Investigation into the shape selectivity of zeolite catalysts for biomass conversion

Jae, Jungho; Tompsett, Geoffrey A.; Foster, Andrew J.; Hammond, Karl D.; Auerbach, Scott M.; Lobo, Raúl F.; Huber, George W.

doi:10.1016/j.jcat.2011.01.019

Cited by 996 publications

(619 citation statements)

References 84 publications

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“…The CM0 rejected (100%) all the organic substances tested except water. As the kinetic diameter of water is 0.26 nm and the diameters of sucrose and glucose are 0.86 nm [49] and 0.9 nm [50], these results strongly suggest that the CM0 membranes have pores well below 0.86 nm. All membranes exposed to vacuum could not reject glucose and sucrose, thus giving a clear indication that pore sizes of CM30 to CM1200 membranes have increased well above 0.9 nm.…”

Section: Membrane Characterisation and Testingmentioning

confidence: 83%

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Jalil

Wang²,

Yacou

et al. 2017

Journal of Membrane Science

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This work shows the preparation and separation performance assessment of carbon membranes derived from phenolic resin by a vacuum-assisted method and carbonisation in an inert atmosphere.The vacuum time played an important role in tailoring the structure of the membranes. For instance, pore volumes and surface areas increased from 0.81 and 834 to 2.2 cm 3 g -1 and 1910 m 2 g -1 , respectively, as the vacuum time exposure increased from 0 to 1200 s. The significant structural changes correlated very well with water permeation, as fluxes increased by 91% as the vacuum time increased from 0 to 1200s, reaching up to 169 kg m -2 h -1 at 5 bar. Molecular weight cut-off tests showed no rejection for the smaller glucose and sucrose molecules, though this increased to ~ 80% and full rejection for 36kD and 400kD polyvinyl pyrrolidine. Interestingly, FTIR spectra showed that the peaks of C-H stretching vibration (2800-3200 cm -1 ) and C-O stretching (1030 cm -1 ) became more pronounced as a function of increasing vacuum time, strongly suggesting that the use of vacuum further assisted in the polycondensation of phenolic oligomers. Based on these outcomes, a cluster to cluster model is proposed, whereby vacuum application promoted crosslinking reactions of the phenolic resin, creating microporous regions within the clusters, and mesoporous regions between the clusters. 2 Graphical AbstractKeywords: carbon membranes; vacuum-assisted method; water; molecular weight cut-off.

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Section: Membrane Characterisation and Testingmentioning

confidence: 83%

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Jalil

Wang²,

Yacou

et al. 2017

Journal of Membrane Science

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“…66 Indeed, this type of chiral -lactones can be achieved from levoglucosenone (LGO), which is a very interesting dehydrated sugar presenting two chiral and six different functional carbon atoms (see Figure 12), and it can be obtained in high yields from acid-catalyzed pyrolysis processes. 67 The selective oxidation of LGO to the intermediate formate lactone (FBO, see Figure 12) occurs through a Baeyer-Villiger reaction, and the former reported catalysts to undergo the oxidation processes were homogeneous organic peracids, such as peracetic acid or m-chloroperbenzoic acid. 68 At this point, Paris et al introduced water resistant Lewis acid zeolites as catalysts (SnBeta and Zr-Beta) and hydrogen peroxide as oxidant agent for the green production of HBO in a one-pot process.…”

Section: 7-synthesis Of Optically Pure -Lactones From Pyrolysis Pmentioning

confidence: 99%

State of the art of Lewis acid-containing zeolites: lessons from fine chemistry to new biomass transformation processes

2014

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“…Thus, this suggests that using this approximation for determining the kinetic diameter of oxygenates is reasonable. 10 The results from this table suggests that all compounds can freely diffuse in the pores of the Sn-β, Sn-MCM-41 and Sn-SBA-15 catalysts. In Sn-MFI however, DHA and MLA can diffuse freely, whereas the kinetic diameter of the more bulky ERU, MVG and MMHB exceed or are equal to the maximum of the pore size range.…”

mentioning

confidence: 94%

Confinement Effects in Lewis Acid-Catalyzed Sugar Conversion: Steering Toward Functional Polyester Building Blocks

et al. 2015

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We report the use of solid Lewis acid catalysts for the conversion of tetrose sugars to four-carbon α-hydroxy acid esters (C4-AHA), which are useful as functional polyester building blocks. Sn-β was by far the most active and selective catalyst, yielding up to 80% methyl vinyl glycolate (MVG), methyl-4-methoxy-2-hydroxybutanoate (MMHB), and α-hydroxy-γ-butyrolactone (HBL) combined at 95% conversion. A very high turnover frequency (TOF) of 330 molC4‑AHA molSn h–1 was attained using Sn-β, a more than 6-fold increase compared with homogeneous SnCl4·5H2O. It is shown that, using different Sn-based catalysts with various pore sizes, the product distribution is strongly dependent on the size of the catalyst pores. Catalysts containing mainly mesopores, such as Sn-MCM-41 or Sn-SBA-15, prefer the production of the more bulky MMHB, whereas microporous catalysts such as Sn-β or Sn-MFI favor the production of MVG. This effect can be further enhanced by increasing the reaction temperature. At 363 K, only 20% MVG is attained using Sn-β, but at 433 K, this increases to 50%. Using a kinetic analysis, it was found that, in microporous catalysts, steric hindrance near the Sn active site in the catalyst pores plays a dominant role in favoring the reaction pathway toward MVG. Moreover, the selectivity toward both products is kinetically controlled.

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Investigation into the shape selectivity of zeolite catalysts for biomass conversion

Cited by 996 publications

References 84 publications

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

State of the art of Lewis acid-containing zeolites: lessons from fine chemistry to new biomass transformation processes

Confinement Effects in Lewis Acid-Catalyzed Sugar Conversion: Steering Toward Functional Polyester Building Blocks

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