高等学校化学学报 ›› 2016, Vol. 37 ›› Issue (12): 2206-2214.doi: 10.7503/cjcu20160467

• 物理化学 • 上一篇    下一篇

Ca, Sr共掺杂铈氧化物及其在甲烷氧化偶联反应中的应用

杨艳玲, 董玲玉, 夏文生(), 万惠霖()   

  1. 厦门大学化学化工学院, 固体表面物理化学国家重点实验室,醇醚酯化工清洁生产国家工程实验室, 福建省理论计算化学重点实验室, 厦门 361005
  • 收稿日期:2016-07-01 出版日期:2016-12-10 发布日期:2016-11-18
  • 作者简介:联系人简介: 夏文生, 男, 博士, 教授, 主要从事甲烷转化方面的研究. E-mail:wsxia@xmu.edu.cn; 万惠霖, 男, 教授, 中国科学院院士, 主要从事甲烷转化方面的研究. E-mail:hlwan@xmu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21373169)和教育部“长江学者和创新团队发展计划”项目(批准号: IRT1036)资助

Ca, Sr co-Doped Ceria and Its Application in Oxidative Coupling of Methane

YANG Yanling, DONG Lingyu, XIA Wensheng*(), WAN Huilin*()   

  1. State Key Laboratory of Physical Chemistry of Solid State Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, Fujian Province Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
  • Received:2016-07-01 Online:2016-12-10 Published:2016-11-18
  • Contact: XIA Wensheng,WAN Huilin E-mail:wsxia@xmu.edu.cn;hlwan@xmu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21373169) and the Program for Changjiang Scholars and Innovative Research Team in the University, China(No.IRT1036)

摘要:

采用柠檬酸法制备了Ca, Sr共掺杂的CeO2催化剂, 发现共掺杂催化剂较单掺杂或未掺杂催化剂呈现出更好的催化甲烷氧化偶联(OCM)反应性能. 通过表征可知, Ca, Sr共掺杂催化剂的物相为CeO2和SrCO3, Ca高度分散或掺杂于CeO2之中; CeO2的粒径明显变小; 表面呈中等程度碱性; Ce基催化剂上的亲电氧物种数量随着碱土金属的掺杂而增大, 亲电氧物种与晶格氧摩尔比(O22-+O2-/+O2-的大小顺序(CeSrCa>CeSr>CeO2)与C2选择性一致; 且SrCO3相的存在有助于Ce基氧化物催化甲烷氧化偶联反应(OCM)性能的改善.

关键词: 碱土金属, 掺杂, CeO2, 碳酸盐, 甲烷氧化偶联

Abstract:

The Ca and Sr co-doped ceria catalysts were synthesized with a citric acid method and their performances in oxidative coupling of methane(OCM) were significantly enhanced when compared with the single or none doped ceria catalysts. By X-ray diffraction(XRD), CO2 temperature programmed desorption(CO2-TPD), O2 temperature programmed desorption(O2-TPD), X-ray photoelectron spectroscopy(XPS) characterizations, we found that the Ca and Sr co-doped catalysts were consisted of the phases CeO2 and SrCO3, along with Ca highly dispersed or doped in ceria. They exhibited the decreased size of ceria particles and the medium basicity. The number of electrophilic oxygen species and the ratio of electrophilic oxygen species to lattice oxygen species on the catalyst surfaces were changed in the order of CeSrCa>CeSr>CeO2, corresponding to the C2 selectivity in OCM. In addition, the presence of SrCO3 was beneficial to improve on catalytic performances of OCM over Ce-based oxide catalysts.

Key words: Alkali earth, Dope, Ceria, Carbonate, Oxidative coupling of methane