提高USY型FCC催化剂硫转移和催化裂化活性的研究

采用镁、铈、镧和磷对USY型FCC催化剂进行改性，采用FT IR分析方法对改性催化剂的表面酸性进行了表征，研究了硫转移活性组分对催化剂的硫转移和催化裂化活性的影响。结果表明，多次氧化 还原循环后，改性催化剂仍保持较好的硫转移活性，可以达到60%以上。镁的引入会减少基质和分子筛表面强酸的数量，少量镁的引入对催化裂化活性影响不大，铈和镧的引入会使分子筛和基质的表面酸量得到显著增加，提高催化裂化活性，但同时会引起焦炭的增加，磷改性可改善基质和分子筛表面酸性，抑制焦炭的产生，保持催化裂化活性的同时使汽油中的烯烃质量分数下降6%。

Influence of modification of FCC catalyst on its activity and sulfur transfer

The USY FCC catalyst was modified by MgO for changing the matrix structure to improve the performance of sulfur transfer and was modified by Ce2O3, La2O3 and P2O5 for enhancing the activity of sulfur transfer. The properties of modified catalyst were investigated by FT-IR. The effect of MgO, Ce2O3, La2O3 and P2O5 on the activity of sulfur transfer and catalytic cracking reaction were investigated. The result show that the modified catalyst keeps up good activity of sulfur transfer which is kept more than 6% after many times of oxidation-reduction cycle. The introduction of a few MgO decreases the amount of stronger acid on the surface of matrix and zeolite, but does not greatly influence the activity of catalytic cracking reaction. The introduction of rare earth metal increases acid amount of the matrix and zeolite, and promotes catalytic cracking reaction. But high content of rare earth metal also promotes formation of coke. The addition of 1% P2O5 optimizes the acidic properties of the matrix and zeolite to produce the low coke yield. The good activity of catalytic cracking reaction is keot uo while the olefin content in catalytic cracking gasoline is reduced 6 percent.