催化剂酸碱性对异丙醇脱水活性的影响

The Study of Synergism of Acid and Base Centers in Catalytic Dehydration for Propanol-[2]

研究了具有不同酸碱中心的催化剂对异丙醇脱水反应活性及选择性的影响,结果表明:催化剂表面有合适的酸碱强度和H_(o),max值,能引起高的脱水活性和选择性。红外吸附态证实:在接近反应状态下,催化剂表面出现了—CH2结构吸附,这表明反应物的碱基(OH基)与催化剂表面酸中心作用的同时,酸基(反应物的β-H)与催化剂表面碱作用,催化剂上这种酸碱活性中心协同作用结果使异丙醇脱水生成丙烯的过程很可能以协同机理方式进行。

Based on the experimental results of IR detection of the absorbed species and effect of acid-base strength on the catalytic properties,it is shown that the activity and selectivity for catalytic dehydration of propanol-[2] are high at an appropriate acid, and basic strength and a H0,max value. The existance of an adsorbed species (-CH_(2)) on catalyst surface verified by IR measurement, means that the reaction takes place by interactions between OH groups of propanol-[2] and acid centers of the given catalyst surface and between H groups ofβ-C in the reactant and base centers of catalyst.It is possible that the acid-base center synergism enables the given reaction to taske place.