Synergistic Nanostructured MnO<sub>x</sub>/TiO<sub>2</sub> Catalyst for Highly Selective Synthesis of Aromatic Imines
Putla Sudarsanam, Angela Köckritz, Hanan Atia, Mohamad Hassan Amin, Angelika Brückner
Abstract
Abstract This work reports the development of a synergistic nanostructured MnO x /TiO 2 catalyst, with highly dispersed MnO x nanoparticles (4.5±1 nm) on shape‐controlled TiO 2 nanotubes (8–11 nm width and 120–280 nm length), for selective synthesis of valuable aromatic imines at industrially important conditions. Pristine TiO 2 nanotubes exhibited 97 % imine selectivity at a 38.3 % benzylamine conversion, whereas very low imine selectivity was obtained over commercial TiO 2 materials, indicating the catalytic significance of shape‐controlled TiO 2 nanotubes. The MnO x nanoparticle/TiO 2 nanotube (10 wt% Mn) catalyst calcined at 400 °C showed the best activity with 95.6 % benzylamine conversion and 99.9 % imine selectivity. This catalyst exhibited good recyclability for four times and is effective for converting numerous benzylamines into higher yields of imines. The high catalytic performance of MnO x /TiO 2 nanotubes was attributed to higher number of redox sites (Mn 3+ ), high dispersion of Mn species, and shape‐controlled structure of TiO 2 , indicating that this catalyst could be a promising candidate for selective oxidation reactions.