Static and Dynamic Effects of Ferroelectric Piezoelectrics upon Adsorptive Catalytic Properties of Combined Thin Metal and Semiconducting Oxide Films.

铁电压电体对金属和半导体氧化物组合膜吸附催化性能的静态和动态影响。

基本信息

批准号：
61470003
负责人：
INOUE Yasunobu
金额：
$ 3.71万
依托单位：
Technological University of Nagaoka
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

A poled ferroelectric piezoelectrics exposes the positive and negative polar suraces and permits the generation of surface acoustic wave(SAW). In the present work, a poled single crystal of lithium niobate(LinbO_3) was employed as support on which catalytically active phases such as semiconducting oxides(TiO_2,SnO) or metal(Pd) were deposited as thin layers. The static effects of polarization-direction of the support as well as the dynamic effects due to SAW(20 MHz) upon the adsorptive and catalytic properties of the combined catalytically active phases were studied. The changes in surface conductivity due to the chemisorption of various gases such as H_2,CO,CO_2 and C_2H_4 on TiO_2/LiNbO_3 and SnO/LiNbO_3 were markedly greater than for the positive polar support than for the negative polar one, and the differences between the polar supports became larger with increasing ionization potential of the adsorbed gases. These polar direction-dependences were accounted for in terms of band bending caused in the semiconducting oxides by contact with LinbO_3 surface. For the Pddeposited SAW catalysts, the intensity of SAW was found to be sensitive to the adsorption of small amounts of O_2 and H_2. The SAW effects were examined for different kinds of catalytic reactions such as oxidation (CO+O_2, H_2+o_2), decomposition (CH_3OH, CH_3 OH+O_2) and hydrogenation (C_2H_4+H_2), and it was observed that the dynamic SAW effects were prominent for the reactions involving polar molecules.

螺旋的铁电压电揭示了正极和负极的表面，并允许产生表面声波（SAW）。在目前的工作中，使用二甲锂锂（Linbo_3）的单晶作为支撑，将催化活性相（例如半导体氧化物（TIO_2，SNO）或金属（PD）作为薄层沉积。研究了支持（20 MHz）对组合催化活性相的吸附和催化特性引起的支撑的极化方向以及动态效应的静态效应。 TIO_2/LINBO_3和SNO/LINBO_3上的H_2，CO，CO_2和C_2H_4等各种气体化学吸附引起的表面电导率的变化明显大于对负极支撑的积极支撑，而对负极支撑物的差异高，并且在极性支撑之间的差异随着吸收型气体的电离潜力而更大。这些极性方向依赖性是根据与Linbo_3表面接触在半导体氧化物中引起的带弯曲的。对于PDDEPOSSED SAW催化剂，发现SAW的强度对少量O_2和H_2的吸附敏感。检查了各种催化反应的锯效应，例如氧化（CO+O_2，H_2+O_2），分解（CH_3OH，CH_3OH，CH_3 OH+O_2）和氢化（C_2H_4+H_2），并且观察到涉及极性分子的反应的动力学作用是显着的。