMF), and levulinic acid (LA) though the hydrogenation and hydrogenolysis reactions under pressurized H 2 system have been widely investigated using heterogenous catalysts [1–7] . Among the platform substances, the HMF derived from cellulose fraction via hydrolysis and dehydration processes could be utilized as a useful feedstock for the production of biofuels and biochemicals based on the modern biorefinery concept.…”

Promoter Effect of Pt on Zr Catalysts to Increase the Conversion of Furfural to γ-Valerolactone Using Batch and Continuous Flow Reactors: Influence of the Way of the Incorporation of the Pt Sites

“…The transformation of FF into GVL involves cascade reactions with different intermediates that require the mediation of a catalyst to direct the process toward the selective one-step production of GVL . The use of different metals supported in different types of materials has been used as heterogeneous catalysts to produce GVL from FF in one step. − Among them, zirconia has been the most studied metal oxide due to the high yields of GVL obtained through consecutive reactions. − Zr species, which provide Lewis acid sites (LAS), have been typically deposited or incorporated on zeolite frameworks. Zeolites are known to provide Brønsted acid sites (BAS).…”

“… 29 − 32 Among them, zirconia has been the most studied metal oxide due to the high yields of GVL obtained through consecutive reactions. 33 − 35 Zr species, which provide Lewis acid sites (LAS), have been typically deposited or incorporated on zeolite frameworks. Zeolites are known to provide Brønsted acid sites (BAS).…”