Influence of KOH modification on TiO2 structure and Au/TiO2 catalyst activity in CO oxidation
-
摘要: 以不同浓度KOH处理钛酸丁酯水解产物得到KOH改性TiO2载体。使用N2吸附、热重-差热分析-示差扫描量热、X射线粉末衍射、紫外可见漫反射光谱、透射电镜及X射线光电子能谱研究了KOH对TiO2结构、形貌的影响。结果表明，较低浓度的KOH对TiO2有较显著的改性效果，改变了TiO2的电子结构。对KOH-TiO2负载的金催化剂，K的给电子作用有利于金维持其零价态，从而提高催化剂的CO氧化反应活性。但KOH浓度过高，使载体孔道堵塞，吸附能力减弱，导致金粒子发生团聚，分散性变差，活性下降Abstract: KOH-modified TiO2 support was obtained by treating the hydrolysate of tetrabutyl titanate with KOH solution of various concentrations; the gold catalyst supported on the KOH-modified TiO2 was prepared through impregnation and used for CO oxidation. The support and catalyst were characterized by N2 physical sorption, thermogravimetry, thermo-analysis, X-ray powder diffraction, UV-vis diffuse reflection spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicate that the modification with KOH may influence the structure and property of TiO2 and Au/TiO2 significantly. KOH modification can change electronic structure of TiO2 and enhance the activity of Au/TiO2 catalyst for low-temperature CO oxidation. However, the modification with excessive KOH may also block the porous structure of TiO2 and weaken its adsorption ability, which leads an enlargement of gold particles on Au/TiO2 and a decrease of its catalytic activity for CO oxidation.
-
点击查看大图
计量
- 文章访问数: 1635
- HTML全文浏览量: 12
- PDF下载量: 1014
- 被引次数: 0
下载:
