大肠杆菌为模板制备Au@TiO_2催化剂及其CO氧化反应活性  

Preparation of Au@TiO_2 Catalyst Using Escherichia Coil as the Template and Its Oxidation Reaction Activity toward CO

作　　者：刘玉良[1] 由翠荣[1] 李杨[1] 何涛[1] 张香芹[1] 索掌怀[1] 

机构地区：[1]烟台大学化学生物理工学院,山东烟台264005

出　　处：《物理化学学报》2010年第9期2455-2460,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20473070;20973148)资助项目~~

摘　　要：许多微生物对金属离子有较强的吸附还原能力.本文利用大肠杆菌(DH5α)对金属离子较强的吸附与还原能力制备了Au@DH5α,再利用大肠杆菌的水分来水解钛酸四丁酯,得到Au@DH5α-Ti(OH)4样品,焙烧去除大肠杆菌后得到氧化钛包裹的纳米金粒子催化剂Au@TiO2.以N2吸附,X射线衍射(XRD),紫外-可见漫反射光谱(UV-VisDRS),热重-差热分析(TG-DTA),透射电镜(TEM)对所得材料进行表征.结果表明:该催化剂具有与大肠杆菌类似的杆状结构,以大肠杆菌为生物模板生成的氧化钛孔道结构在一定程度上抑制了金粒子的聚集长大.随菌体用量的增加,金粒子减小,等离子共振吸收发生紫移,催化剂有较大的比表面积,但催化剂中积炭量也会增加.将该催化剂用于CO氧化反应,发现当菌体用量为100或150mL时,制得的金催化剂可在80℃下将CO完全氧化为CO2.Many microorganisms can adsorb metal ions strongly and even reduce them to their metal states.We studied the adsorption of gold nanoparticles on Escherichia coil（DH5α） to form Au@DH5α.Titanium tetrabutoxide was added to Au@DH5α to prepare Au@DH5α-Ti（OH）4 by hydrolysis.The DH5α template was removed by calcination in air to obtain the Au@TiO2 catalyst.These materials were characterized by N2 adsorption,X-ray diffraction（XRD）,UV-Vis diffuse reflectance spectroscopy（UV-Vis DRS）,thermogravimetry-differential thermal analysis（TG-DTA）,and transmission electron microscopy（TEM）.The results show that the gold catalyst maintains a rod-like structure similar to DH5α and the porous structure of the titanium oxide prepared using DH5α as a biological template can prevent the aggregation of gold nanoparticles to some extent.With higher amounts of DH5α dosage,smaller gold nanoparticles were obtained and the surface plasmon absorption of gold nanoparticles shifted toward shorter wavelengths.The obtained gold catalyst has a larger surface area than the catalyst prepared by the impregnation method.However,this increases the coke content of the catalyst.Catalytic activity was evaluated by the CO oxidation reaction.We found that with a DH5α dosage of 100 or 150 mL,the obtained gold catalyst can convert CO to CO2 completely at 80℃.

关 键 词：二氧化钛 大肠杆菌 模板剂 金催化剂 CO氧化 

分 类 号：O643.36[理学—物理化学]