助剂Cu、K对F-T合成铁基催化剂作用的表征研究

A series of spherical micron-scale Fe-based catalysts, in which K and Cu promoters are incorporated respectively or simultaneously, are prepared by a combination method of continuous co-precipitation and spray drying technology. The textural properties, reduction performance, phase transformation in reduction and/or carbonization process are studied by means of low temperature N2 adsorption, MES, XRD, H2-TPR, CO-TPR and constant temperature reduction in H2, CO and syngas environment. The results indicate that the addition of K promoter can increase the surface area of Fe-based catalyst and iron species dispersion in catalyst, and reinforce the interaction between Fe2O3 and silica. The addition of Cu promoter improves the reduction of catalyst and the formation of Fe3O4 phase in H2 and syngas environment, but Cu promoter favors the formation and stabilization of a-Fe phase in CO environment. The addition of K promoter only will suppress the reduction and/or carbonization of catalyst in H2-containous environment, but the simultaneous addition of K and Cu promoters can apparently enhance the reduction and/or carbonization in H2, CO and syngas environment, which shows the synergic effect of Cu and K promoters.