无机盐工业

无机盐工业 ›› 2021, Vol. 54 ›› Issue (4): 95-100.doi: 10.11962/1006-4990.2020-0265

• 催化材料 • 上一篇    下一篇

焙烧温度对MnZnOx物化性质及催化性能的影响

肖亦寒1,2,3,曹建新1,2,3(),刘飞1,2,3(),易芸1,2,3   

  1. 1.贵州大学化学与化工学院,贵州贵阳 550025
    2.贵州省绿色化工与清洁能源技术重点实验室
    3.贵州省工业废弃物高效利用工程研究中心
  • 收稿日期:2020-10-15 出版日期:2021-04-01 发布日期:2021-04-23
  • 通讯作者: 刘飞
  • 作者简介:肖亦寒(1995— ),男,硕士研究生,研究方向为碳基小分子转化利用;E-mail: 970093466@qq.com
  • 基金资助:
    国家自然科学基金项目(21666007);贵州省百层次创新型人才专项(黔科合平台人才)([2016]5655);贵州省科技创新人才团队(黔科合平台人才)([2018]5607);贵州省科技计划项目(黔科合平台人才)([2017]5788号);贵州省科技计划项目(黔科合平台人才)([2018]5781号);贵州省科学技术基金项目(20177260);贵州省科技支撑计划项目(20182192)

Effect of calcination temperature on physicochemical properties and catalytic performance of MnZnOx

Yihan Xiao1,2,3,Jianxin Cao1,2,3(),Fei Liu1,2,3(),Yun Yi1,2,3   

  1. 1. School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China
    2. Guizhou Key Laboratory for Green Chemical and Clean Energy Technology
    3. Guizhou Engineering Research Center of Efficient Utilization for Industrial Waste
  • Received:2020-10-15 Online:2021-04-01 Published:2021-04-23
  • Contact: Fei Liu

摘要:

采用湿化学共沉淀法制备了MnZnOx固溶结构催化剂,考察了焙烧温度对催化剂物化性质和催化性能的影响。采用X射线衍射(XRD)、X射线光电子能谱(XPS)、N2吸附-脱附、CO2-TPD(程序升温脱附)及H2-TPR(程序升温还原)等手段对不同焙烧温度下催化剂物化性质进行了分析表征。结果表明,焙烧温度对MnZnOx晶相组成、孔结构性质、二氧化碳吸附特性及表面氧空位浓度等物化性质影响较大。500 ℃焙烧条件下制得的MnZnOx催化剂形成了具有丰富的表面氧空位、较大的二氧化碳吸附量和介孔孔容且溶质组分分散均匀的固溶结构。在反应压力为3.0 MPa、反应空速(GHSV)为14 400 mL/(g·h)、V(氢气)∶V(二氧化碳)∶V(氮气)=72∶24∶4条件下,MnZnOx催化剂于380 ℃表现出优异的催化性能,甲醇选择性为86.1%、二氧化碳转化率为16.0%、甲醇时空产率(STY)达0.68 gMeOH /(h·gcat)。

关键词: MnZnOx, 固溶结构, 焙烧温度, 氧空位, CO2加氢

Abstract:

The rapid development of global industry had aggravated a large amount of greenhouse gas (CO2)emissions.It is of great significance to convert CO2 to methanol by reduction and activation of high energy hydrogen molecules.Wet chemical co-precipitation strategy was employed to fabricate the MnZnOx solid solution catalyst which realized the hydrogenation of CO2 to methanol and the influence of calcination temperature on physicochemical properties and catalytic performance of the catalysts were fully investigated in this paper.X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),N2 adsorptiondesorption,CO2-TPD and H2-TPR techniques were used to characterize the physicochemical properties of the catalysts calcined at various temperature.The results showed that the calcination temperature had significant impact on the crystalline phase compositions,pore structure properties,CO2 adsorption characteristics and surface oxygen vacancy concentrations of MnZnOx.Although the homogeneous solid solution structure could be formed at lower temperature,the crystallinity of the main crystal phase ZnO was inferior.Too high calcination temperature made the solute component MnxOy crystallize in the form of Mn3O4 and the mixed crystal phase of Mn3O4 and ZnO was formed in the structure,resulting in the decrease of specific surface area and mesoporous pore volume.MnZnOx catalyst calcinated at 500 ℃ had a solid solution structure with abundant surface oxygen vacancy,large CO2 adsorption and mesoporous pore volume and uniform dispersion of solute components.Under the conditions as follows:reaction pressure of 3.0 MPa,reaction space velocity(GHSV) of 14 400 mL/(g·h) and V(H2)∶V(CO2)∶V(N2)=72∶24∶4,the MnZnOx at 380 ℃ exhibited excellent catalytic performance with methanol selectivity of 86.1%,CO2 conversion of 16.0% and methanol STY of 0.68 g MeOH/(h·gcat).

Key words: MnZnOx, solid solution structure, calcining temperature, oxygen vacancy, CO2 hydrogenation

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