Vapor-phase Nitration of Benzene over Silica-supported Benzenesulfonic Acid Catalyst

Abstract

Silica-supported benzenesulfonic acid has a high catalyst activity for the title reaction. A nitrobenzene yield on benzene basis and on nitrogen dioxide basis attained to 93% and 70%, respectively, at 443 K under partial pressures of benzene and nitrogen dioxide of 9.3 kPa and 19 kPa, respectively.

Characterization, adsorption and photocatalytic activity of vanadium-doped TiO2 and sulfated TiO2 (rutile) catalysts: Degradation of methylene blue dye

“…Several attempts have been made to improve the photoefficiency of anatase titania by adding adsorbents like silica, alumina, zeolites, clays, and active carbon [8][9][10][11][12][13]. This is expected to induce synergism because of the adsorption properties of the adsorbents with respect to organic molecules.…”

Studies on para‐selectivity and yield enhancement in zeolite catalyzed toluene nitration

“…1994) and Fe, B, and Ti substituted versions (Salakhutdinov et al, 1993), sulphonated ion exchange polystyrene resins (Wright et al, 1965), perfluorinated sulphonic acid (Olah et al, 1978), clay supported metal nitrates (Laszlo and Vondormeal, 1988;Delaude et al, 1993), Fe 3þ on K10 Montmorillonite (Choudary et al, 1994), modified silica (Smith, 1989), modified silica-alumina, and supported acid (Kameo et al, 1974;Schubert and Wunder, 1978;Suzuki et al, 1987;Riego et al, 1996) versions have been reported. Conventional nitrating agents like nitric acid alone or in combination with acetic anhydride, mixed acids, nitrogendioxide (Radoslaw and Smallridge, 2001), acyl nitrates (benzoyl and acetyl), and alkyl nitrates continue to engage the attention of some researchers (Olah et al, 1989) which resulted in achieving improved para-selectivity (defined as the molar ratio of para-and ortho-nitrotoluenes) although their commercial viability is questionable.…”

Chemical modification of high-quality large-pore M41S materials

“…Silica catalysts impregnated with benzenesulfonic acid are, for example, good catalysts in the gas phase nitration of benzene. 16 In liquidphase systems, the benzenesulfonic acid might be less stable due to the reversibility of the sulfonation under certain chemical conditions. Nevertheless, due to the variety of different substitution reactions with the grafted phenyl group these materials offer many other possibilities for further derivatisation besides sulfonation.…”