Cu、Ni、Ru、Pt对费托合成Fe催化剂的助剂作用研究

考察了Cu、Ni、Ru、Pt对费托合成Fe催化剂的助剂作用。XRD结果表明,加入Cu、Ni助剂对催化剂有一定的分散作用,而Ru、Pt影响不大。XPS结果表明,所有添加的助剂在催化剂表面均有一定程度的富集,且4种过渡金属助剂与Fe存在不同程度的电荷相互作用。H₂-TPR表明,Cu、Pt、Ru在催化剂还原过程中首先还原为金属态,进而能够明显促进催化剂的还原。CO-TPD表明,加入Cu、Pt、Ni助剂对CO的吸附活化有明显的促进作用。用固定床反应器对催化剂的费托反应性能进行了评价,反应结果表明,加入Ru、Ni、Pt、Cu会依次提高催化剂的反应活性,Pt、Cu、Ru、Ni助剂会依次使催化剂的CH₄选择性增加,并降低C₅₊的选择性。

Promoting effects of Cu,Ni, Ru and Pt on Fe-based catalysts in Fischer-Tropsch

The promoting effects of Cu, Ni, Ru and Pt on Fe-based catalysts in Fischer-Tropsch Synthesis were investigated. XRD results indicated that both Cu and Ni can enhance the dispersion of fresh catalysts. XPS results showed that all these metal promoters are enriched on the catalyst surface, whereas four promoters are different in their electronic interaction strength with Fe. H₂-TPR results suggested that Cu, Ru and Pt can be reduced at first to corresponding metal species, which can then promote the reduction of Fe₂O₃ to Fe₃O₄ significantly; however, the influence of Ni on catalyst reduction is of less significance. CO-TPD results illustrated that the addition of the Cu, Pt and Ni can improve the adsorption of CO on the catalysts. The performances of these catalysts in Fischer-Tropsch synthesis was evaluated in a fixed-bed reactor, which indicated that the activity of CO hydrogenation is enhanced through the addition of these metal promoters; the activity of related catalysts follows the order of Fe3Cu > Fe3Pt > Fe3Ni > Fe3Ru > Fe, whereas the selectivity to CH₄ increases in the order of Fe3Ni > Fe3Ru > Fe3Cu > Fe3Pt > Fe.