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In recent years, aromatic substances have become the focus of environmental pollution-related concern due to their high stability and mutagenicity. In this regard, researchers have focused their attention on the development of photocatalytic processes to convert nitroaromatic compounds into aniline. In this work, the photocatalytic conversion of nitrobenzene (NB) to aniline (AN) was studied. The photocatalytic reaction was performed using commercial TiO2 (P25) and a photocatalytic aerogel, based on P25 embedded in syndiotactic polystyrene (sPS) aerogel (sPS/P25 aerogel) as photocatalysts. Different alcohols were used as hydrogen sources during the photocatalytic experiments. At the optimized operating conditions (photocatalysts dosage: 0.5 mg/L and 50% (v/v) EtOH%), an AN yield of over 99% was achieved. According to the results, this work could open avenues toward effective production of AN from NB using mild reaction conditions with sPS/P25 aerogel—in view of a possible scale-up of the photocatalytic process.

Ceria-supported vanadium catalysts were studied for H2S removal via partial and selective oxidation reactions at low temperature. The catalysts were characterized by N2 adsorption at 77 K, Raman spectroscopy, X-ray diffraction techniques, and X-ray fluorescence analysis. X-ray diffraction and Raman analysis showed a good dispersion of the V-species on the support. A preliminary screening of these samples was performed at fixed temperature (T = 327 °C) and H2S inlet concentration (10 vol%) in order to study the catalytic performance in terms of H2S conversion and SO2 selectivity. For the catalyst that exhibited the higher removal efficiency of H2S (92%) together with a lower SO2 selectivity (4%), the influence of temperature (307–370 °C), contact time (0.6–1 s), and H2S inlet concentration (6–15 vol%) was investigated.

Heterogeneous photocatalysis in the gas phase has been applied as a promising technique for organic syntheses in mild conditions. Modified zeolites have been used under UV irradiation as novel photocatalysts. In this study, we preliminarily investigated the photoxidation of cyclohexane on ferrierite and MoOx-functionalized ferrierite in a gas&ndash, solid continuous flow reactor. In the presence of UV light, MoOx-functionalized ferrierite showed the formation of benzene and cyclohexene as reaction products, indicating the occurrence of photocatalysed cyclohexane oxydehydrogenation. By contrast, unmodified ammonium ferrierite exhibited relevant activity for total oxidation of cyclohexane to carbon dioxide and water. The influence of Mo loading on cyclohexane conversion and products selectivity was evaluated.

The aim of this work is to demonstrate the effectiveness of the photocatalytic process in the Methyl Orange azo dye degradation and simultaneous H2 production by using ZnO doped with ruthenium. Ru-modified ZnO photocatalysts were prepared by precipitation method and were characterized by different techniques (XRF, Raman, XRD, N2 adsorption at &minus, 196 &deg, C, and UV&ndash, vis DRS). The experiments were carried out in a pyrex cylindrical reactor equipped with a nitrogen distributor device and irradiated by four UV lamps with the main wavelength emission at 365 nm. Different Ru amounts (from 0.10 to 0.50 mol%) were tested in order to establish the optimal amount of the metal to be used for the ZnO doping. The photocatalytic activity was evaluated both in terms of Methyl Orange removal and hydrogen production. The experimental results showed that the best activity, both in terms of H2 production and Methyl Orange degradation, was obtained with the Ru-modified ZnO photocatalyst at 0.25 mol% Ru loading. In particular, after four hours of UV irradiation time, the discoloration and mineralization degree were equal to 83% and 78%, with a simultaneous hydrogen production of 1216 &micro, mol L&minus, 1. This result demonstrates the ability of the photocatalytic process to valorize a dye present in wastewater, managing to obtain a hydrogen production comparable with the data present in the literature today in the presence of other sacrificial substances.