Effects of calcium ions on solubility and aggregation behavior of an anionic sulfonate gemini surfactant in aqueous solutions

In this work, a ternary composite, Pt/TiO(2)/RGO (reduced graphite oxide), was prepared via immobilizing Pt particles onto the TiO(2)/RGO composite that was obtained via redox reaction of TiCl(3) and GO. The composite was characterized by different techniques including X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The TiO(2) particles with size less than 10 nm were uniformly distributed throughout the RGO, and almost each Pt particle with size around 3 nm adhered to TiO(2) particles, resulting in high dispersion of all Pt particles on the support. The Pt particles were in the electron-deficient state due to the strong interactions with the TiO(2) particles and the RGO support. The catalytic performance of the composite for nitrobenzene hydrogenation was investigated under solvent-free condition. It was indicated that the Pt/TiO(2)/RGO catalyst exhibited high activity with a turnover frequency (e.g., 59,000 h(-1)) as well as superior selectivity to aniline (e.g., >99%). Moreover, the catalyst can be reused for six times without any activity loss, which resulted from the stable structure of the catalyst.