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 β-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+-β-zeolite support is compared with traditional γ-Al2O3-supported catalysts. The Na+-β-zeolite-supported catalysts exhibit higher selectivity than their γ-Al2O3 counterparts. Overall, zeolite-supported Pd–Ag bimetallic catalyst was found to have the highest selectivity of the catalysts studied.