The design of a CZ@H-beta-P catalyst with core shell structure and its application in LPG synthesis from syngas

Liquefied petroleum gas (LPG, C3 and C4 paraffins) from syngas have attracted much attention recently due to the growing demand of non-oil resource as well as its environmentally friendly features, but the catalytic reaction process controlled by thermodynamics and CO conversion rate is low with many side reactions. Here we report a catalyst with core shell structure for LPG synthesis from syngas. Zeolite as shell was synthesized by hydrothermal method firstly and then coated on Cu/ZnO core with Ludox (CZ@Z), the Cu/ZnO core was prepared by co-precipitation method. The unique core shell structure had efficient synergistic effect. The reaction equilibrium favored forward reaction because methanol as an intermediate was directly transformed to dimethyl ether. The zeolite type in the core shell structure catalyst had great effects on the activity and selectivity. The catalysts have been characterized by XRD, NH3-TPD and SEM. The activities were determined after in situ H-2 reduction. CZ@H-beta catalyst showed a more effective catalytic activity compared with the traditional hybrid catalyst. The excellent catalytic performance was attributed to the combined contribution of both unique core shell structure and proper zeolite type. At these reaction conditions, temperature of 350 degrees C, pressure of 3.0 MPa and flow rate of 40 ml min(-1), CO conversion and hydrocarbons selectivity achieved 61.8% and 64.2%, respectively. LPG selectivity in hydrocarbons was 70.2%.