pdv改性分子筛催化苯与氢气氧气羟基化反应的研究样本.docxVIP

资料内容仅供您学习参考，如有不当或者侵权，请联系改正或者删除。 Pd-V 改性分子筛催化苯与氢气氧气羟基化反应的研究 化学专业 级 陆庆祝 摘 要 : 在自行设计的一个气体内循环反应装置上 , 研究了 Pd、 Pd-V 、 Pd-Cu 和 Pd-Fe 改性的 Hβ 和 ZSM-5催化剂催化苯与氢氧直接羟基化反应。 结果 表明 : 单 Pd 系列催化剂均能催化苯和氢气、 氧气的羟基化反应 , 但其活性较 低。为了提高催化剂活性 , 我们采用浸渍法制备了 Pd-V、 Pd-Cu 和 Pd-Fe 改性 的 Hβ , 以及 Pd-V/ZSM-5 系列双金属改性催化剂。我们发现对于以 Hβ 沸石为 载体的这类双金属催化剂的催化活性较单钯负载催化剂提高了很多。 这可能是因 为 Pd 促进双氧水的生成 , 而 V、 Cu 和 Fe 又能促进双氧水与苯的反应 , 然而以 ZSM-5为载体的双金属改性催化剂其活性较单钯负载催化剂并没提高多少。 我们 还发现苯酚生成速率在单乙酸介质中较低 , 而添加适量水后则显著增加。 这里我 们提出了一个协同催化作用机理来解释有关过渡金属的改性作用和水的添加效 应。 为了考察催化剂回收的使用活性 , 我们对 0.5 wt%Pd/ZSM-5、 Pd-V/ZSM-5 、 Pd-V/ Hβ、 Pd-Cu/ Hβ 和 Pd-Fe/ Hβ 催化剂进行了回收 , 发现催化剂经过处理后普遍存在失活的现象 , 相对而言 , Pd-Cu/ Hβ 有着较好的回收使用性能。 关键词 : 苯酚 ; 苯羟基化 ; Pd-V/ Hβ ; Pd-V/ZSM-5; Pd/ZSM-5; 浸渍法 Studies on the Pd-V modified zeolite catalysts for the direct liquid hydroxylation of benzene with H 2 and O 2 under the atmosphere QingzhuLu,Grade ,Chemical Education Abstract: A gas inner-circulated apparatus, which was designed by us 资料内容仅供您学习参考，如有不当或者侵权，请联系改正或者删除。 was employed to carry out the direct hydroxylation of benzene with H2 and O2 over Hβ and ZSM-5catalysts modified by Pd; Pd-V; Pd-Cu and Pd-Fe under the atmosphere. The results showed that all the only Pd supported catalysts could catalyze this reaction but their activities were demonstrated relatively low. To improve the activities of catalysts, we had prepared bimetal-modified catalysts such as Pd-V; Pd-Cu and Pd-Fe modified Hβ catalysts, and Pd-V/ZSM-5 by impregnation method. It was found that bimetal-modified Hβ catalysts showed much higher catalytic activity than single Pd modified ones. It can be interpreted that Pd was beneficial to the formation of H O and at the same time V, Cu and Fe were 2 2 helpful to the hydroxylation reaction between H 2O2 and benzene. However, the activity of bimetal-modified catalysts did not be improved much compared to single Pd catalysts when ZSM-5 was used as support. Herein, we also found out that the rate of phenol formation using glacial acid as reaction medium was