Co_3O_4表面物种对甲醛氧化催化性能的影响  

Influence of the Surface Species over Co_3O_4 on the Formaldehyde Catalytic Oxidation Performance

作　　者：张叶[1] 周佳佳[1] 吴贵升[1] 毛东森[1] 卢冠忠[1,2] 

机构地区：[1]上海应用技术学院化学与环境工程学院催化研究所,上海201418 [2]华东理工大学化学系工业催化研究所,上海200237

出　　处：《高等学校化学学报》2014年第12期2598-2604,共7页Chemical Journal of Chinese Universities

基　　金：上海市教育委员会重点学科建设项目(批准号:J51503)资助~~

摘　　要：采用沉淀法制备了Co3O4催化剂,并将催化剂在流动的N2或O2气氛中于不同温度下进行预处理.通过X射线衍射(XRD)、热重-差示扫描量热分析(TG-DSC)、程序升温脱附(O2/CO2-TPD,HCHO-TPSR)和原位漫反射傅里叶变换红外光谱(in situ DRIFTS)等手段对催化剂表面物种进行了表征.结果表明,Co3O4-N2-200催化剂表面存在Co3+不饱和配位中心和丰富的弱配位氧负离子,容易形成双配位的甲酸盐,并转化成单配位的甲酸盐,进一步分解为产物.The Co3 O4 catalysts were prepared via precipitation methods, and then were pretreated in N2 or O2 at different temperatures. Based on the study of formaldehyde catalytic oxidation, the catalytic performances were investigated with the detailed surface characterization via temperature programmed desorption （ O2/CO2-TPD, HCHO-TPSR） , thermogravimetric-differential scanning calorimetry（ TG-DSC） and in situ diffuse reflec-tance infrared fourier transform spectroscopy （ in situ DRIFTS ） . The results presented that Co3 O4-N2-200 showed the optimal catalytic performance, because there were rich unsaturated coordination centers of Co3＋and negative oxygen ions with weak bond strength on the surface of Co3 O4-N2-200, which was ready to adsorb formaldehyde to form bidentate formate, and then decompose to products via monodentate formate. With increasing pretreatment temperature, the amount of negative oxygen ions decreased, accordingly the catalytic activity for formaldehyde catalytic oxidation decreased due to slow decomposition rate of desorbed bidentate formate.

关 键 词：甲醛催化氧化 四氧化三钴 甲酸盐 程序升温脱附 原位漫反射红外光谱 表面氧 

分 类 号：O646[理学—物理化学]