@article { ISI:000256183700015, title = {Phosphotungstic acid on silica with modified acid sites as a solid catalyst for selective cleavage of tert-butyldimethylsilyl ethers}, journal = {Catalysis Communications}, volume = {9}, number = {9}, year = {2008}, month = {MAY}, pages = {1863-1868}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The strength and nature of acid sites of bulk phosphotungstic acid could be modified after dispersing it on silica support which was characterized by XRD, ammonia TPD and (31)P MAS NMR techniques. This solid acid catalyst was found to be highly selective for the cleavage of tert-butyldimethylsilyl ethers at room temperature. The catalyst was easily recovered by filtration and could be reused for several times without loss of any activity giving a TON of 9.5 x 10(5). (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Ammonia TPD, Catalytic cleavage, reaction pathway, solid acid, tert-butyldimethylsilyl ethers, XRD}, issn = {1566-7367}, doi = {10.1016/j.catcom.2008.03.017}, author = {Bhure, Mahesh H. and Kumar, Indresh and Natu, Arun D. and Chikate, Rajeev C. and Rode, Chandrashekhar V.} } @article { ISI:000269426900019, title = {Acetalization of glycerol using mesoporous MoO3/SiO2 solid acid catalyst}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {310}, number = {1-2}, year = {2009}, month = {SEP}, pages = {150-158}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Acetalization of glycerol with various aldehydes has been carried out using mesoporous MoO3/SiO2 as a solid acid catalyst. A series of MoO3/SiO2 catalysts with varying MoO3 loadings(1-20 mol\%) were prepared by sol-gel technique using ethyl silicate-40 and ammonium heptamolybdate as silica and molybdenum source respectively. The sol-gel derived samples were calcined at 500 degrees C and characterized using various physicochemical characterization techniques. The XRD of the calcined samples showed the formation of amorphous phase up to 10 mol\% MoO3 loading and at higher loading of crystalline alpha-MoO3 on amorphous silica support. TEM analyses of the materials showed the uniform distribution of MoO3 nanoparticles on amorphous silica support. Raman spectroscopy showed the formation of silicomolybdic acid at low Mo loading and a mixture of alpha-MoO3 and polymolybdate species at high Mo loadings. Moreover the Raman spectra of intermediate loading samples also suggest the presence of beta-MoO3. Acetalization of glycerol with benzaldehyde was carried out using series of MoO3/SiO2 catalysts with varying MoO3 loadings (1-20 mol\%). Among the series, MoO3/SiO2 With 20 mol\% MoO3 loadings was found to be the most active catalyst in acetalization under mild conditions. Maximum conversion of benzaldehyde (72\%) was obtained in 8 h at 100 degrees C with 60\% selectivity for the six-membered acetal using 20\% MoO3/SiO2. Interestingly with substituted benzaldehydes under same reaction conditions the conversion of aldehydes decreased with increase in selectivity for six-membered acetals. These results indicate the potential of this catalyst for the acetalization of glycerol for an environmentally benign process. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Acetalization, Aldehyde, Glycerol, Silicomolybdic acid, solid acid}, issn = {1381-1169}, doi = {10.1016/j.molcata.2009.06.010}, author = {Shubhangi B. Umbarkar and Kotbagi, Trupti V. and Biradar, Ankush V. and Pasricha, Renu and Chanale, Jyoti and Dongare, Mohan K. and Mamede, Anne-Sophie and Lancelot, Christine and Payen, Edmond} } @article { ISI:000286902200016, title = {One-pot synthesis of 2,4,5-trisubstituted imidazoles using MoO3/SiO2, an efficient and recyclable catalyst}, journal = {Synthetic Communications}, volume = {41}, number = {5}, year = {2011}, month = {JAN}, pages = {PII 932996516}, publisher = {TAYLOR \& FRANCIS INC}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

[image omitted] A simple one-pot synthesis has been developed for the synthesis of 2,4,5-trisubstituted imidazoles using an efficient and recyclable MoO3/SiO2 solid acid catalyst by condensation of benzil or benzoin, benzaldehyde, and ammonium acetate in acetonitrile as a solvent. Using this solid catalyst, the reactions could be carried out under mild reaction conditions with very good yield of imidazoles, up to 95\%. This catalyst could be recycled very easily, which makes this methodology environmentally benign.

}, keywords = {benzil, benzoin, cyclocondensation, imidazoles, MoO3, One-pot, SiO2, solid acid}, issn = {0039-7911}, doi = {10.1080/00397911003644415}, author = {Bhosale, Sidhanath V. and Kalyankar, Mohan B. and Nalage, Santosh V. and Bhosale, Dattatry S. and Pandhare, Swati L. and Kotbagi, Trupti V. and Shubhangi B. Umbarkar and Dongare, Mohan K.} } @article {47091, title = {Sulfonic acid-functionalized heterogeneous catalytic materials for efficient biodiesel production: a review}, journal = {Journal of Environmental Chemical Engineering}, volume = {9}, year = {2021}, month = {FEB}, pages = {104719}, type = {Review}, abstract = {

The development of social productive forces leads to the increasing consumption of fossil fuels. However, the burning of traditional fossil fuels releases huge amounts of carbon emissions into the atmosphere, resulting in drastically increased global surface temperatures, and hence, global warming and abnormal climate change. Biodiesel, which can be produced by (trans)esterification of bio-oils using solid acid catalysts, is recognized as renewable and clean energy, alternative to fossil-derived diesel, and it can meet society{\textquoteright}s requirements. This review describes the catalytic conversion of bio-derived oils into biodiesel using various sulfonic acid-functionalized heterogeneous catalytic materials that show higher catalytic efficiency and superior recyclability. Besides, various methods of biodiesel preparation and the appropriate design and preparation of robust and efficient catalytic materials for biodiesel production were provided. Finally, the mechanisms of different catalytic esterification and transesterification reactions for biodiesel synthesis, the relevant reaction kinetic models, and techno-economic analysis of biodiesel production were critically discussed in this review.

}, keywords = {(Trans)esterification, Biodiesel, heterogeneous catalysis, kinetic study, solid acid}, doi = {10.1016/j.jece.2020.104719}, author = {Tan, Xiang and Sudarsanam, Putla and Tan, Jinyu and Wang, Anping and Zhang, Heng and Li, Hu and Yang, Song} } @article {48933, title = {Novel sulfonic acid functionalized silica supported isonicotinic acid catalyst for conversion of 2-methylfuran to diesel fuel precursors}, journal = {Catalysis Letters}, volume = {154}, year = {2024}, month = {APR}, pages = {1511-1520}, type = {Article}, abstract = {

Polyfuranic compounds produced after carbon up-gradation of 2-methylfuran by acid catalyzed C-C bond forming reactions when undergo hydro-deoxygenation produce diesel fuel. Herein, we prepared a simple and novel silica supported sulfonic acid functionalized isonicotinic acid SO3H-INA@SiO2 catalyst by treating isonicotinic acid with chlorosulphonic acid followed by heterogenization on silica. This heterogeneous solid acid catalyst was explored for the solvent free conversion of 2-methylfuran to diesel fuel precursors of C-15 and C-20 units via tandem ring opening followed by condensation sequence. Under optimized reaction conditions, SO3H-INA@SiO2 was able to convert, 2-methylfuran completely into condensation products such as 5,5-bis(5-methylfuran-2-yl)pentan-2-one (1) and 2,4,4-tris(5-methylfuran-2-yl)pentan-1-ol (2) with 19\% and 67\% yields, respectively. The heterogeneous SO3H-INA@SiO2 catalyst was successfully recycled up to six consecutive runs without loss of its activity. The SO3H-INA@SiO2 catalyst offered superior activity as compared to the commercially available -SO3H functionalized resins. Superior activity of the prepared catalyst could be attributed for its higher acidity, smaller particle size and high surface area. Structure of the prepared catalyst was confirmed by FTIR and solid state NMR. Total acidity of the prepared catalyst was determined by acid-base titration.

}, keywords = {2-Methylfuran, Diesel fuel, heterogeneous catalyst, Ionic solid, solid acid}, issn = {1011-372X}, doi = {10.1007/s10562-023-04383-2}, author = {Tarade, Komal P. and Kamble, Sanjay P. and Rode, Chandrashekhar V.} } @article {49223, title = {Selective synthesis of renewable diesel fuel precursors via C-C condensation of biomass-derived furans using a niobium oxide nanocatalyst}, journal = {ACS SUSTAINABLE CHEMISTRY \& ENGINEERING}, volume = {12}, year = {2024}, month = {SEP }, pages = {15923-15934}, type = {Journal Article}, keywords = {2-Methylfuran, Catalysts, dehydration, NB2O5, RANGE ALKANES, solid acid, Valorization}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.4c03886}, author = {Kumar, Mudavath Arun and Swapna, Bhattu and Kalbande, Pavan Narayan and Yalagandula, Lavanya and Singh, Satyapaul A. and Sudarsanam, Putla} }