Abstract: Direct synthesis of liquefied petroleum gas (LPG) from syngas over hybrid catalysts consisting of methanol synthesis catalyst and Pd-modified zeolites such as Pd/SAPO-11, Pd/ZSM-5, Pd/β, and Pd/Y was investigated in a fixed-bed reactor. Pore diameter of zeolites had great effect on LPG selectivity. The hybrid catalyst composed of methanol synthesis catalyst and Pd/Y demonstrated a good reactivity and more than 73% selectivity for LPG at 300 ^oC, 2.1 MPa, and the space velocity of 1 500 h^-1. N₂ adsorption-desorption, NH₃ temperature-programmed desorption and temperature-programmed oxidation were carried out to study the properties of the catalysts before and after reaction. The results indicated that coke deposition was the main reason for the catalyst deactivation.

Key words: syngas, liquefied petroleum gas, hybrid catalyst, Y-zeolite, coke deposition