@article { ISI:000237725100015, title = {Regioselective nitration of cumene to 4-nitro cumene using nitric acid over solid acid catalyst}, journal = {Catalysis Communications}, volume = {7}, number = {6}, year = {2006}, month = {JUN}, pages = {394-398}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The regioselective nitration of cumene to 4-nitro cumene (4-NC) has been carried out using 70\% nitric acid over MoO3/SiO2 solid acid catalyst with high conversion (62\%) and selectivity (68\%) for 4-NC. A series of MoO3/SiO2 catalysts with different MoO3 loadings (1-20 mol\%) were prepared by sol-gel technique and characterized using different characterization techniques. XRD analysis revealed the amorphous nature of the catalyst up to 10-mol\% MoO3 loading and formation of alpha-MoO3 crystalline phase on amorphous high surface area mesoporous silica support at higher MoO3 loading. Maximum conversion and selectivity has been obtained with slower addition of nitric acid and simultaneous azeotropic removal of water formed during the reaction. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {cumene, nitration, ring nitration, side chain nitration, solid acid catalyst}, issn = {1566-7367}, doi = {10.1016/j.catcom.2005.12.022}, author = {Mathew, Sanyo M. and Biradar, Ankush V. and Shubhangi B. Umbarkar and Dongare, Mohan K.} } @article { ISI:000250026200021, title = {Synthesis of tinidazole by condensation-oxidation sequence using MoO3/SiO2 bifunctional catalyst}, journal = {Catalysis Communications}, volume = {8}, number = {10}, year = {2007}, month = {OCT}, pages = {1550-1555}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Antimicrobial drug, tinidazole has been synthesized by condensation of 2-methyl,5-nitro-imidazole and 2-ethyl-thio-ethanol over MoO3/SiO2 catalyst to obtain 1-(2-ethyl-thio-ethanol)-2-methyl-5-nitro-imidazole which is further oxidized using hydrogen peroxide using the same MoO3/SiO2 catalyst to obtain tinidazole. MoO3/SiO2 catalyst (20\%), synthesized by sol-gel process showed the highest acid strength and was successfully demonstrated to catalyze both condensation and oxidation in the synthesis of tinidazole. Due to the bifunctional activity of the catalyst, the use of acetic acid for condensation step and tungstic acid or ammonium molybdate for oxidation step in the conventional synthesis of tinidazole could be eliminated, thus making it an environmentally benign process. The catalysts could be recycled five times without any appreciable loss in the conversion and selectivity showing the potential for. the use of MoO3/SiO2 as bifunctional catalyst for the production of this industrially important compound. (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {antimicrobial drug, condensation, MoO3/SiO2, Oxidation, solid acid catalyst, tinidazole}, issn = {1566-7367}, doi = {10.1016/j.catcom.2007.01.001}, author = {Chandorkar, J. G. and Shubhangi B. Umbarkar and Rode, C. V. and Kotwal, V. B. and Dongare, Mohan K.} } @article { ISI:000256183700006, title = {Sulfamic acid: an efficient and cost-effective solid acid catalyst for the synthesis of alpha-aminophosphonates at ambient temperature}, journal = {Catalysis Communications}, volume = {9}, number = {9}, year = {2008}, month = {MAY}, pages = {1822-1826}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Sulfamic acid catalyzed solvent-free protocol has been developed for the synthesis of alpha-aminophosphonates by three component condensation between aldehydes, amines and diethyl phosphite at ambient temperature. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {alpha-Aminophosphonates, diethylphosphite (DEP), solid acid catalyst, Solvent-free, sulfamic acid (SA)}, issn = {1566-7367}, doi = {10.1016/j.catcom.2008.02.011}, author = {Mitragotri, Satish D. and Pore, D. M. and Desai, Uday V. and Wadgaonkar, P. P.} } @article { ISI:000293491600007, title = {Esterification of fatty acids with glycerol over Fe-Zn double-metal cyanide catalyst}, journal = {Catalysis Communications}, volume = {12}, number = {14}, year = {2011}, month = {AUG}, pages = {1302-1306}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Solid Fe-Zn double-metal cyanide (DMC) complex exhibits high catalytic activity for esterification of fatty acids (FA) with glycerol. DMC catalysts with varying acidities were prepared by synthesizing the material at four different temperatures (10, 25, 50 and 80 degrees C). The catalyst prepared at 50 degrees C exhibited highest catalytic activity. Catalytic activity of DMC was influenced by both acidity and surface area. Complete conversion of FA was achieved at 140-200 degrees C under atmospheric pressure. Chain length of FA was found to influence the rate of reaction and product selectivity. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Acid-catalyzed reaction, Double-metal cyanide (DMC), Esterification of fatty acid, Fatty acid glycerides, solid acid catalyst}, issn = {1566-7367}, doi = {10.1016/j.catcom.2011.05.008}, author = {Kotwal, Mehejabeen and Deshpande, Suvarna S. and Srinivas, D.} } @article { ISI:000286856600053, title = {Hydrolysis of vegetable oils and fats to fatty acids over solid acid catalysts}, journal = {Applied Catalysis A-General}, volume = {391}, number = {1-2, SI}, year = {2011}, month = {JAN}, pages = {427-435}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Solid Fe-Zn double-metal cyanide (DMC) complexes exhibit high catalytic activity for hydrolysis of edible and non-edible vegetable oils and animal fat. In a batch reaction, complete conversion of vegetable oil triglycerides to fatty acids with selectivity greater than 73 wt\% was obtained at temperatures as low as 463 K, autogenous pressure and with 5 wt\% of catalyst. Catalytic activity of DMC was superior to Amberlyst (TM) 70, SAPO-11, H-beta, HY, MoO(x)/Al(2)O(3) and sulfated zirconia. Rates of hydrolysis were greatly enhanced when solvents (tetrahydrofuran or N,N-dimethylformamide), phase transfer agents (tetrapropyl ammonium bromide) and products (a mixture of mono-/diglycerides and fatty acids) or fatty acid was added to the feed. Surface hydrophobicity which enables high wettability and activation of glycerides on active, acidic sites of reusable DMC is attributed to be the major cause for its superior catalytic activity. (C) 2010 Elsevier B.V. All rights reserved.

}, keywords = {Double-metal cyanide complex, Fat splitting, Fatty acids, Hydrolysis of vegetable oils and fats, solid acid catalyst}, issn = {0926-860X}, doi = {10.1016/j.apcata.2010.03.047}, author = {Satyarthi, J. K. and Srinivas, D. and Ratnasamy, P.} } @article { ISI:000334895800008, title = {Value addition to lignocellulosics and biomass-derived sugars: an insight into solid acid-based catalytic methods}, journal = {Journal of Chemical Sciences}, volume = {126}, number = {2, SI}, year = {2014}, note = {21st National Symposium on Catalysis (CATSYMP), CSIR Indian Inst Chem Technol, Hyderabad, INDIA, FEB 11-13, 2013}, month = {MAR}, pages = {373-385}, publisher = {Catalysis Soc India}, type = {Article, Proceedings Paper}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

For the synthesis of important platform chemicals such as sugars (xylose and arabinose) and furans (furfural and 5-hydroxymethylfurfural (HMF)) from carbohydrates (hemicellulose and fructose) solid acid catalysts are employed. Similarly, over solid acid catalysts, conversion of lignin into aromatic monomers is performed. It is observed that in the dehydration of fructose, because of higher hydrothermal stability, silicoaluminophosphate (SAPO) catalysts give better activity (78\% HMF yield) compared with other solid acid catalysts (\<63\% HMF yield) at 175 degrees C. Particularly, SAPO-44 catalyst can be reused at least 5 times with marginal decrease in the activity. Zeolite, BUSY (Si/Al = 15) is active in the conversion of isolated (pure) hemicellulose to produce 41\% C-5 sugars in water. The catalyst is also active in the selective conversion of hemicellulose from bagasse to yield 59\% C-5 sugars. It is possible to obtain high yields of furfural (54\%) directly from bagasse if instead of water, Water+toluene solvent system is used. Depolymerization of lignin using HUSY catalyst produced aromatic monomers with 60\% yield at 250 degrees C. A detailed catalyst characterization study is performed to understand the correlation between catalyst activity and morphology. To understand the effect of impurities present in the substrate over solid acid catalysts, metal-exchange study is carried out.

}, keywords = {aromatic monomers, Biomass, furans, Hemicellulose, lignin, solid acid catalyst}, issn = {0974-3626}, author = {Bhaumik, Prasenjit and Deepa, Ayillath K. and Kane, Tanushree and Dhepe, Paresh Laxmikant} } @article { ISI:000370664300002, title = {Solid acid catalyzed synthesis of furans from carbohydrates}, journal = {Catalysis Reviews-Science and Engineering}, volume = {58}, number = {1}, year = {2016}, month = {JAN}, pages = {36-112}, publisher = {TAYLOR \& FRANCIS INC}, type = {Article}, address = {530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA}, abstract = {

The alternative feedstock, biomass (particularly lignocelluloses), having the profuse availability, is promising for the synthesis of several value-added chemicals which are currently obtained from fossil feedstock. In this article, the synthesis of two extremely significant furan chemicals viz. furfural and 5-hydroxymethylfurfural (HMF) are discussed. In the synthesis of furans from biomass, numerous challenges, i.e., use of edible sugars as substrates, selectivity to furans, their isolation in pure form, reuse of catalyst, environmental issues, etc., are perceived and in the recent past researchers tried to resolve those by developing advance methodologies. This article comprehensively summarizes the latest progress made in the above-mentioned areas and also provides commentary on the analyses of results, rationale for observed activity and mechanisms, etc. It also discusses future aspects of this work.

}, keywords = {Biomass conversion, carbohydrates, cellulose, furans, furfural, hemicelluloses, HMF, solid acid catalyst}, issn = {0161-4940}, doi = {10.1080/01614940.2015.1099894}, author = {Bhaumik, Prasenjit and Dhepe, Paresh Laxmikant} } @article {46411, title = {Altering the O/C ratio of lignin derived monomers without sacrificing atom efficiency}, journal = {ChemistrySelect}, volume = {4}, year = {2019}, month = {DEC}, pages = {14050-14055}, type = {Article}, abstract = {

Synthesis of platform and fuel grade chemicals from lignin without losing atom efficiency and lowering O/C ratio is a challenge in a bio-refinery concept. In this work, we report solid acid catalysed alkylation of lignin derived variety of monomers such as guaiacol, veretrole, phenol, anisole, and catechol using numerous alcohols as alkylating agents. Results elaborate that the type of acidity and structure of catalyst play important role in achieving higher dialkylated products (DAP). With 85\% conversion of guaiacol, 30.9\% DAP formation was achieved at 250 degrees C within 2 h. A unique substrate adsorption study on the catalyst surface and effect of solubility of substrates on the activity of catalyst is evaluated. Catalyst was observed to be recyclable with marginal loss in the activity due to handling error.

}, keywords = {Alcohols, Alkylation, lignin, Monomers, solid acid catalyst, Up-gradation}, issn = {2365-6549}, doi = {10.1002/slct.201903320}, author = {Singh, Dheerendra and Dhepe, Paresh L.} } @article {46928, title = {Synthesis and characterization of supported heteropoly acid: efficient solid acid catalyst for glycerol esterification to produce biofuel additives}, journal = {Inorganic and Nano-Metal Chemistry}, volume = {50}, year = {2020}, month = {NOV }, pages = {1157-1165}, type = {Article}, abstract = {

Esterification of glycerol with acetic acid has been studied with different solid acid catalysts, prepared by impregnating phospotungustic, silicotungstic, and phosphomolybdic acids on polymeric material polyvinylpyrrolidone. These results were compared with commercially available montmorillonite KSFO catalyst showed that PVP-DTP gave higher selectivity to di- and triacetins. This study was mainly focused on increasing the selectivity toward triacetin which is an excellent alternative to fossil fuel based fuel additives. The detail characterization was done for the PVP-DTP catalyst which gave complete conversion of glycerol and maximum selectivity of 34\% toward triacetin. Complete conversion of glycerol was achieved at 110 degrees C within 6 h of reaction time. The characterization of the catalyst was performed by SEM/EDX, X-ray diffraction, thermogravimetic techniques, and FT-IR analysis.TPD-NH3 characterization showed that DTP supported on PVP increases the catalyst acidity of PVP. The highest acidity of PVP-DTP is also confirmed using NH3-TPD analysis.

}, keywords = {Glycerol, phospostugustic acid, povidone, solid acid catalyst, triacetin}, issn = {2470-1556}, doi = {10.1080/24701556.2020.1737817, Early Access Date = MAR 2020}, author = {Magar, Subhash and Mohanraj, Govindraj T. and Jana, Sumit Kumar and Rode, V, Chandrashekhar} }