高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (1): 115-125.doi: 10.7503/cjcu20160411

• 物理化学 • 上一篇    下一篇

铈基与钴基Co3O4-CeO2氧载体上甲烷化学链转化特性: 产物选择性控制

曾良鹏1, 黄樊2, 祝星1, 郑敏1, 李孔斋1()   

  1. 1. 昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室, 昆明 650093
    2. 昆明理工大学化学工程学院, 昆明 650500
  • 收稿日期:2016-06-07 出版日期:2017-01-10 发布日期:2016-12-15
  • 作者简介:联系人简介: 李孔斋, 男, 博士, 教授, 主要从事能源催化方面的研究. E-mail: kongzhai.li@aliyun.com
  • 基金资助:
    国家自然科学基金(批准号: 51374004, 51204083)、 云南省中青年学术技术带头人后备人才计划(批准号: 2014HB006)、 云南省应用基础研究计划(批准号: 2014FB123)和昆明理工大学校人才培养项目(批准号: KKZ3201352038)资助.

Chemical Looping Conversion of Methane over CeO2-based and Co3O4-based Co3O4-CeO2 Oxygen Carriers:Controlling of Product Selectivity

ZENG Liangpeng1, HUANG Fan2, ZHU Xing1, ZHENG Min1, LI Kongzhai1,*()   

  1. 1. State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology, Kunming 650093, China
    2. Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China
  • Received:2016-06-07 Online:2017-01-10 Published:2016-12-15
  • Contact: LI Kongzhai E-mail:kongzhai.li@aliyun.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.51374004, 51204083), the Candidate Talents Training Fund of Yunnan Province, China(No.2014HB006), the Applied Basic Research Program of Yunnan Province, China(No.2014FB123) and the Talents Training Program of Kunming University of Science and Technology, China(No.KKZ3201352038).

摘要:

采用水热法制备了Co3O4/CeO2(x)[x为钴铈原子摩尔比n(Co):n(Ce)=6:49:1]和Ce1-yCoyO2-δ(y=0.10.4)2个系列复合氧化物, 并表征了材料的物理化学性质, 考察了这些氧化物作为氧载体参与甲烷化学链转化(化学链燃烧和化学链部分氧化)的反应性能. 结果表明, 2类复合氧化物的甲烷反应活性均明显优于单一氧化物CeO2或Co3O4, 但2类氧载体上的甲烷反应产物的选择性具有明显差异. Ce1-yCoyO2-δ氧载体形成了Ce-Co-O固溶体, 储氧能力明显增强, 体相晶格氧迁移速率与甲烷活化速率匹配较好, 甲烷反应产物以CO和H2的合成气为主, 有利于甲烷的化学链部分氧化. Co3O4/CeO2(x)氧载体中CeO2与Co3O4之间的相互作用改善了材料的储氧能力和氧化活性, 其与甲烷反应时主要生成CO2, 有利于甲烷化学链燃烧. 连续性化学链循环实验表明, 2类氧载体均具有较好的再生性能和循环稳定性.

关键词: 甲烷, Co3O4/CeO2(x)氧载体, Ce1-yCoyO2-δ氧载体, 化学链部分氧化, 化学链燃烧

Abstract:

Two series of Co3O4/CeO2(x)[x is the molar ratio of cobalt and cerium atoms, n(Co)/n(Ce)=5:5―9:1] and Ce1-yCoyO2-δ(y=0.1—0.4) composite oxides were prepared by the hydrothermal method. The physicochemical properties of these oxides were characterized by means of X-ray powder diffraction(XRD), BET(Brunauer-Emmett-Teller) surface area, temperature-programmed reduction(TPR) and Raman spectrum technologies. The prepared materials were used as an oxygen carrier for chemical looping conversion of methane in a fixed-bed reactor. The results showed that both the Co3O4/CeO2(x) and Ce1-yCoyO2-δ oxygen carriers exhibited higher reactivity for methane conversion than single cerium oxide and cobalt oxide. However, the selectivity of CO2 and CO in the CH4 reaction over the two types of samples are significantly different. Owing to a larger surface area and the formation of Ce-Co-O solid solution, the oxygen storage capacity of Ce1-yCoyO2-δ oxygen carrier was improved significantly. Moreover, the reaction of Ce1-yCoyO2-δ with methane mainly generated CO and H2 due to good matching between the lattice oxygen mobility and the methane activation rate. On the other hand, the strong interaction between CeO2 and Co3O4 also strongly enhanced the oxygen storage capacity and activity of Co3O4/CeO2(x) oxygen carriers. But they mainly concerted the methane to CO2 and H2O owning to the relatively high concentration of active oxygen. In conclusion, the Co3O4/CeO2(x) composite oxides can be used as oxygen carriers for chemical looping combustion of methane, while the Ce1-yCoyO2-δ oxidesare more suitable for the chemical looping partial oxidation of methane to produce syngas. The sequential cyclic reaction experiments indicated that both the two types of oxygen carriers showed high stability during the successive redox testing.

Key words: Methane, Co3O4/CeO2(x) oxygen carriers, Ce1-yCoyO2-δ oxygen carriers, Chemical looping partial oxidation, Chemical looping combustion

中图分类号: