Abstract: The structure and catalytic properties of supported Pd/TiO2 and Pd-Ag/TiO2 catalysts for selective hydrogenation of acetylene have been studied by using microreactor tests combined with temperature-programmed reduction (TPR), X-ray diffraction (XRD), infrared spectroscopy of adsorbed carbon monoxide (CO-IR), and electronic paramagnetic resonance (EPR). The results indicate that the Pd/TiO2 catalyst exhibits better catalytic performance than Pd/γ-Al2O3 catalyst for selective hydrogenation of acetylene, which can be correlated to the strong metal-support interaction (SMSI) between Pd and TiO2 in the Pd/TiO2 catalyst. Adding Ag component to Pd/TiO2 catalyst results in formation of Pd-Ag alloy, leading to an increase in selectivity of acetylene hydrogenation to ethylene, but a decrease in the activity of acetylene hydrogenation.

Key words: Pd, Pd-Ag alloy, Titania, Acetylene, Selective catalytic hydrogenation