ESR研究CO,CH_3OH,HCHO和CO+H_2等体系在MgO新鲜表面上的反应  

ESR STUDIES OF THE REACTIONS OF CO,CH_3OH,HCHO, AND CO + H_2 ON FRESH SURFACE OF MgO

作　　者：胡强[1] 陈士明[1] 郭时清 

机构地区：[1]复旦大学分析测试中心

出　　处：《Chinese Journal of Catalysis》1989年第4期335-339,共5页催化学报（英文）

摘　　要：氧化镁经机械粉碎后,形成具有高活性中心的新鲜表面。将一氧化碳、甲醛、甲醇分别吸附在氧化镁新鲜表面上,用ESR分别检测到CO_2^-,(CH_2O^-)(ads),和(CH_2^-)(ads)等负离子自由基的信号。而CO+H_2在氧化镁新鲜表面上反应形成了顺磁性的中间态,当温度升至573K时,该吸附态转变成两种新的吸附态:一种是甲醇形式的吸附态(OCH_2^-)(ads),该吸附态在温度大于643K时发生脱附;另一种是甲醛形式的吸附态(CH_2—O^-),该吸附态在温度大于823K时才脱附。最后,提出了CO+H_2在氧化镁新鲜表面上反应的可能机理。High active fresh surfaces of MgO were formed by the process of MgO fracture. When CO, CH3OH, HCHO were adsorbed on the fresh MgO surfaces, ESR signals of CO2-, ∈OCH2-)(ads) and ∈CH2O-)(ads) radicals were detected respectively. The reaction of CO+H2 on the fresh MgO surfaces formed a paramagnetic intermediate, and when the temperature was raised to 573K the intermediate was turned to two new paramagnetic adspecies, one was the me-thanol adsorbed state ∈OCH2-)(ads), which desorbed at above 643K; the other was the formaldehyde adsorbed state ∈CH2O-)(ads), which desorbed at above 823K. A reaction mechanism of CO + H2 on the fresh surfaces of MgO was proposed.

关 键 词：氧化镁 新鲜表面 CO 甲醇 吸附 

分 类 号：TQ426.81[化学工程]