高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (8): 20240212.doi: 10.7503/cjcu20240212

• 物理化学 • 上一篇    

Co物种调控增强Co/SSZ-39催化剂的低温CH4-SCR活性

安素峰1(), 汪鹏1, 王宽岭1, 王学海1, 李宝忠1, 郭新闻2()   

  1. 1.中石化(大连)石油化工研究院有限公司, 大连 116045
    2.大连理工大学化工学院, 大连 116024
  • 收稿日期:2024-04-24 出版日期:2024-08-10 发布日期:2024-06-21
  • 通讯作者: 安素峰 E-mail:ansufeng.fshy@sinopec.com;guoxw@dlut.edu.cn
  • 作者简介:郭新闻, 男, 博士, 教授, 主要从事分子筛酸催化及二氧化碳加氢方面的研究. E-mail: guoxw@dlut.edu.cn
  • 基金资助:
    国家自然科学基金(22202029)

Regulating Co Species over Co/SSZ-39 Catalyst to Enhance the Low-temperature CH4-SCR Activity

AN Sufeng1(), WANG Peng1, WANG Kuanling1, WANG Xuehai1, LI Baozhong1, GUO Xinwen2()   

  1. 1.SINOPEC (Dalian) Research Institute of Petroleum and Petrochemicals,Dalian 116045,China
    2.Chemical Engineering Institute,Dalian University of Technology,Dalian 116024,China
  • Received:2024-04-24 Online:2024-08-10 Published:2024-06-21
  • Contact: AN Sufeng E-mail:ansufeng.fshy@sinopec.com;guoxw@dlut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22202029)

摘要:

以小孔SSZ-39分子筛为载体, 采用浸渍法和离子交换法制备了不同钴(Co)含量的Co/SSZ-39催化剂, 利用X射线衍射仪、 透射电子显微镜、 氮气吸附-脱附和氢气程序升温还原等技术对Co/SSZ-39催化剂进行表征测试, 对比了不同制备方法和不同Co负载量催化剂对CH4选择催化还原NO反应(CH4-SCR)性能的影响. 结果表明, 采用离子交换法经单次离心洗涤, 可以调控分子筛上Co物种的类别, 制备的Co-SSZ-39-S催化剂同时富含离子态Co位点和高分散的活性CoO x 物种, 可以促进CH4低温适度活化, 提高低温条件下CH4选择性还原NO x 的性能. 将制备的催化剂应用于CH4-SCR反应, 在较低反应温度(400 ℃), NO/CH4摩尔比为1∶1时, NO转化率可达68%, CH4转化率可达82%; NO/CH4摩尔比为1∶2时, NO转化率为76%, CH4转化率为81%, 且转化率在50 h内保持稳定. 该催化剂可实现NO x 和CH4的协同去除.

关键词: CH4-SCR, Co/SSZ-39, 甲烷低温活化, 离子交换法

Abstract:

Co/SSZ-39 catalyst with different cobalt(Co) content was prepared by impregnation method and ion exchange method using small-pore SSZ-39 molecular sieve as carrier. The Co/SSZ-39 catalysts were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), nitrogen adsorption-desorption and H2 temperature programming reduction(H2-TPR). The effects of different preparation methods and catalysts with different Co loads on the performance of CH4 selective catalytic reduction of NO(CH4-SCR) were compared. The characterization results showed that the classification of Co species on SSZ-39 can be regulated by ion exchange method along with a single centrifuge washing. The Co/SSZ-39-S catalyst have both ionic Co sites and highly active CoO x species. The highly active CoO x species could promote moderate activation of CH4 at low temperature and improve the selective NO x reduction performance of CH4 at low temperature. When applied to CH4-SCR reaction, the catalyst prepared by this method can achieve 68% NO conversion and 82% CH4 conversion at a lower reaction temperature of 400 ℃(the molar ratio of NO and CH4 is 1∶1). When the molar ratio of NO and CH4 is 1∶2, the catalyst can achieve 76% NO conversion and 81% CH4 conversion, and the conversion rate remains stable within 50 h. The catalyst can realize the collaborative removal of NO x and CH4.

Key words: CH4-SCR, Co/SSZ-39, Low temperature activation of CH4, Ion exchange method

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