SO_4^(2-)促进型多元氧化物超强酸催化剂上丁烷异构化反应

Butane Isomerization on SO_4^(2-) Promoted Mixed Oxide Superacid Catalysts

考察了一系列SO促进型多元氧化物超强酸催化剂的正丁烷异构化反应性能．在ZrO2中添加Ni、Fe、Cr、Mn和V等第二和第三组份金属元素可有效地提高催化剂在氮气气氛下的异构化活性，但催化剂活性下降很快．改成氢气气氛可使部分多元氧化物催化剂的积炭速度减缓，进一步提高活性和稳定性．载铂对提高SO／ZrO2催化剂的活性和稳定性是有效的，但对多元氧化物催化剂无积极作用．在临氢反应过程中，添加的金属元素价态未发生变化，催化剂的稳定性与积炭量相对应，烧炭以后初活性可完全恢复，积炭可能是造成催化剂迅速失活的主要原因．

Butane isomerization was catalyzed by a series 0f SO promoted mixed oxide superacid catalysts. Incorporation of Ni, Fe, Mn, or V into ZrO2 as a second or third metal component may enhance the isomerization activity of the catalysts under N2 atmosphere, but the catalyst deactivation is rapid. Change to H2 atmosphere can slow the coke formation and improve the activity and selectivity of some mixed oxide catalysts. Supporting Pt is of advantage for enhancing the activity and selectivity of SO ZrO2, but it does not work for the mixed oxide catalysts. In the c0urse of reaction under atmosphere, the valence states of incorpordted metal components are unaltered as examined by XPS. The amount of coke deposited on the catalysts is related t0 their stability, and their initial activities are completely recovered after burning off the coke. Coking is probably the main reason for rapid catalyst deactivation.