| The production of liquid fuel from coal via syngas through Fischer-Tropsch synthesis is of great significance based on the energy framework of abundance in coal and scarce in crude oil reserve of our country. Iron-based catalyst due to its high F-T activity, low cost as well as high water-gas-shift(WGS)activity, is more preferable for F-T process of coal-derived syngas ,which has low H2/CO ratio. Moreover, the addition of promoters and supports can optimize F-T performance of iron-based catalyst to some extent.And K, Cu, SiO2 are the common promoters. Before F-T synthesis reactions, CO and/or H2 should be adsobed on surface of catalysts first, and then several actived species are formed following its activation. So adsorption of CO and/or H2 on catalyst surface have great effect on F-T activity and selectivity.In present, study is carried out to investigate the effect of SiO2,Cu,K on CO and/or H2 adsorption based on predecessors work. A series of catalysts with different SiO2 contents,different Cu contents and different K contents ,were prepared by the combination of co-precipitation. The textual properties and crystal phases were studied by N2 physisorption and X-ray diffraction (XRD), respectively. Differential thermal/thermogravimetric analysis(TG/DTG) and temperature-programmed reduction(TPR) were used to characterizate reduction performances of catalysts with differeent promoters and supports. The effect of promoters and supports on CO and H2 adsorption were investigate by H2/CO-TPD. And the experimantal results could beconcluded as follows:1,Effect of SiO2 on H2/CO Adsorption for F-T synthesis iron-based catalystsH2 adsorption of catalysts incorporated with SiO2 decreased because reductionand carburization were suppressed. With different pretreatments in H2 or CO, different actived species were formed which made a difference in CO adsorption. What's more, SiO2 promoter could stablize Fe3C phase and made variation of CO adsorption with great regularity. After pretreatments in CO, CO adsorption is stranger than H2 adsorption in syngas. The present of CO have greater effect on H2 adsorption while present of H2 have no effect on CO adsorption.2,Effect of Cu on H2/CO Adsorption for F-T synthesis iron-based catalystsReduction and carburization were faciled with catalysts added with Cu which increase H2 adsorption both pretreatments in H2 and CO. After pretreatments in H2,several actived species are formed on catalysts and several CO adsorption appeared in accordance. What's more, Cu promoter could stablize Fe5C2 phase which effect CO adsorption. After pretreatments in CO, prescent of Cu could not change the case that CO adsorption is stranger than H2 adsorption in syngas, but effect the COadsorption.3,Effect of K on H2/CO Adsorption for F-T synthesis iron-based catalystsCatalysts promoted with K have greater H2 adsorption after pretreaments in CO but lower after pretreaments in H2. What's more, after pretreaments in CO, catalysts promoted with K have lower CO adsorption compared with catalyst free of K. For competitive adsorption in syngas, catalysts promoted with K have greater H2 and CO adsorption.
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