Selective photo-oxidation of benzene over transition metal-exchanged BEA zeolite
Selective photo-oxidation of benzene over transition metal-exchanged BEA zeolite
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过渡金属交换 BEA 沸石上苯的选择性光氧化
DOI：
10.1016/j.apcata.2004.04.001
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发表时间：
2004
影响因子：
5.5
通讯作者：
Y. Kitayama
中科院分区：
文献类型：
--
作者：
Ken;H. Akahane;T. Kodama;Y. Kitayama
在室温下，以分子氧为氧源，研究了分散在C6 H6/CH 3CN/H2O混合溶剂中的阳离子交换沸石对液态苯的选择性光氧化反应。用11种过渡金属阳离子交换的沸石进行了筛选。Pd ~（2+）、Fe ~（3+）和Cu ~（2+）对苯酚（对苯二酚、间苯二酚、邻苯二酚和苯酚）的生成有促进作用。在Pd ~（2+）、Fe ~（3+）和Cu ~（2+）催化剂上主要生成苯二酚类化合物，而在TiO_2半导体（Degussa P25）催化剂上主要生成苯酚和CO_2。Pd（NH3）4负载后，其光催化性能发生了很大的变化，在均相溶液中，Pd 2 +-Pd（NH3）4] Cl 2对苯酚类化合物的生成具有更高的活性和选择性，其上苯的非选择性光氧化为CO2是主要反应。24小时内Pd 2 +-BEA生成酚类的转化数为35（以Pd计），表明反应具有催化作用。
Selective photo-oxidation of liquid benzene was studied using cation-exchanged zeolites dispersed in C6H6/CH3CN/H2O mixture at room temperature by using molecular oxygen. Screening with BEA zeolites exchanged with 11 kinds of transition metal cations was performed. Pd2+-, Fe3+- and Cu2+-BEA were shown to be effective for the formation of phenols (hydroquinone, resorcinol, catechol and phenol). The dihydroxybenzenes were mainly produced on Pd2+-, Fe3+- and Cu2+-BEA, while phenol and CO2were the main products on TiO2semiconductor (Degussa P25). The photocatalytic property was greatly changed by immobilization of Pd2+on BEA; Pd2+-BEA showed higher activity and selectivity for the formation of phenols than [Pd(NH3)4]Cl2in homogeneous solution, on which unselective photo-oxidation of benzene to CO2was the main reaction. The turnover number of Pd2+-BEA for the formation of phenols was 35 (based on Pd) in 24h, indicating that the reaction proceeded catalytically.