OL负载Cu催化剂及其催化氧化CO及乙酸乙酯性能  

Cu-Doped Octahedral Layered Birnessites Catalysts for the Catalytic Oxidation of CO and Ethyl Acetate

作　　者：傅之丹[1] 臧佳欣 叶青[1] 程水源[1] 康天放[1] 

机构地区：[1]北京工业大学区域大气复合污染防治北京市重点实验室,北京100124

出　　处：《物理化学学报》2017年第9期1855-1864,共10页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21277008;20777005);北京市自然科学基金(8082008);北京市教委教师队伍建设(IDHT20140504)资助项目~~

摘　　要：采用氧化还原法合成了层状锰氧化物(OL),并以OL为载体采用离子交换法制备了不同Cu负载量的Cu_x/OL催化剂。利用X射线衍射(XRD)、电子扫描电镜(SEM)、N_2吸附/脱附、H_2^-程序升温还原(H_2-TPR)、TG(热重)、X射线光电子能谱(XPS)、O_2-程序升温脱附(O_2-TPD)等技术对所制催化剂进行结构和织构表征,并对其催化氧化CO及乙酸乙酯活性进行了评价。结果表明,OL具有典型的层状锰氧化物结构,适量掺杂Cu对OL的结构和织构影响不大,但Cu的掺杂明显影响Cu_x/OL的还原性、氧移动性及催化剂表面Cu^(2+)/CuO、(Mn^(2+)+Mn^(3+))/Mn^(4+)和Oads/Olatt的比例。Cu_x/OL的催化性能与以上因素密切相关。在Cu_x/OL样品中,Cu_5/OL催化剂具有最佳的催化活性(CO催化氧化,T_(50)=70°C和T_(90)=100°C;乙酸乙酯催化氧化T50=160°C,T90=200°C)。同时,Cu_5/OL催化剂具有最佳的还原性能、氧移动性能和最多的Cu^(2+)、(Mn^(2+)+Mn^(3+))和表面吸附氧浓度。Cu_x/OL催化性能与铜锰之间相互作用、还原性和氧移动性能密切相关。Octahedral layered birnessite （denoted as OL） was synthesized by the oxidation-reduction method and a series of Cux/OL catalysts were prepared by the ion exchange method with various Cu ioadings. The materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, N2 adsorption-desorption, hydrogen temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, thermogravimetric （TG） and .oxygen temperature-programmed desorption （O2-TPD） techniques, and their catalytic activities for CO and ethyl acetate oxidation were evaluated. The results show that OL is a typical octahedral layered structure, and the doping of Cu hardly affects the structure of OL. Moreover, CuEOL samples had different reducibility, oxygen mobility, and atomic ratio of Cu2＋/CuO, （Mn2＋ ＋ Mn3＋）/Mn4＋, and Oads/Otatt after the addition of Cu to OL. Among the Cux/OL samples, the Cus/OL sample showed the best activity for the catalytic oxidation of CO and ethyl acetate （T50 = 70 and Tgo = 100℃ for CO oxidation; T50 = 160℃ and T90 = 200℃ for ethyl acetate oxidation）. CuYOL showed the best reducibility, most isolated Cu2＋ species, highest surface （Mn2＋ ＋ Mn3＋）/Mn4＋ atomic ratio, highest chemisorbed oxygen species, and lowest 02 desorption temperature.Hence, factors such as the strong interaction between copper and manganese, good reducibility, and oxygen mobility were responsible for the excellent catalytic activity of Cu5/OL.

关 键 词：层状锰氧化物 Cu_x/OL 一氧化碳 乙酸乙酯 催化氧化 

分 类 号：O643.36[理学—物理化学]