Characterization and improvements in the synthesis of the novel solid superacid AlCl2(SG)n

Abstract

The preparation of the novel solid acid catalyst AlC12(SG),, previously synthesized in C C 4 , has been accomplished with a sealed-tube gas-phase reaction using an extended contact time. Reactivity studies and spectroscopic investigations indicate the similarity in the catalysts prepared via the two different methods. The hydration level of the silica support, prior to use in catalyst synthesis, is examined in this work. Excessively dry silica is deficient in surface silanol (Si-OH) moieties and yields an ineffective catalyst. Exposure of this dry silica to humid air allows sufficient hydration for the preparation of an active catalyst. Calorimetric titration and spectral studies show that the Bronsted acidity of the solid gives rise to its strong acidity.

Oxyfunctionalization of n-pentane and n-hexane by oxovanadium complexes supported on carbamated modified silica gel

“…The modified silica gel was prepared by the reaction of the above filtrate containing phenyl isocyanate (20 mL) with the silanol groups on the surface [35] of silica gel (2.0 g). The mixture was stirred at 40 8C for 6 h and the solid (carbamated modified silica gel) was filtered off and washed with dry benzene.…”

Low Temperature Direct Conversion of Methane using a Solid Superacid

“…ABZ‐5 was prepared as follows: H‐ZSM‐5 was prepared by calcining NH 4 ‐ZSM‐5 at 500 °C for 3 h in a muffle furnace. In order to optimize the −OH concentration on the surface of the as‐prepared H‐ZSM‐5, it was washed in three alternate cycles of HBr (1 M) and deionized water and then dried in a vacuum at 80 °C for 72 h before being exposed to the room atmosphere …”

Oxidation of n-heptane with molecular oxygen using heterogeneous catalyst formed by covalently binding [1,2-bis(salicylidene amino)-phenylene] zirconium complex to modified silica gel

“…This was then refluxed with 50 ml of HCl (35%) in a flask for 4 h and the hydroxylated silica gel [20] was separated and washed with distilled water several times. Phenyl isocyanate (as confirmed by its IR and 13 CNMR) was prepared by the reaction of sodium azide (35 g, 0.538 g mol), with an equivalent number of moles of benzoyl chloride (76 g, 0.54 g mol) in dry benzene medium (20 ml) at 0 • C with constant stirring.…”