Ce助剂对Pt-Sn/Ce-γ-Al2O3催化剂长链烷烃(n-C16～20)脱氢反应性能的影响

摘要

A series of Pt-Sn/Ce-γ-Al2O3 catalysts with different Ce contents was prepared by vacuum impregnation method and characterized by XRD, CO-chemisorption, H2-TPR, TG and NH3-TPD. The effect of Ce promoter on the structure and catalytic properties of Pt-Sn/Ce-γ-Al2O3 catalysts for the dehydrogenation of long chain paraffins n-C16-20 was investigated. The results showed that the addition of cerium modified the acidity of the catalysts, and changed the reducibility of the catalysts due to the strong interactions among Pt,Sn,Ce and supports. It also promoted the reduction of platinum oxide,improved the thermal stability of Pt particles, inhibited the reduction of SnOx species and decreased the coke formation. The addition of cerium could greatly enhanced the activity and stability of Pt-Sn/Ce-γ-Al2O3 catalyst.%采用真空浸渍法制备了不同Ce含量的Pt-Sn/Ce-γ-Al2O3催化剂,采用X射线衍射、CO脉冲吸附、程序升温还原、热重及氨程序升温脱附等手段对催化剂进行表征,研究Ce助剂对Pt-Sn/Ce-γ-Al2O3催化剂结构及其催化长链烷烃(n-C16～20)临氢脱氢反应性能的影响.结果表明,Ce的引入可以调变催化剂酸性,改变催化剂的还原性能；Pt、Sn和Ce以及载体之间产生较强的相互作用能够促进氧化铂的还原,提高铂粒子的热稳定性,抑制锡物种还原,降低催化剂积炭,有利于提高催化剂的脱氢活性及稳定性.