24969-06-0Relevant articles and documents
Fully utilizing seeds solution for solvent-free synthesized nanosized TS-1 zeolites with efficient epoxidation of chloropropene
Chai, Yongming,Li, Bin,Li, Yichuan,Liu, Hanfang,Liu, Jia,Liu, Yanru,Ran, Saisai,Wang, Fupeng,Wang, Lei,Wang, Yu,Xie, Huijie,Ye, Tiantian
, (2021/12/27)
Nanosized titanium silicalite-1 (TS-1) demonstrates excellent catalytic ability in the selective catalytic oxidation reaction. However, their synthesis process is usually complicated with low yield under hydrothermal conditions, which is not in line with the concept of green chemistry. Herein, via fully utilizing untreated seeds solution, we report firstly an entirely green strategy for solvent-free synthesizing anatase-free nanosized TS-1 zeolite. The success lies in the fully utilization of seeds solution which is composed of supersaturated structure directing agent (TPAOH), unreacted silica source, water and formed MFI seeds (silicalite-1) without external purification. In the followed solvent-free synthesis of final nanosized TS-1 product, no additional TPAOH is added, which greatly reduces the synthesis cost and synthetic procedure and maintains a high product yield. The obtained nanosized TS-1 zeolite without anatase phase has high crystallinity, large specific surface area. More importantly, the nanosized TS-1 (Si/Ti ?= ?77) catalysts exhibit excellent catalytic ability for the epoxidation of chloropropene with 40.0% conversion and 97.6% selectivity. This sustainable and green synthesis method opens up a new way to regulate nanosized zeolite.
An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
Solís-Mu?ana, Pablo,Salam, Joanne,Ren, Chloe Z.-J.,Carr, Bronte,Whitten, Andrew E.,Warr, Gregory G.,Chen, Jack L.-Y.
supporting information, p. 3207 - 3213 (2021/06/01)
An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil-water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems. (Figure presented.).
Selective synthesis of epichlorohydrin: Via liquid-phase allyl chloride epoxidation over a modified Ti-MWW zeolite in a continuous slurry bed reactor
Ding, Luoyi,Yin, Jinpeng,Tong, Wen,Peng, Rusi,Jiang, Jingang,Xu, Hao,Wu, Peng
, p. 331 - 342 (2021/01/11)
The epoxidation of allyl chloride (ALC) to epichlorohydrin (ECH) with H2O2 using a piperidine (PI)-modified Ti-MWW catalyst (Ti-MWW-PI) in a continuous slurry reactor was investigated to develop an efficient reaction system for the corresponding industrial process. The reaction parameters, including solvent, reaction temperature, t-butanol/ALC mass ratio, ALC/H2O2 molar ratio, weight hourly space velocity of H2O2, and the addition amount of ammonia, were studied in detail to pursue high H2O2 conversion and ECH selectivity. A long catalytic lifetime of 244 h was achieved at high H2O2 conversion (>97.0%) and ECH selectivity (>99.8%) under optimized reaction conditions. The crystallinity was well maintained for the deactivated Ti-MWW-PI catalyst, which was regenerated by a combination of calcination and piperidine treatment. This journal is
RUTHENIUM COMPLEX AND PRODUCTION METHOD THEREOF, CATALYST, AND PRODUCTION METHOD OF OXYGEN-CONTAINING COMPOUND
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Paragraph 0145-0148, (2021/01/29)
PROBLEM TO BE SOLVED: To provide a ruthenium complex that is particularly useful as a catalyst for oxidizing a substrate having a carbon-hydrogen bond. SOLUTION: The ruthenium complex represented by the general formula (i) or a cis conformer thereof is provided. In the general formula (i), R1 represents H, a phenyl group or a substituted phenyl group; R2 represents H, a phenyl group or an alkyl group; L1 represents halogen or water molecule; L2 represents triphenylphosphine, pyridine, imidazole or dimethylsulfoxide; X represents halogen; and n represents 1 or 2. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPO&INPIT
Epoxidation of Allyl Chloride in the Presence of Tungsten Oxo–Peroxo Heteropoly Compounds of P(V), As(V), and Si(IV) Under Phase-Transfer Catalysis Conditions
Panicheva,Meteleva,Ageikina,Panichev
, p. 1270 - 1274 (2021/10/20)
Abstract: This study investigates the behavior of nonmetals in tungsten oxo–peroxoheteropoly compounds in the reaction of allyl chloride epoxidation. Thecatalytic efficiency in epoxidation was shown to increase in the followingorder: Si(IV) As(V) P(V). Synergism in allyl chloride epoxidation wasdemonstrated for the first time for mixtures of tungsten oxo–peroxo heteropolycompounds of P and As, as well as P and Si. It was also shown that mixturesconsisting of 70% P + 30% Si and 75% P + 25% As exhibit the highest catalyticactivity. Finally, the article suggests a mechanism for the synergisticeffect. [Figure not available: see fulltext.].
A method for efficient preparation of epichlorohydrin by biomass glycerol
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Paragraph 0040-0041; 0051-0052; 0062-0063; 0073, (2022/01/10)
The present invention discloses a method for efficiently preparing epichlorohydrin by biomass glycerol, comprising the following steps: 1) the mass ratio of 1: 0.06 ~ 0.08 of biomass glycerol and a composite catalyst poured into the reactor, and then using an ultrasonic probe to extend into the reactor, 2) step 1) after the end of the reaction, the resulting material is cooled to room temperature and transferred to the reaction vessel, maintaining a temperature of 15 ~ 30 ° C, and then adding an alkaline cyclizer for the reaction; 3) after the completion of the reaction to filter the resulting solids, The filtrate is a solution of epichlorohydrin oxide; the glycerol of the present invention can be completely converted, the intermediate product dichloropropanol yield is high, and the selectivity of collecting 1,3-dichloropropanol is improved, which accelerates the reaction rate; and the process can be co-produced with biodiesel and chlor-alkali industry, and the industrialization prospect is good.
Mixed tetradentate NHC/1,2,3-triazole iron complexes bearing cis labile coordination sites as highly active catalysts in Lewis and Br?nsted acid mediated olefin epoxidation
Dyckhoff, Florian,Jakob, Christian H. G.,Kühn, Fritz E.,Nguyen, Linda,Reich, Robert M.,Schlagintweit, Jonas F.
, p. 144 - 152 (2020/02/04)
Two bio-inspired non-heme iron complexes bearing mixed tetradentate N-heterocyclic carbene/1,2,3-triazole ligands with cis labile coordination sites are reported. The compounds are studied in olefin epoxidation catalysis using H2O2 as oxidant. Sc(OTf)3, HClO4 and HOAc are applied as additives resulting in significant improvement of catalytic performance. Under optimized conditions the most active catalyst exhibits activities of 76,000 turnovers per hour, which is the highest reported value for an iron(II) catalyst. The complexes reveal comparably high stability and enable the challenging epoxidation of functionalized olefins. These results prove 1,2,3-triazoles to be promising and tunable ligands for iron catalyzed oxidation reactions.
Controlling the Morphology and Titanium Coordination States of TS-1 Zeolites by Crystal Growth Modifier
Chang, Xinyu,Chen, Ziyi,Hu, Dianwen,Jia, Mingjun,Li, Yingying,Song, Xiaojing,Yang, Xiaotong,Yu, Jihong,Zhang, Hao,Zhang, Peng,Zhang, Qiang,Zhang, Tianjun
supporting information, p. 13201 - 13210 (2020/10/02)
Developing an effective strategy to synthesize perfect titanosilicate TS-1 zeolite crystals with desirable morphologies, enriched isolated framework Ti species, and thus enhanced catalytic oxidation properties is a pervasive challenge in zeolite crystal engineering. We here used an amino acid l-carnitine as a crystal growth modifier and ethanol as a cosolvent to regulate the morphologies and the Ti coordination states of TS-1 zeolites. During the hydrothermal crystallization process, the introduced l-carnitine can not only tailor the anisotropic growth rates of zeolite crystals but also induce the formation of uniformly distributed framework Ti species through building a suitable chemical interaction with the Ti precursor species. Condition optimizations could afford the generation of perfect hexagonal plate TS-1 crystals and elongated platelet TS-1 crystals enriched in tetrahedral framework Ti sites (TiO4) or mononuclear octahedrally coordinated Ti species (TiO6). Both samples showed significant improvement in catalytic activity for the H2O2-mediated epoxidation of alkenes. In particular, the elongated platelet TS-1 enriched in "TiO6"species afforded the highest activity in 1-hexene epoxidation, with a turnover frequency (TOF) of up to 131 h-1, which is approximately twice as high as that of the conventional TS-1 zeolite (TOF: 65 h-1) and even higher than those of the literature-reported TiO6-containting TS-1 catalysts derived from the hydrothermal post-treatment of TS-1 zeolites. This work demonstrates that the morphologies and the titanium coordination states of TS-1 zeolites can be effectively tuned by directly introducing suitable crystal growth modifiers, thus providing new opportunities for developing highly efficient titanosilicate zeolite catalysts for important catalytic applications.
Visible-light assisted of nano Ni/g-C3N4 with efficient photocatalytic activity and stability for selective aerobic C?H activation and epoxidation
Akrami, Zahra,Hosseini-Sarvari, Mona
supporting information, (2020/10/13)
A selective, economical, and ecological protocol has been described for the oxidation of methyl arenes and their analogs to the corresponding carbonyl compounds and epoxidation reactions of alkenes with molecular oxygen (O2) or air as a green oxygen source, under mild reaction conditions. The nano Ni/g-C3N4 exhibited high photocatalytic activity, stability, and selectivity in the C?H activation of methyl arenes, methylene arenes, and epoxidation of various alkenes under visible- light irradiation without the use of an oxidizing agent and under base free conditions.
Epoxidation of allyl chloride with H2O2 catalyzed by three structurally related quaternary ammonium modified polyoxophosphotungstates
Cui, Yu,Jiang, Xuchuan,Sun, Guoxin,Sun, Junhua,You, Qi,Zhao, Xiuxian
, (2020/10/09)
The one-step epoxidation of allyl chloride has always been a great challenge for the industrial production. The key of this technology is to find efficient and friendly catalyst. In this paper, three structurally related quaternary ammonium modified polyoxophosphotungstates were synthesized by green and facile method. Among them, [C16H33(CH3)3N]3PW4O24 and [π-C5H5NC16H33]3PW4O24 are reaction-controlled phase transfer catalyst (RPTC) and [(C18H37)2(CH3)2N]3PW4O24 is temperature-controlled phase transfer catalyst (TPTC). All three catalysts could achieve the epoxidation of allyl chloride with equimolar H2O2 under solvent-free and mild conditions. Moreover, the catalysts exhibited excellent catalytic performance and reusability. The catalytic mechanism was explored by FT-IR spectroscopy. The results of kinetic experiments show that the chain length of alkanes and heterocyclic structure of cations have a great influence on the catalytic activity of the catalysts.
