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.
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
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.].
