Mohan Dongare - Academia.edu (original) (raw)

Papers by Mohan Dongare

Arkivoc, Jun 18, 2002

A variety of amines react with Boc 2 O in the presence of a catalytic amount of yttria-zirconia b... more A variety of amines react with Boc 2 O in the presence of a catalytic amount of yttria-zirconia based catalyst to afford the corresponding N-Boc products in excellent yields.

Synlett, Dec 31, 2001

letter, Synlett 2001; 2001(2): 0206-0209 DOI: 10.1055/s-2001-10778. © Georg Thieme Verlag, Rüdige... more letter, Synlett 2001; 2001(2): 0206-0209 DOI: 10.1055/s-2001-10778. © Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published ...

Journal of Molecular Catalysis A-chemical, Mar 25, 2002

... of Isotopes, Hungary, with He as the carrier gas, a flow rate of 50 ml min −1 , and a heating... more ... of Isotopes, Hungary, with He as the carrier gas, a flow rate of 50 ml min −1 , and a heating rate of 10 K min −1 from room temperature to 625 °C; NH 3 ... We are grateful to Dr. MK Gurjar, Head, Organic Chemistry: Technology division for his constant encouragement and support. ...

Catalysis Communications, Feb 1, 2002

Phenol is selectively nitrated in liquid phase to ortho-nitrophenol in high yield using dilute ni... more Phenol is selectively nitrated in liquid phase to ortho-nitrophenol in high yield using dilute nitric acid over solid acid catalysts. Zeolite H-beta was found to be a very active catalyst for nitration of phenol to ortho-nitrophenol at room temperature in carbon tetrachloride as a solvent. Compared to the conventional process, phenol nitration over solid acid catalyst is a clean and environment friendly process with a simpler workup procedure for quantitative isolation of the products.

Catalysis Today, Dec 1, 1999

H-AITS-1 zeolite with Si/Ti = 50 and Si/Al = 50 was employed in preparing catalyst samples by ion... more H-AITS-1 zeolite with Si/Ti = 50 and Si/Al = 50 was employed in preparing catalyst samples by ion-exchange and impregnation with a copper nitrate solution to obtain 0.24-1.15 wt.% and 1.5, 2 and 2.5 wt.% Cu loading, respectively. The catalytic properties for the NO decomposition were compared with that of Cu-ZSM-5 (Si/Al = 25 with 2 wt.% Cu loading) and similarity was found between the AITS-1 based samples and Cu-ZSM-5. Due to the higher acidity, the activity at 500 • C per total copper atoms (an apparent turnover frequency, TOF) was significantly higher over Cu based AITS-1 samples being 2-3 × 10 −3 s −1 as compared to 1 × 10 −3 s −1 measured on Cu-ZSM-5. For the ion-exchanged Cu-AITS-1 there was an increase in TOF with increasing copper content, whereas on the impregnated samples a decrease in TOF was found. On all catalysts there was a maximum in the NO conversion at 500-550 • C. The amount of NO per copper atom measured by temperature programmed desorption (TPD) was about the same as that on Cu-ZSM-5 and the features of the TPD were also similar. At the first contact of the catalyst at 500 • C with the 2 vol% NO/Ar gas a transient N 2 O formation and a considerable delay in the O 2 formation was observed. This could, however, be reproduced only on fresh catalyst, while all further transients showed different but reproducible features using the same sample.

Materials Chemistry and Physics, May 1, 2004

... Permissions & Reprints. Preparation and photo-catalytic activity of Fe---TiO 2 thin films... more ... Permissions & Reprints. Preparation and photo-catalytic activity of Fe---TiO 2 thin films prepared by solgel dip coating. ... Abstract. Thin films of iron (Fe) doped titanium dioxide (Fe---TiO 2 ) were prepared on a variety of substrates by using Ti-peroxy solgel dip coating method. ...

Journal of Molecular Catalysis A-chemical, 2006

Thin films of Au/TiO2 on glass substrates have been prepared by simple solgel dip coating method... more Thin films of Au/TiO2 on glass substrates have been prepared by simple solgel dip coating method using a sol of colloidal gold doped titanium peroxide (Au/TiO2 sol). The sol of colloidal gold and titanium peroxide forms a viscous gel after 13h depending on the ...

Bulletin of Materials Science, Dec 1, 1988

The deintercalation properties of layered oxide Ko.67CoO 2 with H20 have been investigated with r... more The deintercalation properties of layered oxide Ko.67CoO 2 with H20 have been investigated with respect to topotactic solvation and exchange processes. The layered oxide Ko.67 CoO 2 forms hydrated phases and undergoes K+/H + exchange resulting in the formation of a new Ko.l 5 Ho.s5 CoO2 compound. Thermal behaviour of these compounds has been investigated.

Journal of Catalysis, Feb 15, 2004

A series of NiO–ZrO2 samples with 2 to 40 mol% of NiO were prepared using a sol–gel synthesis tec... more A series of NiO–ZrO2 samples with 2 to 40 mol% of NiO were prepared using a sol–gel synthesis technique and calcined at 873 K. XRD characterization of the samples revealed the stabilization of a cubic zirconia- (fluorite) phase containing nickel oxide up to 20 mol%. Bulk NiO characteristics were observed above 20 mol% loading of NiO. The linear decrease in lattice parameter up to 20 mol% of NiO indicates

Green Chemistry, 2006

Nitration of benzene has been carried out in the vapor phase, using dilute nitric acid as the nit... more Nitration of benzene has been carried out in the vapor phase, using dilute nitric acid as the nitrating agent, over mesoporous MoO3/SiO2 solid acid catalyst with more than 90% benzene conversion and 99.9% selectivity for mononitrobenzene. A series of MoO3/SiO2 catalysts with varying MoO3 loadings (1–30 mol%) were prepared using a sol–gel technique and characterized using X-ray diffraction analysis (XRD), BET specific surface area analysis, temperature-programmed desorption (TPD) of ammonia, and FTIR spectroscopic analysis of adsorbed pyridine. XRD analysis revealed the amorphous nature of the catalyst for 1 and 10 mol% MoO3 loading, and the formation of a crystalline α-MoO3 phase on the amorphous silica support at higher MoO3 loading. The BET surface area for pure silica support was 606 m2 g−1 and the pore size distribution in the range 40–80 A, showing the mesoporous nature of amorphous silica. The BET surface area decreased to 583 m2 g−1 with incorporation of 1% MoO3 and further decreased to 180 m2 g−1 with increasing MoO3 loading up to 20%. Above 10% MoO3 loading, formation of crystalline MoO3 clusters on amorphous silica was observed. Ammonia-TPD showed a drastic increase in acid strength after addition of 1% MoO3 compared to pure silica support and the acid strength increased with increasing MoO3 content. Among the series of catalysts prepared, MoO3/SiO2 containing 20 mol% MoO3 was found to be the most active catalyst for benzene nitration, without showing any deactivation after more than 1000 h, showing a very high potential for commercialization.

Thermochimica Acta, Aug 1, 1982

The thermal decomposition of Al(OPr'),, Ca(OEt), and Mg(OEt), has been studted usmg differential ... more The thermal decomposition of Al(OPr'),, Ca(OEt), and Mg(OEt), has been studted usmg differential thermal analysts and thermogravimetric techmques. The decomposnion products have been isolated and identified by gas chromatography and mass spectrometry. Probable routes for the thermal decomposition of these alkoxtdes have been proposed * NCL Communication No. 2943.

The formation of silane (SiH.) has been observed during the reaction of silicon tetrachoride and ... more The formation of silane (SiH.) has been observed during the reaction of silicon tetrachoride and hydrogen (SiC!. + H,) with magnesium silicide (Mg2Si) at 400-500°C. The silane formed decomposes to give silicon in the vicinity of Mg,Si charge. A mixture of trichlorosilane + H2 reacts with Mg2Si at 250°C to afford silane which has been separated and decomposed to high purity silicon. The reaction of SiHCI] + H2 with Mg,Si gives optimum conversion when SiHCI,:H, ratio is 1:4 at the reaction temperature of 250°C.

Oriental journal of chemistry, Apr 22, 2008

Hydrogenation is a class of reductive chemical reactions in which the net result is an addition o... more Hydrogenation is a class of reductive chemical reactions in which the net result is an addition of hydrogen (H 2). Targets of hydrogenation are often alkenes or imine. Most hydrogenations involve the direct addition of diatomic hydrogen under pressure, often in practice with catalysts. Some hydrogenations involve the indirect addition of hydrogen, these are called transfer hydrogenations. The classical example of a hydrogenation is the addition of hydrogen on unsaturated bonds between carbon atoms, converting alkenes to

ChemInform, Mar 7, 1989

Journal of environmental analytical chemistry, 2015

ratio of 1:8, catalyst amount of 10.5% of the total weight of reactants, 6 hr reaction time and r... more ratio of 1:8, catalyst amount of 10.5% of the total weight of reactants, 6 hr reaction time and reaction temperature was 120°C [15].

Catalysis Communications, Oct 1, 2007

Antimicrobial drug, tinidazole has been synthesized by condensation of 2-methyl,5-nitro-imidazole... more 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.

Journal of Materials Science, 1984

The preparation of stabilized zirconia by thermal decomposition of metal alkoxides is reported. F... more The preparation of stabilized zirconia by thermal decomposition of metal alkoxides is reported. Formation of stabilized zirconia takes place at 400 ~ C. The a.c. conductivity of the samples has been measured from 400 to 1000 ~ C. The best conductivity is found in ZrO2 doped with 15 per cent CaO, which at 400 ~ C is 2.37 • 10-6 gZ-1 cm-1 and at 1000~ C is 1.26 x 10-2 D,-1 cm-1, with an activation energy of 1.16 eV. Transport number measurements show that stabilized zirconia prepared by this method is purely an oxygen ion conductor.

Chemistry – An Asian Journal

Hydrogenation of phenol to cyclohexanone/cyclohexanol is an important reaction in production of n... more Hydrogenation of phenol to cyclohexanone/cyclohexanol is an important reaction in production of nylon‐6, nylon‐66 and in petroleum industry. Liquid phase phenol hydrogenation over Pd‐CuO/CeO2 was carried out under mild conditions. Palladium impregnated over CuO/CeO2 synthesized by co‐precipitation method showed excellent catalytic activity for phenol hydrogenation (99% conversion with 80% cyclohexanol yield) at 90 °C and 10 bar H2 pressure in water. Commercial 10%Pd/C showed only 8% phenol conversion under identical conditions. The detailed characterization revealed significant improvement in surface area of ceria after addition of CuO and decrease in crystallite size with creation of defects in CeO2 lattice. XPS analysis showed Pd loading on CuO/CeO2 to cause hydrogen spillover on the surface leading to increase in the oxygen vacancies. The interaction of phenol with catalyst surface studied by detailed FTIR analysis, revealed activation of phenol on oxygen vacancy of ceria as phen...