Direct synthesis of LPG from syngas over Cu modified FeMg@SiO₂ nano-level core@shell catalyst

Direct synthesis of liquefied petroleum gas from syngas via Fischer-Tropsch synthesis route was systematically investigated over a nano-level core@shell catalyst. We introduced an incorporation of FeMg catalyst into mesoporous silica shell, with a further modification of Cu particles on the silica surface. The modified Cu/FeMg@SiO₂ nano core-shell catalysts were synthesized by the combination of co-precipitation, modified sol-gel and facile impregnation methods. The as-synthesized catalysts’ physicochemical property was characterized by XRD, TEM, N₂ adsorption-desorption, H₂-TPR, XPS and CO₂-TPD techniques. The catalytic performance of Cu/FeMg@SiO₂ catalyst shows a high CO conversion of 96.6%, rather low CO₂ selectivity of 21.9% and considerable LPG selectivity of 37.9%. The catalytic results indicate that the SiO₂ shell restrains the formation of CH₄ and contributes to increasing long-chain products. Meanwhile, the enhanced CO conversion of Cu/FeMg@SiO₂ was ascribed to the active metal Cu dispersed on SiO₂ shell, which also promoted olefin hydrogenation and cracking of C₅₊ hydrocarbons products. The proposed catalyst preparation method will provide a new strategy for the synthesis of nano level catalyst with combinations of metal- and zeolite-based catalyst.