Hydrogen-free hydrogenation of nitrobenzene <i>via</i> direct coupling with cyclohexanol dehydrogenation over ordered mesoporous MgO/SBA-15 supported Cu nanoparticles
Ravi Kumar Marella, Venkata Rao Madduluri, Sivarama Krishna Lakkaboyana, Marlia M. Hanafiah, Sarala Yaaratha
Abstract
from the dehydrogenation step of the first reactant for the hydrogenation reaction of the second reactant. A catalyst series consisting of four Cu/MgO-SBA15 mesoporous solids with varying Cu loadings (5-20 wt%) were prepared and systematically characterized by BET, ICP, XRD, TPR, TPD, FT-IR, SEM, XPS, and TEM. Among the series, the 15 wt% Cu catalyst exhibited the best performance with ≥82% conversion of nitrobenzene along with ≥89% cyclohexanol conversion. In addition, significantly higher yields of cyclohexanone (83%) and aniline (75%) could be achieved successfully over the same catalyst. Furthermore, the catalyst exhibited almost stable activity during 30 h time-on-stream with slow deactivation. The highly ordered mesoporous silica increases the metal-support interaction with smaller particles of Cu on the surface, and the synergism between acid-base sites is responsible for the improved catalytic activity.