物理化学学报 >> 2017, Vol. 33 >> Issue (9): 1855-1864.doi: 10.3866/PKU.WHXB201704282

论文 上一篇    下一篇

OL负载Cu催化剂及其催化氧化CO及乙酸乙酯性能

傅之丹,臧佳欣,叶青*(),程水源,康天放   

  • 收稿日期:2017-03-17 发布日期:2017-07-05
  • 通讯作者: 叶青 E-mail:yeqing@bjut.edu.cn
  • 基金资助:
    国家自然科学基金(21277008);国家自然科学基金(20777005);北京市自然科学基金(8082008);和北京市教委教师队伍建设(IDHT20140504)

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

Zhi-Dan FU,Jia-Xin ZANG,Qing YE*(),Shui-Yuan CHENG,Tian-Fang KANG   

  • Received:2017-03-17 Published:2017-07-05
  • Contact: Qing YE E-mail:yeqing@bjut.edu.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21277008);The project was supported by the National Natural Science Foundation of China(20777005);Natural Science Foundation of Beijing, China(8082008);Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(IDHT20140504)

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Cux/OL催化剂。利用X射线衍射(XRD)、电子扫描电镜(SEM)、N2吸附/脱附、H2-程序升温还原(H2-TPR)、TG(热重)、X射线光电子能谱(XPS)、O2-程序升温脱附(O2-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Cux/OL的还原性、氧移动性及催化剂表面Cu2+/CuO、(Mn2++Mn3+)/Mn4+和Oads/Olatt的比例。Cux/OL的催化性能与以上因素密切相关。在Cux/OL样品中,Cu5/OL催化剂具有最佳的催化活性(CO催化氧化,T50=70 ℃和T90=100 ℃;乙酸乙酯催化氧化T50=160 ℃,T90=200 ℃)。同时,Cu5/OL催化剂具有最佳的还原性能、氧移动性能和最多的Cu2+、(Mn2++Mn3+)和表面吸附氧浓度。Cux/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。

关键词: 层状锰氧化物, Cux/OL, 一氧化碳, 乙酸乙酯, 催化氧化

Abstract:

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 loadings. 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, Cux/OL samples had different reducibility, oxygen mobility, and atomic ratio of Cu2+/CuO, (Mn2++Mn3+)/Mn4+, and Oads/Olatt after the addition of Cu to OL. Among the Cux/OL samples, the Cu5/OL sample showed the best activity for the catalytic oxidation of CO and ethyl acetate (T50=70 and T90=100℃ for CO oxidation; T50=160℃ and T90=200℃ for ethyl acetate oxidation). Cu5/OL showed the best reducibility, most isolated Cu2+ species, highest surface (Mn2++Mn3+)/Mn4+ atomic ratio, highest chemisorbed oxygen species, and lowest O2 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.

Key words: Octahedral layered birnessite, Cux/OL, Carbon monoxide, Ethyl acetate, Catalytic oxidation

MSC2000: 

  • O643