Ionic Liquid‐Encapsulated Zeolite Catalysts for the Conversion of Glucose to 5‐Hydroxymethylfurfural

Abstract

Ionic Liquid (1‐Butyl‐3‐methylimidazolium Bromide ([BMIM]Br) or Choline Chloride (ChCl)) encapsulated zeolites (HY and H‐MOR) have been synthesized by ship‐in‐a‐bottle strategy and tested for selective conversion of glucose to 5‐Hydroxymethylfurfural (HMF). Nitrogen sorption analysis showed that the surface area and total pore volume decreased and average pore size increased significantly when the zeolites are encapsulated with ionic liquids. The major effect was found to be on the microporosity whereas the mesoporosity is affected only marginally. From Thermogravimetric Analysis it is observed that the decomposition temperature of ionic liquids increased when encapsulated in the zeolite. The catalytic tests were carried out in presence of NaCl and an extraction phase to remove the formed HMF. The test results of BMIMBr−H‐MOR indicate that even though there is a significant decrease in the surface area with encapsulation, the yield and selectivity are higher with this catalyst as compared to its bare zeolite counterpart. The effect of the addition of NaCl and extraction phase and reaction conditions such as reaction time and temperature on activity and yield of HMF are evaluated on the best catalyst. In catalyst stability study, the reasons for deactivation of catalyst are identified by post‐reaction catalyst characterizations.

Zeolite Supported Ionic Liquid Catalysts for the Hydrochlorination of Acetylene

“…The surface area of CaX had reduced from 343 to 28 m 2 /g, upon anchoring the thin ionic liquid film. The decreases in the BET surface areas of IL/CaX were attributed to the immobilization of ionic liquid on porous CaX, resulting in the block of micropores and decrease of surface areas [27]. The structural properties of the supported ionic liquid on zeolite agreed with the reported values in Reference [28].…”

“…However, the relative intensity of (111) peak was lower than that of CaX. This could be attributed to the disordering of the porous structure and variation the electron density (especially for the major peak at 2θ = 6.1 • ), due to immobilization of an ionic liquid layer onto zeolite [27,28]. These results agreed well with the SEM analyses.…”

Novel One‐Step Process for the Production of Levulinic Acid from Furfural over Hierarchical Zeolites in a Microwave Reactor

“…Further, in our previous works, we explored the routes for the production of LA/HMF from the biomass, cellulose, or C6 sugars using stable hierarchical/functionalized zeolite catalysts. [ 34–38 ] The integration of the process reported in the present study with our previously reported C6 routes for LA production allows the complete utilization of the C5 and C6 parts of the lignocellulosic biomass.…”

Recent advances in the synthesis and applications of mordenite zeolite – review

“…U.S. Energy Department recognized levulinic acid among the platform chemicals. 144 Several heterogeneous catalysts such as HZSM-5, 145 HY zeolite, 146 ionic liquid encapsulated zeolites, 147 Sn-beta, 148 Amberlyst 70, 149 SAC13, ZrO 2 , 150 and niobium oxides 151 have been examined towards the conversion of cellulose to levulinic acid. But, these catalysts are suffering from a few drawbacks for instance low yields, low conversion, 152 reaction times are longer, 153 need of costly and harmful solvents, as well as deactivation caused by the formation of humins.…”