Direct synthesis of LPG from synthesis gas over Pd–Zn–Cr/Pd-β hybrid catalysts

Abstract

The reaction of synthesis gas to liquefied petroleum gas (LPG) over Zn–Cr-based hybrid catalysts was systematically investigated in this paper. The results show that the synergistic effect, existed in the Zn–Cr-based methanol synthesis component and β zeolite, results in the high performance of hybrid catalysts for synthesis gas to LPG. Active metal Pd in the β zeolite mainly play the role of olefin hydrogenation, which promotes the reaction of the title-mentioned overall reaction. The ratio of SiO 2/Al 2O 3 in Pd-β has a large influence on the stability of hybrid catalysts for syngas to LPG. As the SiO 2/Al 2O 3 ratio increases, CO conversion slightly decreases, however, the catalytic stability of Zn–Cr-based hybrid catalysts is largely improved. The characterization results indicated that during the reaction, the decreasing of acidic sites is the main reason of catalyst deactivation.