Thermally decomposed mesoporous Nickel Iron hydrotalcite: an active solid-base catalyst for solvent-free Knoevenagel condensation.

Thermal decomposition of co-precipitated Ni-Fe-HT materials led to the formation a mesoporous Ni-Fe-HT catalyst and we have demonstrated here its active role as solid and active catalyst for the Knoevenagel condensation reaction of various aldehydes with active methylene compounds (R-CH2-CN, where R=CN or CO2Et). High product yields are obtained at moderate temperature under solvent-free conditions and the catalyst can be easily separated from the reaction mixture, simply by filtration and reused several times without a significant loss of its activity. Since these mesoporous metal oxides derived from the NiFe hydrotalcites, their basicity mediated abstraction of the acidic protons from the active methylene compounds was responsible for their catalytic activity under solvent-free conditions.

Calcium oxide supported gold nanoparticles as catalysts for the selective epoxidation of styrene by t-butyl hydroperoxide.

Gold nanoparticles are deposited on basic CaO supports as catalysts for the selective conversion of styrene into styrene oxide. Synthetic methods, gold loading and calcination temperatures are varied to permit an understanding of their influence on gold nanoparticle size, the presence of cationic gold species and the nature of interaction between the gold nanoparticles and the CaO support. Based on these studies, optimal conditions are designed to make the Au/CaO catalyst efficient for the selective epoxidation of styrene.

RP-HPLC Method for Simultaneous Estimation of Nitazoxanide and Ofloxacin in Tablets.

A reverse phase high performance liquid chromatography method was developed for simultaneous estimation of nitazoxanide and ofloxacin in tablet formulation. The separation and quantification was achieved by Hiq Sil C(18)V Size 4.6 mm Ø (*)250 mm column in isocratic mode, with mobile phase consisting of acetonitrile-methanol-0.

Zero order spectrophotometric method for estimation of escitalopram oxalate in tablet formulations.

A new, simple, fast and reliable zero order spectrophotometric method has been developed for determination of Escitalopram Oxalate in bulk and tablet dosage forms. The quantitative determination of drug was carried out using the zero order values (absorbance) measured at 238 nm. Calibration graph constructed at 238 nm was linear in concentration range of 2-20 µg/ml with correlation coefficient 0.

Energy-efficient syngas production through catalytic oxy-methane reforming reactions.

The considerable recent interest in the conversion of stranded methane into transportable liquids as well as fuel cell technology has provided a renewed impetus to the development of efficient processes for the generation of syngas. The production of syngas (CO/H2), a very versatile intermediate, can be the most expensive step in the conversion of methane to value-added liquid fuels. The catalytic oxy reforming of methane, which is an energy-efficient process that can produce syngas at extremely high space-time yields, is discussed in this Review.

A novel route for in-situ H2O2 generation from selective reduction of O2 by hydrazine using heterogeneous Pd catalyst in an aqueous medium.

Hydrogen peroxide in high yields can be generated with high efficiency at mild conditions (25 degrees C and atmospheric pressure) with the formation of only environment-friendly by-products (N2 and H2O) by a reduction of O2 by hydrazine from its hydrate/salt with its complete conversion in a short reaction period ( View Article and Find Full Text PDF

Low-temperature complete combustion of a dilute mixture of methane and propane over transition-metal-doped ZrO2 catalysts: effect of the presence of propane on methane combustion.

Complete combustion of dilute methane alone or a dilute mixture of methane and propane over transition-metal (viz. Mn, Co, Cr, Fe, and Ni)-doped ZrO2 (cubic) catalysts at different temperatures (523-873 K) and a space velocity of 51,000 cm3 x g(-1) x h(-1) has been investigated for controlling methane and propane emissions from exhaust gases. The catalysts are compared for their catalytic ignition temperature and activity in the combustion of propane and methane in the presence of each other.

Drastic increase of selectivity for H2O2 formation in direct oxidation of H2 to H2O2 over supported Pd catalysts due to their bromination.

Incorporation of bromide anions (1.0 wt%) in supported Pd catalysts (viz. Pd supported on Al2O3, ZrO2, SiO2, H-beta or Ga2O3) leads to a drastic increase in their selectivity for H2O2 formation in the direct oxidation of H2 to H2O2 by O2(at room temperature) in an aqueous acidic (0.

Characterization of silicon sites in monoclinic zeolite ZSM-5 using 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) and molecular modelling.

An attempt has been made to correlate the experimentally observed 29Si MAS NMR chemical shifts of monoclinic phase of highly siliceous ZSM-5 with their electronic properties. In order to incorporate the influence of next neighbor atoms on the 29Si chemical shielding of central SiO4, a pentameric cluster model (H12Si5O16) has been chosen. Each of the 24 crystallographically distinct Si sites, of ZSM-5 framework has been modelled by such cluster models.

Low-Temperature Nonoxidative Activation of Methane over H-Galloaluminosilicate (MFI) Zeolite.

Conversion of methane to higher hydrocarbons by its low-temperature activation without forming undesirable carbon oxides is of great scientific and practical importance. Methane can be highly activated, yielding high rates of conversion to higher hydrocarbons and aromatics (10 to 45 percent) at low temperatures (400° to 600°C), by its reaction over H-galloaluminosilicate ZSM-5 type (MFI) zeolite in the presence of alkenes or higher alkanes. The methane activation results from its hydrogen-transfer reaction with alkenes.