Kinetic Parameters For The Selective Hydrogenation Of Acetylene On Gapd2 And Gapd

Intermetallic GaPd2 is a highly selective and stable catalyst for the semi-hydrogenation of acetylene. Knowledge of the underlying reaction kinetics is essential to gain a deeper understanding of the selective hydrogenation on this catalytic material. To date, there has been no experimental kinetic data published for this reaction on a well-defined intermetallic catalyst possessing isolated active sites. Kinetic measurements are performed at 140-200 degrees C, revealing an apparent activation energy of 29(2)kJmol(-1). GaPd2 is shown to be the first binary catalyst material, which shows a positive reaction order (0.89) with respect to acetylene at 200 degrees C. The influences on the extent of acetylene conversion, specific activity and selectivity to ethylene, ethane, and higher hydrocarbons are determined by a 2(4) factorial experiment following a design of experiments approach. Temperature and pressure have the strongest impact on these values. The results allow optimal operation for achieving high ethylene yields. A comparison of the reaction kinetics on GaPd2 with experimental results obtained for GaPd reveals different orders of reaction of H-2 and C2H2 on the two compounds.