Nano Pt/TiO₂ photocatalyst for ultrafast production of sulfamic acid derivatives using 4-nitroacetanilides as...

The design of reactors based on high performance photocatalysts is an important research in catalytic hydrogenation. In this work, modification of titanium dioxide nanoparticles (TiO₂ NPs) was achieved by preparation of Pt/TiO₂ nanocomposites (NCs) through photo-deposition method. Both nanocatalysts were used for the photocatalytic removal of SOx from the flue gas at room temperature in the presence of hydrogen peroxide, water, and nitroacetanilide derivatives under visible light irradiation. In this approach, chemical deSOx was achieved along with protection of the nanocatalyst from sulfur poising through the interaction of the released SOx from SOx-Pt/TiO₂ surface with p-nitroacetanilide derivatives to produce simultaneous aromatic sulfonic acids. Pt/TiO₂ NCs have a bandgap of 2.64 eV in visible light range, which is lower than the bandgap of TiO₂ NPs, whereas TiO₂ NPs have a mean size of 4 nm and a high specific surface area of 226 m²/g. Pt/TiO₂ NCs showed high photocatalytic sulfonation of some phenolic compounds using SO₂ as a sulfonating agent along with the existence of p-nitroactanilide derivatives. The conversion of p-nitroacetanilide followed the combination processes of adsorption and catalytic oxidation-reduction reactions. Construction of an online continuous flow reactor-high-resolution time-of-flight mass spectrometry system had been investigated, realizing real-time and automatic monitoring of completion the reaction. 4-nitroacetanilide derivatives (1a-1e) was converted to its corresponding sulfamic acid derivatives (2a-2e) in 93-99% isolated yields of within 60 s. It is expected to offer a great opportunity for ultrafast detection of pharmacophores.