First Evidence of the Double-Bond Formation by Deoxydehydration of Glycerol and 1,2-Propanediol in Ionic Liquids (original) (raw)
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Ionic Liquids as Homogeneous Catalysts for Glycerol Oligomerization
Polymers, 2022
Ionic liquids (ILs) were used for the first time as catalysts for the glycerin condensation reaction. A series of imidazolium and ammonium ionic liquids differing in the length of the alkyl substituent (C2, C12, and C14) and the type of anion (Br−, CH3COO−, and NaHPO4−) were synthesized using a typical two-step method. The structure of the obtained ILs was confirmed by nuclear magnetic resonance 13C NMR, and their base power was determined on the basis of the Hammett function. The oligomerization of glycerin with the participation of the obtained ionic liquids and, for comparison, in the presence of a homogeneous basic catalyst Na2CO3, was carried out for 3 h at 180 °C, under a pressure of 0.4 bar, where the highest conversion, i.e., 92%, was obtained against 1-dodecyl-N, N, N-triethylammonium acetate. The course of the reaction was monitored using a reaction system coupled with a FTIR spectrometer, which allowed for the tracking of changes in product concentration over time and the...
ChemistrySelect, 2016
Brønsted acid ionic liquids (BAILs) have been prepared and applied for the first timeto the best of 17 our knowledgeas efficient catalysts in the acetylation of glycerol with acetone to form solketal ((2,2-18 dimethyl-1,3-dioxolan-4-yl)methanol) at very mild reaction conditions (room temperature) and short 19 reaction times. The BAILs showed a superior catalytic performance in terms of both conversion and 20 selectivity compared to the common mineral acid methanesulfonic acid as well as to other reported 21 homogeneous and heterogeneous catalysts. Catalyst reusability was demonstrated with one of the 22 BAILs (BAIL-1), which was recovered and reused by a simple procedure in four consecutive reaction 23 runs without any loss of catalytic activity and selectivity. Thus, the BAILs combine the advantages of 24 both homogeneous and heterogeneous catalysis with respect to excellent conversion and selectivity as 25 well as easy recyclability. 26 27 28 Manuscript Click here to download Manuscript manuscript(ChemistrySelect).docx 35 Biodiesel (fatty acid methyl ester; FAME) is already an applied renewable fuel produced in large-scale 36 by transesterification of triglycerides from plant or animal oil with methanol in the presence of acid or 37 basic catalysts. 2 Due to its physicochemical properties, biodiesel is practically compatible with 38 commercial diesel engines and provides similar fuel features as the fossil diesel. Moreover, the 39 renewable nature offer added benefits such as, e.g. less toxicity, less emissions and biodegradation. 3 40 Also notably, the synthesis of biodiesel yields glycerol in amounts corresponding to 10 wt. % of the 41 produced biodiesel as a potentially valuable resource. 4 Glycerol has many applications areas in, for 42 example, cosmetics, foods, pharmaceuticals and polymers, 5 but the global biodiesel production 43 generates amounts of glycerol thatif used-would saturate the current market and decrease its 44 commercial value. Thus, a different strategy is to utilize glycerol as an attractive feedstock for 45 production of value-added chemicals. 7,8
Journal of Industrial and Engineering Chemistry, 2010
In this study, ionic liquids immobilized on mesoporous MCM41 were prepared and their catalytic performance was tested in the synthesis of glycerol carbonate from transesterification of ethylene carbonate with glycerol. The ionic liquids were generated on chloropropyl functionalized MCM41 (CP-MCM41) via the immobilization of trialkylamines. The quaternary salt ionic liquid immobilized on MCM41 (RNX-MCM41) was characterized using a number of physical–chemical measurements including XRD, BET, 13C and 29Si MAS-NMR. Their catalytic performances were tested in a batch reactor. The influence of the structure of the quaternary ammonium salt and reaction parameters like temperature and reaction time was investigated. It was found that RNX-MCM41 with a longer alkyl chain length showed much better catalytic activity. High temperature and longer reaction time were favorable for the reactivity of RNX-MCM41. The catalyst can be reused for the reaction up to three consecutive runs without any considerable loss of its initial activity.
Synthesis of glycidol from glycerol and dimethyl carbonate using ionic liquid as a catalyst
Catalysis Communication, 2012
Transesterification of dimethyl carbonate with glycerol has been investigated using various ionic liquids as catalysts. Synthesis of glycidol with high selectivity (78%) has been achieved using tetramethylammonium hydroxide ([TMA][OH]) as a catalyst at 80°C. Effect of various reaction conditions on the activity and selectivity was investigated and catalyst concentration had a significant influence on conversion as well as selectivity to glycidol. Activity as well as selectivity of the catalyst decreased significantly with increase in moisture content. Recycle experiment indicated slight drop in glycerol conversion and selectivity to glycidol because of dilution of reaction mixture and also the presence of products from the initial experiment.
Application of ionic liquids as recyclable green catalysts for selective alkylation of phenol
Separation and Purification Technology, 2018
Alkylation of phenol with tert-butyl alcohol (TBA) as an alkylating agent was studied in presence of different ionic liquid catalysts. The synthesized ionic liquid catalysts were characterized by 1 H NMR and TGA. It was proved that heteropoly anion-based ionic liquid catalyst is potentially promising candidates in production of 2,4-di-tert-butylphenol (2,4-DTBP) and 2,6-di-tert-butylphenol (2,6-DTBP) with high activity and selectivity. Maximum phenol conversion of 93% was achieved at the molar ratio of phenol:TBA:IL is 1:2:1, reaction time of 3 h and reaction temperature of 80°C with 2,4-DTBP and 2,6-DTBP selectivity of 48 and 41%, respectively.
Asian Journal of Chemistry 25 (2013) 5, 2722-2728., 2012
Ionic liquid 1,1,3,3-tetramethylguanidium lactate was immobilized on three solid supports, MCM-41, silica-gel and attapulgite (Atta), by different methods. The prepared materials were used to catalyze the reaction of propylene oxide and methanol to produce propylene glycol methyl ether. 1-Methoxy-2-propanol was the predominant product. The influence of the amount of the catalyst, molar ratio of the reactants, reaction temperature and time on the yield and selectivity was studied. The three catalysts proved to be efficient reusable catalysts for the reaction.
Research on Chemical Intermediates, 2011
Ionic liquids (ILs) immobilized onto a structurally modified Merrifield peptide resin (MPR) were prepared through the reaction of imidazole with alkoxylated MPR. Elemental analysis and scanning electron microscopy (SEM) observations showed that the immobilized IL groups were effectively incorporated on the support. The MPR-supported ILs (MPR-ILs) proved to be effective heterogeneous catalysts for the synthesis of glycerol carbonate (GC) from glycerol and urea. MPR-ILs with longer alkyl chain linkers and fewer sterically hindered counteranions resulted in higher conversion of glycerol. High temperature, high degree of vacuum and the presence of zinc oxide co-catalyst were favorable for glycerol conversion. The MPR-ILs could be reused in up to three consecutive runs without significant loss of their catalytic activity.
Research on Chemical Intermediates, 2018
A novel dicationic ionic liquid, N,N,N 0 ,N 0-tetramethyl-N,N 0-bis(sulfo)ethane-1,2-diaminium mesylate [TMBSED][OMs] 2), has been produced, and identified by analysis of its 1 H NMR, 13 C NMR, FT-IR, mass and thermal gravimetric data. Thereafter, it has been utilized as a highly effectual, homogeneous and dual-functional catalyst to promote the multi-component reaction of ethyl acetoacetate, hydroxylamine hydrochloride and arylaldehydes under solvent-free conditions for the synthesis of 3-methyl-4-arylmethylene-isoxazole-5(4H)-ones. Due to the dual-functionality of [TMBSED][OMs] 2 (possessing acidic and basic sites), and also having two sites of each, it was a highly effective and general catalyst for the synthesis. Moreover, a plausible and attractive mechanism based on the dual-functionality of the catalyst has been proposed.
Production of glycerol carbonate from glycerol with aid of ionic liquid as catalyst
Green production of glycerol 1,2-carbonate with an environmentally friendly catalyst was proposed. Screening and optimisation of the catalysts were comprehensively performed. The basic ionic liquid (emim[Ac]) showed best catalytic activity and recyclability. Detail understanding on the glycerol-catalysts and glycerol 1,2-carbonate-catalysts interactions has been well explored. a b s t r a c t The rapid growth of biodiesel industry has led to a large surplus of its major unintentional byproduct particularly glycerol. Thus, finding a new application is necessary to convert glycerol to value added products. In this study, glycerol has been subjected to a transesterification reaction to synthesis glycerol carbonate (GC) over several selected ammonium and imidazolium-based ionic liquids (ILs) as catalysts. It is believed that the variation of catalytic performance between ILs was due to the anion strength of ILs. The glycerol conversion, yield and selectivity of GC were followed the anion order of [Ac] > [Dca] > [Fmt] > [DMP] > [NO 3 ] > [Cl] > [BF 4 ]. Effects of reaction temperature, time, diethyl carbonate (DEC)/glyc-erol molar ratio and catalyst loading on glycerol conversion and GC yield have been analysed. The IL, 1-ethyl-3-methylimidazolium acetate (emim[Ac]) shows best performance under solvent-free with conversion of glycerol and GC yield reached highest at 93.50% and 88.70%, respectively under reaction temperature of 120 °C reaction time of 2 h, DEC/glycerol molar ratio of 2 and catalyst loading of 0.5 mol%. Also, this emim[Ac] can be reused as catalyst at least three times without any significant reduction in conversion, yield and selectivity. Reaction mechanism of the transesterification reaction catalysed by emim[Ac] has been proposed in this study.