Preparation of Highly Dispersed Anchored Catalysts by Photochemical Activation of Adsorbed Species and Their Photocatalytic Activities

吸附物质光化学活化制备高分散锚定催化剂及其光催化活性

基本信息

批准号：
62550595
负责人：
ANPO Masakazu
金额：
$ 1.28万
依托单位：
University of Osaka Prefecture
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

Photochemical activation of various transition metal compounds adsorbed on innert support surfaces is expected to be a promising method to prepare highly dispersed welldefined catalysts. In this research, the advantage of this method to prepare the highly dispersed anchored oxide catalysts and their photocatalytic activities have been investigated for the systems of TiCl_4, MoCl_5, and VoCl_3 adsorbed on porous Vycor glass.Especially, highly dispersed anchored vanadium oxide catalysts have been first prepared by using facile reaction of the photochemically activated VoCl_3 molecules with surface OH groups on Vycor glass. Anchored vanadium oxides prepared by the prepsent photochemical method exhibit a higher activity for the photocatalytic isomerization reaction of 2-butene and much higher yields in the phosphorescence, as compared with those obtained for the vanadium oxides prepared by conventional impregnation method. A good linear relationship between the yields of photocatalytic isomerization and the yields of phosphorescence from the charge transfer excited triplet state of the surface vanadyl species in tetrahedral coordination is obtained, indicating that not only the surface vanadyl species paly a significant role in the photocatalytic reaction on vanadium oxide catalysts, but also a photochemical activation method of adsorbed compounds leads to the higher photocatalytic activity due to their higher dispersion of metal oxides than impregnation method.

吸附在内载体表面上的各种过渡金属化合物的光化学活化有望成为制备高度分散的明确催化剂的有前途的方法。本研究以多孔Vycor玻璃吸附的TiCl_4、MoCl_5和VoCl_3体系为研究对象,研究了该方法制备高分散锚定氧化物催化剂的优势及其光催化活性。首先通过光化学活化的 VoCl_3 分子与 Vycor 玻璃表面 OH 基团的轻松反应制备。与传统浸渍法制备的钒氧化物相比，通过本发明的光化学方法制备的锚定钒氧化物对2-丁烯的光催化异构化反应表现出更高的活性，并且在磷光中表现出更高的产率。光催化异构化产率与四面体配位表面氧钒物种的电荷转移激发三重态磷光产率之间存在良好的线性关系，表明不仅表面氧钒物种在光催化反应中发挥着重要作用。氧化钒催化剂，也是吸附化合物的光化学活化方法，由于其金属氧化物的分散性比浸渍方法更高，因此具有更高的光催化活性。