Gas-phase oxidant-free oxidation of cyclohexanol overV₂O₅-MoO₃-M₂O (M = Na, K, Cs) catalysts

43-49Oxidant-free oxidation (dehydrogenation) of cyclohexanol is carried out in a down-flow integral laboratory scale reactor using different alkali doped catalysts. The effect of reaction temperature, contact time (W/F) and doping of alkali metals is studied to check its effect on nature of prominent products of the reaction (cyclohexanone and cyclohexene). At lower temperature the cyclohexanone prevails whereas at higher temperature cyclohexene is observed in prominence. Acid-modified catalysts (with boron and phosphorous) facilitated cyclohexene selectivity whereas alkali modified catalysts facilitated cyclohexanone selectivity. Calcination of sodium modified catalyst at different temperatures under static condition affect characteristic phase intensity and cyclohexanone selectivity. XRD investigation showed formation of different inorganic phases as the characteristic of dopant. Cesium modified catalyst showed better dehydrogenation activity

Alkylation of naphthalene with t-butanol: use of carbon dioxide as solvent

Organic solvent free alkylation of naphthalene and t-butyl alcohol (TBA) over rare earth exchanged Y zeolite (REY) has been carried out in the presence of carbon dioxide at different process conditions (temperature between 418 and 458 K, pressure between 6 and 92 bar, TBA/naphthalene mole ratios of 1:4, and different periods of time (1.5-9 h)). The results suggest that fluid carbon dioxide can replace organic solvents as a medium for butylation of naphthalene over REY without loss of its shape selective characteristics

Barium hexaaluminate nanowhiskers synthesized by novel sol-gel process in reverse micellar media

Barium hexaaluminate (BHA) synthesized by coupling of sol-gel process in reverse microemulsions shows a unique nanowhisker morphology and high surface area, which are retained after calcination at 1300 °C