Structured silica reactor with aligned carbon nanotubes as catalyst support for liquid-phase reaction

Scaling up and macronization of carbone nanomaterials open a new era for their industrial applications. Here we report the synthesis of aligned and strongly attached multi-walled carbon nanotubes on the wall of a silica reactor, which can be efficiently used as a catalyst support in liquid-phase reactions. The electronic microscopy (SEM and MEB) analysis techniques were used to characterize the morphology and the microstructure of the as-synthesized catalyst support. The probe reaction used was the liquid-phase hydrogenation of a CC bond using palladium as an active phase. The great advantage of using such a structured reactor was the avoidance of catalyst-product separation which is generally encountered with liquid-phase reactions and the high reactant-active phase contact surface due to the nanoscopic size of the support.

Graphical abstractThe synthesis of aligned (B) and strongly attached multi-walled carbon nanotubes on the wall of a silica reactor, which can be efficiently used as a catalyst support in liquid-phase reactions was executed. The CNTs/SiO2 tube (C) was directly used as mechanical stirrer in the selective hydrogenation of cinnamaldehyde using palladium as an active phase (A). The selectivity towards the hydrocinnamaldehyde, i.e. CC bond hydrogenation, remained high and constant regardless of the level of conversion, i.e. selectivity of 90% at a conversion of about 80%.Figure optionsDownload full-size imageDownload as PowerPoint slide