Characterization and performance of Pd/Ni(Zn)-aluminate catalysts for acetylene hydrogenation

0.03 wt% Pd catalysts on nickel and zinc aluminate supports were prepared by impregnation. The samples were characterized by XRD, BET, ICP, SEM, EDS, CO-TPD, NH3-TPD, and their performances were evaluated in an acetylene selective hydrogenation reaction. The Ni2Al18O29, NiAl26O40 and NiAl2O4 structures for nickel aluminates and ZnAl2O4 and Zn4Al22O37 structures for zinc aluminates were identified in supports. The specific surface area of aluminateswere in the range of 46.7-87.5 m(2)/g. Surface acidity of the support was in the order nickel aluminate < zinc aluminate < theta, delta-alumina. CO-TPD analysis showed that most of Pd active sites on the aluminate support were in multicoordination forms. The nickel and zinc aluminates had lower acetylene conversion than theta and delta alumina.