Effect of Resorcinol Formaldehyde Resin Gel on the Preparation of Co/SiO2 Catalysts for Fischer-Tropsch Synthesis

Highly loaded Co/SiO2 catalysts were prepared by the co-precipitation method with resorcinol formaldehyde resin gel (RFG). Most RFG was decomposed during the drying process at 393 K, and little carbon was remained in the catalysts. However, the presence of RFG during the precipitation played the important roles in increasing the pore sizes of catalysts and the reducibility and dispersion of supported cobalt, leading to the more surface active cobalt sites and large pores of the catalysts and therefore the higher activity for the Fischer-Tropsch reactions to produce heavy hydrocarbons. The catalyst 80%Co/SiO2-C thus prepared was as active and selective as the 80%Co-8%ZrO2/SiO2 (an excellent catalyst reported previously) for the synthesis of heavy hydrocarbons from syngas. 采用共沉淀法制备了高 Co 含量的 Co/SiO2 费托合成催化剂, 并向其中添加一定含量的间苯二酚-甲醛树脂凝胶. 结果表明, 催化剂在 393 K 干燥时, 树脂会发生分解, 因而仅有少量的含碳凝胶残留在催化剂中. 然而, 少量碳凝胶的存在显著增加了催化剂的还原度和金属钴的分散度, 致使催化剂表面产生更多的活性金属 Co, 同时, 催化剂的孔径也有所增大, 因此 Co/SiO2 催化剂具有更高的反应活性及高碳烃选择性. 其中 80%Co/SiO2-C 催化剂活性及高碳烃的选择性与我们前期报道的一种高活性的 80%Co-8%ZrO2/SiO2 催化剂相近.