Improvement of Pd/Al2O3 catalyst performance in selective acetylene hydrogenation using mixed phases Al2O3 support

The catalytic performances of Pd catalysts supported on γ-Al2O3, α-Al2O3, and mixed phases Al2O3 were investigated in the selective hydrogenation of acetylene in ethylene feed stream. It was found that the use of mixed phases Al2O3 with approximately 64% of α-phase resulted in significant improvements in both acetylene conversion and ethylene selectivity. The presence of small amount of transition phase in the alumina supports brought about higher BET surface area and Pd dispersion as well as improvement of reduction ability of the Pd/Al2O3 catalysts. On the other hand, significant amount of α-Al2O3 is necessary for high ethylene selectivity due to the lower amount of ethylene adsorbed.