100-78-7Relevant articles and documents
A comparative study on porous solid acid oxides as catalysts in the esterification of glycerol with acetic acid
Araujo, Jesuina C. S.,Campos, Adriana F.,Filho, Josué M.,Freire, Paulo T. C.,Lang, Rossano,Neto, Antonio B. S.,Oliveira, Alcineia C.,Rodriguez-Castellón, Enrique,Sousa, Francisco F. F.
, p. 57 - 67 (2020)
Acid catalysts comprising of porous SiAl, as well as molybdophosphoric heteropolyacid, supported SiAl nanotubes were synthesized. The characterizations were through scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), termoprogrammed ammonia desorption (NH3-TPD) and Fourier transform infrared spectroscopy (FTIR). Esterification of glycerol into acetins reaction was evaluated over two series of SiAl-based solids. Both series displayed very good activity as well as selectivity towards the acetins within a short reaction time. However, porous SiAl deactivated due to acid sites leaching in long-term catalytic runs. The tuning of the loadings of the molybdophosphoric amount on SiAl halloysite nanotubes leads to an increase in the selectivity towards the mono, di, and triacetins. These catalysts were also recycled up to three times, and a 17 percent of conversion and 100 percent of selectivity for triacetin were obtained due to the combination of acidity, stable structure and porosity of the molybdophosphoric supported SiAl nanotubes.
Graphene oxide as a facile solid acid catalyst for the production of bioadditives from glycerol esterification
Gao, Xiaoqing,Zhu, Shanhui,Li, Yongwang
, p. 48 - 51 (2015)
Graphene oxide (GO) has proved to be a highly active and reusable solid acid catalyst for glycerol esterification with acetic acid in the synthesis of bioadditives diacylglycerol (DAG) and triacylglycerol (TAG). The effects of reaction temperature, molar ratio of acetic acid to glycerol, catalyst amount and reaction time were investigated. A 90.2% combined selectivity of DAG and TAG with complete glycerol conversion was achieved at 120 °C for 6 h over GO. Final characterization shows that the active site of GO is the remaining SO3H group.
Esterification of glycerol with acetic acid using double SO 3H-functionalized ionic liquids as recoverable catalysts
Liu, Xiumei,Ma, Huiyuan,Wu, Yue,Wang, Chang,Yang, Miao,Yan, Peifang,Welz-Biermann, Urs
, p. 697 - 701 (2011)
Esterification of glycerol with acetic acid was studied using a series of Bronsted acidic ionic liquids as catalysts. The results indicate that double SO3H-functionalized ionic liquids show high catalytic activity and fair reusability even at very low catalyst loadings, while the conventional non-functionalized ionic liquids show poor activity. The Bronsted acidity-catalytic activity relationships were also investigated and the results showed that the sequence of the catalytic activity observed in the transformation was in good agreement with the Bronsted acidity order determined by the Hammett method. The Royal Society of Chemistry.
The effect of an electron-withdrawing group in the imidazolium cation: The case of nitro-functionalized imidazolium salts as acidic catalysts for the acetylation of glycerol
Morais, Eduardo M.,Grillo, Igor B.,Stassen, Hubert K.,Seferin, Marcus,Scholten, Jackson D.
, p. 10774 - 10783 (2018)
The acetylation of glycerol was achieved with high conversion and selectivity towards triacetin at low temperatures and short reaction times by using acidic imidazolium salts as catalysts. Moreover, the addition of a nitro group to the imidazolium cation affords a much more competent catalyst, indicating a significant effect provided by the simple electronic change in the imidazolium cation. Theoretical calculations revealed increased polarization of the acidic hydrogen bond on the nitrated salts, which may be related to their superior catalytic behavior when compared to the non-functionalized salts. Combining the preliminary experimental and theoretical results, it is possible to suppose that the catalytic activity of acidic imidazolium salts may be better comprehended by its Br?nsted acidities, but other parameters such as hardness, electronegativity, electrophilicity and ion-pair binding energy were also evaluated in order to investigate their effects in the acetylation of glycerol promoted by these acidic imidazolium salts.
A transesterification-acetalization catalytic tandem process for the functionalization of glycerol: The pivotal role of isopropenyl acetate
Calmanti, Roberto,Perosa, Alvise,Rigo, Davide,Selva, Maurizio
, p. 5487 - 5496 (2020)
At 30 °C, in the presence of Amberlyst-15 as a catalyst, a tandem sequence was implemented by which a pool of innocuous reactants (isopropenyl acetate, acetic acid and acetone) allowed upgrading of glycerol through selective acetylation and acetalization processes. The study provided evidence for the occurrence of multiple concomitant reactions. Isopropenyl acetate acted as a transesterification agent to provide glyceryl esters, and it was concurrently subjected to an acidolysis reaction promoted by AcOH. Both these transformations co-generated acetone which converted glycerol into the corresponding acetals, while acidolysis sourced also acetic anhydride that acted as an acetylation reactant. However, tuning of conditions, mostly by changing the reactant molar ratio and optimizing the reaction time, was successful to steer the set of all reactions towards the synthesis of either a 1?:?1 mixture of acetal acetates (97% of which was solketal acetate) and triacetin, or acetal acetates in up to 91% yield, at complete conversion of glycerol. To the best of our knowledge, a one-pot protocol with such a degree of control on the functionalization of glycerol via transesterification and acetalization reactions has not been previously reported. The procedure was also easily reproduced on a gram scale, thereby proving its efficiency for preparative purposes. Finally, the design of experiments with isotopically labelled reagents, particularly d4-acetic acid and d6-acetone, helped to estimate the contribution of different reaction partners (iPAc/AcOH/acetone) to the formation of final products. This journal is
Synthesis of bio-additives: Transesterification of ethyl acetate with glycerol using homogeneous or heterogeneous acid catalysts
Meireles, Bruno A.,Pereira, Vera Lu?cia P.
, p. 17 - 25 (2013)
A new catalytic route with potential practical interest to sustainable production of bioadditives from glycerol is described. Ethyl acetate was transesterified with glycerol, in the ratio glycerol:EtOAc 1:10, at 25 or 90 °C using 0.1 equiv. of H2SO4 or TsOH, as homogeneous catalysts. H2SO4 led to the total glycerol consumption in 2 h. In the equilibrium, attained in 9 h, 100percent yield of a diacetin:triacetin (55:45) mixture was formed. Using Amberlyst? 15 dry and Amberlyst? 16 wet in 1:30 glycerol:EtOAc ratio and reflux at 90 °C the total glycerol consumption was achieved in 2 and 10h, respectively. The lower reactivity of Amberlyst-16 wet was explained in terms of deactivation of acid sites and decrease in glycerol diffusion to the inner resin pores, both factors caused by adsorbed water. The kinetics of glycerol transformation and product distribution in the equilibrium in relation to the H2SO 4, Amberlyst-15 (dry) and Amberlyst-16 (wet) catalyzed reactions were measured.
Heteropolyacid-based ionic liquids as efficient homogeneous catalysts for acetylation of glycerol
Huang, Ming-Yu,Han, Xiao-Xiang,Hung, Chin-Te,Lin, Jann-Chen,Wu, Pei-Hao,Wu, Jung-Chung,Liu, Shang-Bin
, p. 42 - 51 (2014)
A series of homogeneous catalysts consisting of pyridinium propyl sulfobetaine (PPS), tungstophosphoric acid (TPA), and acetic acid (HOAc) have been synthesized and exploited for catalytic acetylation of glycerol (GL). Their acid properties were characterized by 31P NMR of trimethylphosphine oxide (TMPO) as the probe molecule, and the effects of acidic strength, PPS/TPA, TPA/GL, and HOAc/GL ratios as well as reaction temperature on catalytic performances during acetylation reaction were investigated. These water-tolerable PPS-TPA-HOAc catalysts, which tend to segregate from glycerol acetate products to form distinct biphasic liquid layers spontaneously after the reaction, were found to be highly efficient and durable for acetylation reaction under continuous operation conditions. Typically, a complete GL conversion may be achieved with a superior glycerol triacetate (GTA) selectivity of 86-99%. Moreover, the unique self-separation biphasic characteristics of the catalyst system facilitate facile separation of products and recycling of catalyst, rendering practical industrial applications in acetylation of alcohol.
Development of niobium containing acidic catalysts for glycerol esterification
Trejda, MacIej,Stawicka, Katarzyna,Dubinska, Anna,Ziolek, Maria
, p. 129 - 134 (2012)
Mesoporous silicate and niobiosilicate materials of SBA-15 type were prepared and post-synthesis modified with MPTMS, i.e. (3-mercaptopropyl) trimethoxysilane, followed by oxidation of thiol species. The samples obtained were characterised by different techniques (N2 adsorption/desorption, XRD, elemental and thermal analyses) and applied as catalysts in glycerol esterification with acetic acid. The focus was on the comparison of the role of niobium in the formation of sulphonic species and its stability in the post-synthesis modified materials (prepared within this work) with those, already published, prepared by one-pot synthesis method. The most important finding is that the presence of niobium in the SBA-15 structure improves the efficiency of -SH oxidation by hydrogen peroxide towards sulphonic species like in case of one-pot synthesised samples. However, contrary to the latter samples the presence of niobium does not increase the stability of the modifier (oxidized MPTMS). This has an impact on faster deactivation of samples prepared. Samples prepared with post-synthesis modification exhibit much higher activity in glycerol esterification.
The role of Nb in the formation of sulphonic species in SBA-15 and MCF functionalised with MPTMS
Trejda, Maciej,Stawicka, Katarzyna,Ziolek, Maria
, p. 130 - 135 (2012)
Mesoporous silica and niobiosilicate materials of SBA-15 and MCF types were prepared in the presence of MPTMS, i.e. (3-mercaptopropyl)trimethoxysilane and hydrogen peroxide. The samples obtained were characterised by different techniques (N2 adsorption/desorption, XRD, elemental and thermal analyses) and applied as catalysts in glycerol esterification with acetic acid. The role of niobium species on the formation of sulphonic species and stability of organosilane modifier was explored. The most important finding is that the addition of niobium to the synthesis gel improves the efficiency of -SH oxidation by hydrogen peroxide towards sulphonic species. This behaviour is not dependent on the type of structure of mesoporous materials (SBA-15 or MCF). However, the kind of mesoporous solid influences the efficiency of Nb incorporation and on the esterification process. MCF matrix improves the catalytic performance of the MPTMS modified catalyst.
Yttrium-grafted mesostructured SBA-3 catalyst for the transesterification of glycerol with methyl acetate to synthesize fuel oxygenates
Khayoon,Hameed
, p. 61 - 69 (2013)
The synthesis of di- and triacetyl glycerol (DAG and TAG) via the transesterification of glycerol with methyl acetate was investigated over series of solid acid catalysts prepared by grafting yttrium, 1-3.5 wt.%, into the framework of SBA-3 support. The p
