4361-60-8Relevant academic research and scientific papers
Structure–Activity Relationships of WOx-Promoted TiO2–ZrO2 Solid Acid Catalyst for Acetalization and Ketalization of Glycerol towards Biofuel Additives
Baithy, Mallesham,Mukherjee, Deboshree,Rangaswamy, Agolu,Reddy, Benjaram M.
, (2021/07/25)
Abstract: WOx-promoted TiO2–ZrO2 solid acid catalyst was prepared and applied in the catalytic acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. The presence of WOx promoter and TiO2 remarkably improved the catalytic activity of ZrO2. Approximately, 100% glycerol conversion was evidenced with non-bulky aliphatic aldehydes and ketones like, propanol and cyclohexanone. The physical characterization of WOx-promoted TiO2–ZrO2, revealed a higher formation of tetragonal crystalline phase of ZrO2, over monoclinic. The total surface acidity and the ratio of Br?nsted to Lewis acidic site concentrations were determined by NH3-TPD and pyridine-chemisorbed FTIR spectroscopy, respectively. A considerably higher concentration of Lewis acidic sites, ~ 213.29?μmol/gm, was evidenced on the WOx-promoted TiO2–ZrO2 catalyst surface. Catalytic activity study revealed a direct correlation between the surface Lewis acidic site concentration and the activity of catalyst. This significant observation indicated the key role of Lewis acidic sites in this catalytic process. The WOx-promoted TiO2–ZrO2 catalyst was also considerably stable and showed good performance in the acetalization/ketalization of glycerol with other substituted carbonyl compounds. Graphic Abstract: The WOx-promoted TiO2–ZrO2 solid acid catalyst exhibits superior catalytic performance for acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. [Figure not available: see fulltext.].
A green approach for the preparation of a surfactant embedded sulfonated carbon catalyst towards glycerol acetalization reactions
Auroux, Aline,Chowdhury, Biswajit,Das, Avik,Ghosh, Anindya,Sen, Debasis,Singha, Aniruddha
, p. 4827 - 4844 (2020/08/21)
The green synthesis of heterogeneous catalysts often requires a solid-state reaction pathway. In this work, a cationic surfactant (CTAB) embedded sulfonated carbon catalyst was prepared via a sustainable route with the aim of having controlled surface hydrophobicity and acidity for glycerol acetalization reactions. The main objective of this study was to tune the hydrophobicity and acidic site density, either via adding a cationic surfactant or changing the carbon to sulphur ratio. The as-synthesized catalyst was characterized via XRD, N2 adsorption/desorption, SAXS, FESEM, FTIR, pyridine-IR, high-temperature DR-FTIR, TGA, 13C-NMR, Raman, and XPS techniques. The incorporation of a cationic surfactant (CTAB) reduces the surface area but increases the acidic site density to a greater extent. The bonding between the surfactant (CTAB) and surface hydroxyl groups was elucidated via XPS analysis. DR-FTIR studies implied that the -SO3H groups are strongly bonded to the carbon network, while the lower amount of water mass loss seen from TGA studies showed the substantial improvement in surface hydrophobicity after modification with the surfactant. Moreover, the combination of acidic site density and hydrophobicity played a key role in attaining around 90% glycerol conversion and 98% solketal selectivity under ambient conditions. Notably, characterization of the used catalyst revealed that the loss of activity is mainly related to a drop in hydrophobicity, which occurs due to the loss of surfactant during washing with methanol.
Acetalization of glycerol with ketones and aldehydes catalyzed by high silica Hβ zeolite
Poly, Sharmin Sultana,Jamil, Md.A.R.,Touchy, Abeda S.,Yasumura, Shunsaku,Siddiki, S.M.A. Hakim,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
, (2019/09/20)
In this work, proton-exchanged *BEA zeolite with a high Si/Al ratio of 75 (Hβ-75), was demonstrated as an effective catalyst for the acetalization of glycerol with carbonyl compounds. This catalyst system was applicable to various substrates and reusable for at least 4 times with slight decrease in activity. The turnover frequency, based on acid site concentration, increased as a function of Hβ Si/Al ratio, indicating the importance of the zeolite hydrophobic surface properties. The origin of the high efficiency exhibited by Hβ-75 is quantitatively discussed based on kinetic studies, hydrophobicity, and acid site concentration.
Ketalization of ketones to 1,3-dioxolanes and concurring self-aldolization catalyzed by an amorphous, hydrophilic SiO2-SO3H catalyst under microwave irradiation
Barbosa, Sandro L.,Ottone, Myrlene,De Almeida, Mainara T.,Lage, Guilherme L.C.,Almeida, Melina A.R.,Nelson, David Lee,Dos Santos, Wallans T.P.,Clososki, Giuliano C.,Lopes, Norberto P.,Klein, Stanlei I.,Zanatta, Lucas D.
, p. 1663 - 1671 (2018/06/29)
The amorphous, mesoporous SiO2-SO3H catalyst with a surface area of 115 m2 g-1 and 1.32 mmol H+ per g was very efficient for the protonation of ketones on a 10percent (m/m) basis, and the catalyst-bound intermediates can be trapped by polyalcohols to produce ketals in high yields or suffer aldol condensations within minutes under low-power microwave irradiation. The same catalyst can easily reverse the ketalization reaction. Printed in Brazil-
Graphene-promoted acetalisation of glycerol under acid-free conditions
Oger, Nicolas,Lin, Yuting F.,Le Grognec, Erwan,Rataboul, Franck,Felpin, Fran?ois-Xavier
, p. 1531 - 1537 (2016/04/04)
Serendipity led us to unveil unexpected and uncovered properties of graphene for the acetalisation of glycerol with both aldehydes and ketones, furnishing an acid-free process for fuel bio-additive candidates. Mechanistic studies ruled out the intervention of residual acidic species or metallic cations at the surface of graphene, and therefore, the peculiar electronic properties of graphene are most probably responsible for this unforeseen reactivity. Recycling studies revealed the robustness of graphene under the experimental conditions since only a marginal erosion of the reaction yield was observed after six cycles.
Indium(III) triflate catalysed transacetalisation reactions of diols and triols under solvent-free conditions
Smith, Brendan M.,Kubczyk, Tomasz M.,Graham, Andrew E.
experimental part, p. 7775 - 7781 (2012/09/21)
Acyclic acetals and ketals undergo transacetalisation in the presence of catalytic quantities of indium(III) triflate (In(OTf)3) and diols or triols under solvent-free conditions to generate the corresponding cyclic acetals and ketals in excellent yield. The methodology has been further developed to encompass a tandem acetalisation-acetal exchange protocol, which provides a facile and high yielding route to cyclic ketals from unreactive ketones under very mild reaction conditions.
Regio- And stereoselective intermolecular hydroalkoxylation of alkynes catalysed by cationic gold(I) complexes
Corma, Avelino,Ruiz, Violeta R.,Leyva-Perez, Antonio,Sabater, Maria J.
supporting information; experimental part, p. 1701 - 1710 (2010/10/04)
Vinyl ethers and ketals are obtained from the reaction of phenylacetylene derivatives and dimethyl acetylenedicarboxylate (DMAD) with alcohols in good yields and levels of stereoselectivity by using cationic gold(I)-phosphine complexes as catalysts. By choosing the appropriate phosphine, the selective formation of the Z or the E isomer of the vinyl ether can be tuned, and the undesired formation of the ketal can be controlled. The isomerisation of fumarates (Z-isomer) to maleates (E-isomer) is a gold-catalysed process that can be conducted in onepot. When using polyols, 5-membered cyclic ketals are easily isolated by extraction with hexane and the gold complex can be reused.
Highly regioselective preparation of 1,3-Dioxolane-4-methanol derivatives from glycerol using phosphomolybdic acid
Fadnavis, Nitin Wasantrao,Reddipalli, Gowri Sankar,Ramakrishna, Gadupudi,Mishra, Mithilesh Kumar,Sheelu, Gurrala
experimental part, p. 557 - 560 (2009/07/11)
Phosphomolybdic acid (PMA) forms a blue-colored complex with glycerol in a 1:10 molar ratio. The glycerolato complex catalyzes conversion of glycerol into 1,3-dioxolane-4-meth-anol derivatives with complete regiospecificity in high yields (>95%) and the catalyst can be recycled up to ten times without loss of activity or regiospecificity. Georg Thieme Verlag Stuttgart.
Synthesis, antifungal activity and structure-activity relationships of 2-(alkyl or aryl)-2-(alkyl or polyazol-1-ylmethyl)-4-(polyazol-1-ylmethyl)- 1,3-dioxolanes
Baji,Kimny, Tan,Gasquez,Flammang,Compagnon,Delcourt,Mathieu,Viossat,Morgant,Nguyen-Huy
, p. 637 - 650 (2007/10/03)
A series of 2-(alkyl or aryl)-2-(alkyl or polyazol-1-ylmethyl)-4-(polyazol-1-ylmethyl)-1,3-dioxolanes Ia-u was synthesized and tested in vitro against pathogenic fungi in man, animals and plants: Candida albicans, Aspergillus flavus and Fusarium solani. Compounds Iq-t with two polyazol groups have an in vitro activity against these fungi with MIC (minimum inhibitory concentration) value of 5 μg mL-1.
