Na-Fe/C催化剂的设计及其CO加氢制烯烃性能OA

Fischer-Tropsch synthesis(FTS)is a process that converts synthesis gas into clean liquid fuels and high-value chemicals through heterogeneous catalytic reactions.In it,rational design of the structure of Fe-based catalysts can achieve the directional conversion of synthesis gas to high-value olefins.A carbon support was prepared using a sucrose solution as the carbon source;the texture and surface properties of the carbon sup-port were adjusted through pyrolysis reactions;C-loaded Fe-based catalysts were prepared,and Na promoter was used to modify the catalyst surface;the influence of the catalyst surface properties on FTS performance was investigated.The results indicate that 600℃is the optimal pyrolysis reaction temperature,and the C-600 sup-port prepared at this temperature possesses abundant oxygen-containing groups,high specific surface area,and suitable pore structure.The introduction of the support significantly promotes metal dispersion;the oxygen-containing groups are conducive to improving olefin selectivity and carbon chain growth ability;the addition of Na increases the electron cloud density of the Fe sites due to the electron transfer effect,thereby enhancing the catalyst's ability to adsorb and dissociate CO,promoting the carbon chain growth of catalytic reaction products,and inhibiting hydrogenation side reactions;when the mass fraction of Na modification is 2％,the catalytic per-formance is optimal,with a CO conversion of 86.76％,a C2-C4=selectivity of 41.92％,an olefin to paraffin molar ratio(O/P)of 5.68,and a linear α-olefin selectivity of 66.31％of the total hydrocarbons,effectively optimizing the product distribution.The research results can provide insights into the design of high efficiency Fe-based catalysts.