Hydrogenation and dehydrogenation reactions catalyzed by CNTs supported palladium catalysts

Pd supported on carbon nanotubes (CNTs), Al2O3 and SiO2 were prepared by wet-impregnation method. The synthesized catalysts were characterized by BET, XPS, SEM and TEM. Hydrogenation of benzaldehyde and dehydrogenation of ethylbenzene over Pd/CNTs, Pd/r-Al2O3 and Pd/SiO2 were carried out in fixed bed phase reaction under an atmosphere pressure to test the activity and selectivity of the catalysts. Influence of temperature on activity and selectivity was investigated in both hydrogenation of benzaldehyde and dehydrogenation of ethylbenzene. The selectivity and conversion of obtained products were dependent on the nature of the support and reaction temperature. The Pd/CNTs showed a higher activity (100%) and selectivity to toluene (94.4%) in the hydrogenation. High selectivity (100%) towards the desired the product of styrene was achieved with conversion of ethylbenzene over 45.7% in the dehydrogenation.