Catalytic performance of boron and aluminium incorporated ZSM-5 zeolites for isomerization of styrene oxide to phenylacetaldehyde

Qiao, Qiwei; Wang, Rijie; Gou, Ming-Lei; Yang, Xiaojing

doi:10.1016/j.micromeso.2014.04.042

“…Catalytic evaluation of borosilicates or boronmodified aluminosilicates has been shown to increase time-on-stream stability for a variety of chemistries. [31,32,59,80,81,82] However, recent reports have highlighted the limitations of using time-onstream (TOS) as a metric of catalyst stability, specially when comparing materials with varying reactivity, [53,83,84] as is the case with the two classes of zeolites in this study. We therefore use total turnover numbers per reactive proton (TON) during catalyst lifetime as the stability criteria (Eq.…”

Section: Deconvoluting the Pore Systems Of Aluminum-containing Mww In Catalysismentioning

confidence: 99%

Dehydra-decyclization of 2-methyltetrahydrofuran to pentadienes on boron-containing zeolites

Kumar

¹

,

Liu

²

,

Xu

³

et al. 2020

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show abstract

“…Catalytic evaluation of borosilicates or boronmodified aluminosilicates has been shown to increase time-on-stream stability for a variety of chemistries. [31,32,59,80,81,82] However, recent reports have highlighted the limitations of using time-onstream (TOS) as a metric of catalyst stability, specially when comparing materials with varying reactivity, [53,83,84] as is the case with the two classes of zeolites in this study. We therefore use total turnover numbers per reactive proton (TON) during catalyst lifetime as the stability criteria (Eq.…”

Section: Deconvoluting the Pore Systems Of Aluminum-containing Mww In Catalysismentioning

confidence: 99%

Dehydra-Decyclization of 2-Methyltetrahydrofuran to Pentadienes on Boron-Containing Zeolites

Kumar¹,

Liu²,

Xu³

et al. 2020

Preprint

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Biomass-derived 2-methyltetrahydrofuran (2-MTHF) undergoes tandem ring-opening and dehydration (dehydra-decyclization) to linear pentadienes, namely 1,3-pentadiene and 1,4-pentadiene. It can also fragment to butenes and formaldehyde through a competing retro-Prins condensation pathway. Using detailed kinetic measurements of 2-MTHF dehydra-decyclization on zeolites with disparate acidities (boro- and alumino-silicates) and micropore environments (MFI, MWW, and BEA), weakly acidic borosilicates were shown to exhibit ca. 10-30% higher selectivity to dienes at about five-to-sixty times lower proton-normalized rates than aluminosilicates (453-573 K). Dehydra-decyclization site time yields (STYs) were invariant for aluminosilicates within the investigated frameworks, indicating the absence of pore-confinement influence. However, individual site-normalized reaction rates varied by almost an order of magnitude on borosilicates in the order MWW > MFI > BEA at a given temperature (523 K), indicating the different nature of active sites in these weak solid acids. The diene distribution remained far from equilibrium and was tuned towards the desirable conjugated diene (1,3-pentadiene) by facile isomerization of 1,4-pentadiene. This tuning capability was facilitated by high bed residence times, as well as the smaller micropore sizes among the considered zeolite frameworks. The suppression of competing pathways and promotion of 1,4-pentadiene isomerization events lead to a hitherto unreported ∼86% 1,3-pentadiene yield and an overall ∼ 89% combined linear C5 dienes’ yield at near quantitative (~98%) 2-MTHF conversion on the borosilicate B-MWW, without a significant reduction in diene selectivities for at least 80 hours time-on-stream under low space velocity (0.85 g reactant/g cat./h) and high temperature (658 K) conditions. Finally, starting with iso-conversion levels (ca. 21-26%) and using total turnover numbers (TONs) accrued over the entire catalyst lifetime as the stability criterion, borosilicates were demonstrated to be significantly more stable than aluminosilicates under reaction conditions (~3-6x higher TONs).

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“…The hydrogen-rich coking species can attack key active sites at the zeolite surfaces with a net consequence of catalyst deactivation. Carbonaceous materials could be deposited inside the zeolite catalyst's pores and create diffusion difficulties [72][73][74][75][76]. This phenomenon is common during fast pyrolysis due to the production of char and polyaromatic coke precursors via oligomerization, dehydrogenation and other related reactions.…”

Section: Catalyst Deactivation In Fast Pyrolysismentioning

confidence: 99%

In situ fast pyrolysis of biomass with zeolite catalysts for bioaromatics/gasoline production: A review

Galadima

¹

,

Muraza

²

2015

Energy Conversion and Management

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Catalytic performance of boron and aluminium incorporated ZSM-5 zeolites for isomerization of styrene oxide to phenylacetaldehyde

Cited by 34 publications

References 41 publications

Dehydra-decyclization of 2-methyltetrahydrofuran to pentadienes on boron-containing zeolites

Dehydra-decyclization of 2-methyltetrahydrofuran to pentadienes on boron-containing zeolites

Dehydra-Decyclization of 2-Methyltetrahydrofuran to Pentadienes on Boron-Containing Zeolites

In situ fast pyrolysis of biomass with zeolite catalysts for bioaromatics/gasoline production: A review

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