Ring Opening of Biomass-Derived Cyclic Ethers to Dienes over Silica/Alumina

Kumbhalkar, Mrunmayi D.; Buchanan, J. Scott; Huber, George W.; Dumesic, James A.

doi:10.1021/acscatal.7b01436

Cited by 42 publications

(82 citation statements)

References 29 publications

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“…E a value decreased followed the order 2Ni/S‐1 (119.87 ± 3.73 kJ/mol) > 2Ni@S‐1 (117.54 ± 2.89 kJ/mol) > 2Ni0.5Pt/S‐1 (110.49 ± 3.58 kJ/mol) > 2Ni0.5Pt@S‐1 (100.41 ± 3.43 kJ/mol) which also support the exceptional activity of 2Ni0.5Pt@S‐1 for steam reforming of n ‐dodecane. The Mears and Weisz–Prater criteria equation were employed to exclude the external and internal mass transfer limitations …”

Section: Resultsmentioning

confidence: 99%

“…E a value decreased followed the order 2Ni/S-1 Weisz-Prater criteria equation were employed to exclude the external and internal mass transfer limitations. 74,75 Encapsulated bimetallic alloy catalyst exhibited not only exceptional activity and stability, but also high hydrogen selectivity. For 2Ni0.5Pt@S-1 and 2Ni@S-1, hydrogen selectivity was as high as 69.9 and 70.3%, respectively.…”

Section: Catalyst Characteristicsmentioning

confidence: 99%

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Selective steam reforming of n‐dodecane over stable subnanometric NiPt clusters encapsulated in Silicalite‐1 zeolite

et al. 2020

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Multimetallic nanocatalysts have attracted increasing attention for steam reforming owing to highly exposed active sites, but often suffering from severe sintering. Herein, we design subnanometric Ni‐Pt bimetal clusters (ca. 1.7 nm) encapsulated in Silicalite‐1 zeolite (2Ni0.5Pt@S‐1) through ligand‐stabilized method to prevent sintering by fixing the metal into microporous channels. In the steam reforming of n‐dodecane test, 2Ni0.5Pt@S‐1 gave an excellent activity and stability with a decrease of conversion only 4% at 600°C for 4 hr, which was about a quarter that of 2Ni0.5Pt/S‐1 synthesized by co‐impregnation method, ascribing to superior sinter‐resistance of encapsulation structure. Moreover, 2Ni0.5Pt@S‐1 exhibited a higher H2 selectivity up to 69.9% than that of 2Ni0.5Pt/S‐1 (64.4%), owing to suppressed methanation reaction based on subnanometric clusters. Shape‐selective steam reforming of n‐dodecane and ofm‐xylene was also observed, because of m‐xylene could hardly diffuse into the zeolite channels due to its bulky molecular size, further preventing potential deactivation by tars in reforming process.

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Section: Resultsmentioning

confidence: 99%

Section: Catalyst Characteristicsmentioning

confidence: 99%

Selective steam reforming of n‐dodecane over stable subnanometric NiPt clusters encapsulated in Silicalite‐1 zeolite

et al. 2020

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“…Myrcene and Far are both found in nature, but can also be produced by pyrolysis of β‐pinene and microbial pathways from glucose, respectively. Although, there are new bio‐based pathways to synthesize butadiene and isoprene, myrcene and Far are made up of multiple isoprene units, which can provide different rheological properties. It was shown that bottlebrush polymers with densely packed, long side chains improve elastic properties .…”

Section: Introductionmentioning

confidence: 99%

Nitroxide‐Mediated Polymerization of Bio‐Based Farnesene with a Functionalized Methacrylate

Luk

Marić

2019

Macro Reaction Engineering

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polymers with controlled architectures. [11,12] Styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene (SIS) triblock copolymers have long been commercialized too, such as the Kraton family of thermoplastic elastomers, which are made by anionic polymerization. [13,14] While many industrial applications use free radical polymerization, CRP precisely controls the molecular architecture of polymer chains, therefore making homopolymers, diblock and triblock copolymers with narrow molecular weight distributions (MWDs) and low dispersity. [15] Ionic polymerization is a truly "living" method, but it is intolerant to functional monomers and impurities. [16] CRP, more properly defined as reversible deactivation radical polymerization (RDRP), is a newer, more versatile technique to control the polymerization of free radicals. It utilizes activationdeactivation equilibrium or reversible chain transfer to suppress irreversible termination such that the propagating radical is primarily in its dormant state. [17] Amongst the several types of RDRP, atom transfer radical polymerization (ATRP) [18][19][20] and reversible additionfragmentation transfer (RAFT) [21][22][23] can polymerize a wide variety of functional monomers like vinyl esters and (meth) acrylates. This study will focus on nitroxide-mediated polymerization (NMP) as it is particularly adept for polymerization of styrene-diene systems. [24][25][26] NMP is able to polymerize functionalized styrene and acrylate monomers successfully, [27] however it is limited in its ability to maintain active chain ends in the polymerization of methacrylates. [28,29] It was discovered that the rate of dissociation (k d ) is very large because of steric stabilization of the propagating methacrylate radical, and the rate of combination (k c ) is very low due to steric hindrance provided by the bulky SG1-nitroxide (N-tert-butyl-N-[1-diethylphosphono-(2,2dimethylpropyl)] nitroxide). Consequently, the activationdeactivation equilibrium (K eq = k d /k c ) is high, resulting in termination by disproportionation. [30] To overcome this, small amounts of controlling comonomer like styrene or acrylonitrile can be added to effectively lower K eq . [28,31] Furthermore, the SG1-based nitroxide, BlocBuilder, can be modified with an N-succinimidyl ester group (N-succinimidyl modified commercial BlocBuilder [NHS-BB]) to better control the polymerization of methacrylates, [32] and successful polymerization of Nitroxide-Mediated Polymerization Farnesene (Far) is a bio-based terpene monomer that is similar in structure to commercially used dienes like butadiene and isoprene. Nitroxide-mediated polymerization (NMP) is adept for the polymerization of dienes, but not particularly effective at controlling the polymerization of methacrylates using commercial nitroxides. In this study, Far is statistically copolymerized with a functional methacrylate, glycidyl methacrylate (GMA), by NMP using N-succinimidyl modified commercial BlocBuilder (NHS-BB) initiator. Reactivity ratios are determined to be r Far = ...

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“…In the first step, the deoxydehydration (DODH) of xylitol was conducted at 235 • C in the presence of formic acid to give 2,4-pentadien-1-ol, 1-formate (2E), with an optimized yield of 62.9%, followed by deoxygenation to obtain 1,3-pentadiene over a Pd/C catalyst at 100 • C. The total yield of 1,3-pentadiene reached 51.8%. Kumbhalkar et al [101] employed 2-methyltetrahydrofuran (2-MTHF) which can be easily obtained from biomass-derived intermediates (levulinic acid and furfural, etc. ), as the starting material to produce 1,3-pentadiene in a continuous system.…”

Section: Synthesis Of Isoprenementioning

confidence: 99%

“…The total yield of 1,3-pentadiene reached 51.8%. Kumbhalkar et al [101] employed 2-methyltetrahydrofuran (2-MTHF) which can be easily obtained from biomass-derived intermediates (levulinic acid and furfural, etc. ), as the starting material to produce 1,3-pentadiene in a continuous system.…”

Section: Synthesis Of Isoprenementioning

confidence: 99%

Synthesis of 1,3-Butadiene and Its 2-Substituted Monomers for Synthetic Rubbers

Liu

et al. 2019

Catalysts

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Synthetic rubbers fabricated from 1,3-butadiene (BD) and its substituted monomers have been extensively used in tires, toughened plastics, and many other products owing to the easy polymerization/copolymerization of these monomers and the high stability of the resulting material in manufacturing operations and large-scale productions. The need for synthetic rubbers with increased environmental friendliness or endurance in harsh environments has motivated remarkable progress in the synthesis of BD and its substituted monomers in recent years. We review these developments with an emphasis on the reactive routes, the products, and the synthetic strategies with a scaling potential. We present reagents that are primarily from bio-derivatives, including ethanol, C4 alcohols, unsaturated alcohols, and tetrahydrofuran; the major products of BD and isoprene; and the by-products, activities, and selectivity of the reaction. Different catalyst systems are also compared. Further, substituted monomers with rigid, polar, or sterically repulsive groups, the purpose of which is to enhance thermal, mechanical, and interface properties, are also exhaustively reviewed. The synthetic strategies using BD and its substituted monomers have great potential to satisfy the increasing demand for better-performing synthetic rubbers at the laboratory scale; the laboratory-scale results are promising, but a big gap still exists between current progress and large scalability.

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Ring Opening of Biomass-Derived Cyclic Ethers to Dienes over Silica/Alumina

Cited by 42 publications

References 29 publications

Selective steam reforming of n‐dodecane over stable subnanometric NiPt clusters encapsulated in Silicalite‐1 zeolite

Selective steam reforming of n‐dodecane over stable subnanometric NiPt clusters encapsulated in Silicalite‐1 zeolite

Nitroxide‐Mediated Polymerization of Bio‐Based Farnesene with a Functionalized Methacrylate

Synthesis of 1,3-Butadiene and Its 2-Substituted Monomers for Synthetic Rubbers

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