PREPARATION OF BIMETALLIC PD-FE AL2O3 CATALYSTS BY UNDERPOTENTIAL DEPOSITION OF IRON/

Bimetallic Pd-Fe/Al2O3 catalysts were prepared by underpotential depos ition (UPD) of iron on parent Pd/Al2O3 catalysts of varying dispersion . Tile potential of palladium particles was controlled by the suppleme ntary redox system H+/H-2. Iron introduced by this method improves the activity of small palladium particles for the hydrogenation of isopre ne in the liquid phase. An explanation of this phenomenon would be a s elective deposit of iron on or near the palladium sites of low coordin ation. However, the promoting effect of iron disappears after exposure of bimetallic catalysts to air and subsequent reduction.