乙酸在SmO_x/Rh(100)模型表面上的吸附和分解  

Adsorption and Decomposition of Acetic Acid on SmO_x/Rh(100) Model Surface

作　　者：马运生[1] 姜志全[2] 周维平[2] 谭大力[2] 翟润生[2] 包信和[2] 庄叔贤[1] 

机构地区：[1]中国科学技术大学化学物理系,安徽合肥230026 [2]中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023

出　　处：《催化学报》2002年第3期219-222,共4页

基　　金：国家自然科学基金 (2 9873 0 42 );催化基础国家重点实验室基金资助项目

摘　　要：用高分辨电子能量损失谱 (HREELS)和热脱附谱 (TDS)研究了乙酸在SmOx/Rh(10 0 )模型表面上的吸附与分解 .结果表明 :低温下吸附乙酸时 ,SmOx 的加入明显促进了乙酸分子中O H键的断裂 ,从而有利于乙酸根的形成 ;升高表面温度 ,SmOx 的存在促进了乙酸根中C C键的断裂 ,有利于乙酸根的进一步分解 .12 0K时 ,乙酸在SmOx/Rh(10 0 )上主要以乙酸根的形式存在 .2 2 5K时 ,乙酸根即可发生以生成CO为主的脱羧反应 .在 4 17和 4 77K观察到受表面脱羧反应控制的CO2 和H2 的脱附峰 .The adsorption and decomposition of acetic acid on SmOx/Rh ( 100) model surface were investigated with high resolution electron energy loss spectroscopy (HREELS) and thermal desorption spectroscopy (TDS). The presence of SmOx weakened O-H bond in acetic acid molecules and therefore facilitated the formation of adsorbed acetate at 120 K. Increasing the temperature, the addition of SmOx promoted further the decomposition of adsorbed acetate by weakening C-C bond. Upon adsorption on SmOx/Rh(100) surface at 120 K, most acetic acid molecules produced adsorbed acetate species via O-H bond cleavage. When the sample was heated to about 225 K, the decarboxylation of acetate occurs and CO is the main product. The CO and H, peaks were also observed at 417 K and 477 K, which could be attributed to reaction-limited products. The reaction mechanism was also discussed in this paper.

关 键 词：分解 乙酸 氧化杉 铑 热脱附谱 高分辨电子能量损失谱 表面吸附 负载型催化剂 一氧化碳 加氢反应 

分 类 号：O643.3[理学—物理化学]