Cu助剂对聚乙烯醇辅助沉淀铁催化剂费托合成反应性能的影响

通过共沉淀法或聚乙烯醇（PVA）辅助共沉淀法分别制备了Fe₂O₃和FeCu催化剂，结合BET、XRD、SEM、H₂-TPR等表征手段，研究了Cu助剂对PVA辅助的沉淀铁催化剂的织构性质、物相结构、形貌特征、还原行为以及F-T合成反应性能的影响。结果表明，Cu助剂的加入增大了铁基催化剂中α-Fe₂O₃的晶粒，减小了催化剂的BET比表面积和孔容，增大了孔径；改变了铁基催化剂的形貌；促进了铁基催化剂在H₂中的还原。反应过程中，在催化剂中只添加Cu助剂时，有利于提高催化剂的反应活性，而当同时加入Cu助剂和PVA时，由于Cu助剂与PVA较强的相互作用，反而降低了催化剂的反应活性，且催化剂的选择性向轻质烃方向偏移。

Effect of Cu promoter on polyvinyl alcohol-assisted preparation of iron catalyst for Fischer-Tropsch synthesis

Fe₂O₃ or FeCu catalysts were prepared by co-precipitation method with or without the assistance of polyvinyl alcohol (PVA). The effect of Cu promoter on the structure and catalytic behaviour of the catalysts were investigated. The catalysts were characterized by BET, SEM, XRD, H₂-TPR and FT-IR techniques. The results showed that the addition of Cu promoter could enhance the crystal growth of α-Fe₂O₃, decrease BET surface area and pore volume and increase pore size and promote the reduction of the catalysts in H₂. In addition, Cu promoter remarkably influenced the surface morphology. In Fischer-Tropsch synthesis (FTS) reaction, the catalytic activity was increased when Cu promoter was added only. The addition of Cu promoter and PVA decreased the FTS activity, and shifted the hydrocarbon products to lighter molecular weight.