Synthesis of palladium nanocatalysts on the base of silica gel for selective hydrogenation of phenyl acetylene

Abstract

Pd/SiO2 catalysts containing 4,0 and 9,1 wt.% were synthesized. Their characterization by electron microscopy revealed nano-size of Pd particles (1,70±0,72 and 1,30±0,64, respectively). The effect of Pd content and conditions of precursor (Pd acetate) reduction on the catalytic properties of Pd/SiO2 samples in the reaction of selective hydrogenation of phenyl acetylene (PA) to styrene (S) at 25 °C was studied. Increase of both Pd content (from 4,0 to 9,1 wt.%) and temperature (from 50 to 120 °C) was shown not to lead to substantial enlargement of Pd particles and, as a consequence, on the rate and selectivity of PA hydrogenation. It was found that nano-sized Pd/SiO2 systems are the efficient catalysts for industrially important process of PA hydrogentation demonstrating high selectivity to S (96,75 and 90,3 % at conversion values of 50 and 100 %, respectively), which exceed substantially the reported values (75 % at complete conversion).