催化学报 ›› 2021, Vol. 42 ›› Issue (11): 2038-2048.DOI: 10.1016/S1872-2067(21)63851-2

• 论文 • 上一篇    下一篇

双功能催化剂催化CO2加氢制低碳烯烃反应中In2O3的尺寸效应

卢思宇a,b, 杨海艳a, 周紫璇a,b, 钟良枢a,b,c, 李圣刚a,b,c,*(), 高鹏a,b,#(), 孙予罕a,c,d,$()   

  1. a中国科学院上海高等研究院, 中科院低碳转化科学与工程重点实验室, 上海201210
    b中国科学院大学, 北京100049
    c上海科技大学物质科学与技术学院, 上海201210
    d上海低碳技术创新功能型平台, 上海201620
  • 收稿日期:2021-04-14 修回日期:2021-04-14 接受日期:2021-05-20 出版日期:2021-11-18 发布日期:2021-06-08
  • 通讯作者: 李圣刚,高鹏,孙予罕
  • 基金资助:
    国家自然科学基金(21773286);国家自然科学基金(U1832162);荷兰皇家壳牌集团前瞻科学基金(CW373032);中国科学院洁净能源先导科技专项资助(XDA21090204);中国科学院青年创新促进会(2018330);上海市青年科技启明星计划(19QA1409900)

Effect of In2O3 particle size on CO2 hydrogenation to lower olefins over bifunctional catalysts

Siyu Lua,b, Haiyan Yanga, Zixuan Zhoua,b, Liangshu Zhonga,b,c, Shenggang Lia,b,c,*(), Peng Gaoa,b,#(), Yuhan Suna,c,d,$()   

  1. aCAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
    bUniversity of the Chinese Academy of Sciences, Beijing 100049, China
    cSchool of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
    dShanghai Institute of Clean Technology, Shanghai 201620, China
  • Received:2021-04-14 Revised:2021-04-14 Accepted:2021-05-20 Online:2021-11-18 Published:2021-06-08
  • Contact: Shenggang Li,Peng Gao,Yuhan Sun
  • About author:$E-mail:Tel: +86-551-65591263; Fax: +86-551-65591434; E-mail: sunyh@sari.ac.cn
    #Tel: +86-551-65591263; Fax: +86-551-65591434; E-mail: gaopeng@sari.ac.cn;
    *Tel: +86-551-65591263; Fax: +86-551-65591434; E-mail: lisg@sari.ac.cn;
  • Supported by:
    National Natural Science Foundation of China(21773286);National Natural Science Foundation of China(U1832162);“Frontier Science” Program of Shell Global Solutions International B.V.(CW373032);“Transformational Technologies for Clean Energy and Demonstration”, Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21090204);Youth Innovation Promotion Association(2018330);Shanghai Rising-Star Program, China(19QA1409900)

摘要:

CO2催化加氢转化成高附加值化学品如低碳烯烃(C2=-C4=)等是减少碳排放的有效途径之一. 采用金属氧化物/分子筛双功能催化剂可以实现CO2加氢直接高选择性合成C2+碳氢化合物. 通常认为, 金属氧化物组分可以活化CO2转化为甲醇等含氧中间体, 该中间体在分子筛孔道内进一步转化为各种烃. 氧化铟(In2O3)/SAPO-34双功能催化剂由于具有出色的催化CO2加氢制低碳烯烃反应性能而备受关注, 然而, 仍需进一步提升催化剂的催化性能以推动该反应的工业应用. 目前, 氧化物的结构与双功能催化剂性能之间的关系还不明确, 这不利于其催化性能的改善. 现有关于金属氧化物纳米粒子的尺寸(特别是小于23 nm)效应及其对双功能催化CO2加氢反应的活性和产物分布的影响的报道较少, 对此深入理解将有利于设计更高性能的催化剂.
本文采用沉淀法, 通过控制焙烧温度得到了一系列尺寸为7~28 nm的立方相In2O3, 通过多种表征手段探究了In2O3的尺寸对其结构与表面化学性质的影响. 结果表明, 随着In2O3晶粒尺寸的减小, 其氧空位数目、CO2、H2与NH3吸附量以及Lewis较强酸性位比例均逐渐增加. 在350 ºC, 3 Mpa, 9000 mL·gcat-1·h-1和H2/CO2比为3的反应条件下, 研究了In2O3/SAPO-34双功能催化剂中In2O3粒径对其催化CO2加氢制低碳烯烃反应性能的影响. 结果表明, 随着双功能催化剂中In2O3尺寸的增大, 低碳烯烃(尤其是丙烯)选择性、收率及烯烃与烷烃比例均先升高后降低, 在尺寸为19 nm的In2O3上达到最大值, 分别为76.9%、12.3 mmol goxide- 1 h-1和4.8. 较小尺寸的In2O3虽然具有较大的比表面积和更多的氧空位, 并为CO2和H2的活化提供了更多的活性位, 但小于19 nm的颗粒更容易烧结; In2O3的尺寸还会影响其与SAPO-34的协同效应, 进而影响双功能催化剂的催化活性. 此外, 相对于其它尺寸的In2O3, 19 nm的In2O3更有利于甲醇中间体的生成. 因而19 nm In2O3耦合SAPO-34的双功能催化剂性能最好, 其催化CO2转化率最高, 为14.1%. 综上, 适中尺寸的In2O3能够促进In2O3/SAPO-34上CO2加氢制低碳烯烃反应. 这些结果为通过平衡结构稳定性和催化性能来设计更有效的催化CO2转化的复合催化剂提供了理论指导.

关键词: 二氧化碳加氢, 双功能催化, 尺寸效应, 氧化铟, 低碳烯烃

Abstract:

A reaction-coupling strategy is often employed for CO2 hydrogenation to produce fuels and chemicals using oxide/zeolite bifunctional catalysts. Because the oxide components are responsible for CO2 activation, understanding the structural effects of these oxides is crucial, however, these effects still remain unclear. In this study, we combined In2O3, with varying particle sizes, and SAPO-34 as bifunctional catalysts for CO2 hydrogenation. The CO2 conversion and selectivity of the lower olefins increased as the average In2O3 crystallite size decreased from 29 to 19 nm; this trend mainly due to the increasing number of oxygen vacancies responsible for CO2 and H2 activation. However, In2O3 particles smaller than 19 nm are more prone to sintering than those with other sizes. The results suggest that 19 nm is the optimal size of In2O3 for CO2 hydrogenation to lower olefins and that the oxide particle size is crucial for designing catalysts with high activity, high selectivity, and high stability.

Key words: Carbon dioxide hydrogenation, Bifunctional catalysis, Particle size effect, Indium oxide, Lower olefins