A series of highly dispersed Pd/Al2O3 catalysts were prepared via the polyol method. The catalysts were characterized by nitrogen adsorption, X-ray diffraction (XRD), UV-Vis spectrophotometry, temperature programmed reduction (TPR) and transmission electron microscopy (TEM). The influence of Pd particle size on the hydrogenation of 2-amyl anthraquinone (AAQ) was investigated in a trickle-bed reactor. The turnover frequency (TOF) showed antipathetic size dependence while the space time yield (STY) peaked at 4 nm. Also, the selectivity and deactivation rate were affected by the size of palladium particles. The structure-sensitivity relations for the catalysts may be ascribed to the necessities of specific Pd cluster structure for the activation of π-bond.
Keywords:
anthraquinone hydrogenation; H2O2; dispersion
