摘要
本文用原子簇模型（ＣＭ）的从头计算方法，计算了银表面甲醇氧化反应中的静态吸附物种的优化几何构型及吸附性质，计算表明在清洁银表面甲醇，甲醛中存在物理吸附；光表面存在的吸附氧原子时，甲醇可在银表面形成两种分子态吸附，甲醛与表面羟基ＯＨ或氢原子共存在的银表面能够形成化学吸附，且ＣＨ２Ｏ极易与Ｏ反应生成深度氧化中间体η＾－甲二氧基；中间产物甲氧基在无氧的银表面能够形成稳定吸际。
The equilibrium geometries and properties of stationary adsorbates which are produced in the process of oxidation of methanol over silver surface have been calcaulated by the cluster model with ab initio method,Our calaulations show that methanol and formaldehyde have only weak physisorption on clean silver surface; if there is adsorbed oxygen atom O(a)on the surface, methanol can form two stable molecular chemisorption states; formaldehyde can coadsorb with OH(a) or H(a) on silver surface,and adsorbed formaldehyde is very easy to react with O(a) to formη2 - methylendioxy; the intermedidate methoxide can form stable adsorption on clean silver surface and it can easily react with the oxygen on the oxygen - rich silver surface to form formaldehyde. By comparing calculations with experiments,the reaction mechnism of oxidation of methanol over silver surface has been discussed.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1997年第1期13-19,共7页
Acta Chimica Sinica
基金
国家自然科学基金资助项目
