Journal of Catalysis, Vol.246, No.1, 40-51, 2007
Selective hydrogenation of acetylene in the presence of ethylene on zeolite-supported bimetallic catalysts
Novel catalysts were synthesized by supporting Pd-based bimetallic catalysts on Na+-exchanged beta-zeolites to achieve higher selectivity for the hydrogenation of acetylene in the presence of ethylene at room temperature. Batch reactor studies carried out using infrared spectroscopy show that Pd-Ag bimetallic catalysts have higher selectivity for acetylene hydrogenation in the presence of ethylene than either Pd or Ag monometallic catalysts. Kinetic modeling of the reaction data reveals significant differences in the hydrogenation rate constants and adsorption equilibrium constants. The influence of the Na+-beta-zeolite support is compared with traditional gamma-Al2O3-supported catalysts. the Na+-beta-zeolite-supported catalysts exhibit higher selectivity than their gamma-Al2O3 counterparts. Overall, zeolite-supported Pd-Ag bimetallic catalyst was found to have the highest selectivity of the catalysts studied. (c) 2006 Elsevier Inc. All rights reserved.