高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (6): 20230095.doi: 10.7503/cjcu20230095

• 物理化学 • 上一篇    

基于水滑石衍生钌催化剂光驱动合成氨的研究

卞宣昂1,2, 周超1, 赵运宣1, 张铁锐1,2()   

  1. 1.中国科学院理化技术研究所, 光化学转换与功能材料重点实验室, 北京 100190
    2.中国科学院大学材料科学与光电技术中心, 北京 100049
  • 收稿日期:2023-03-08 出版日期:2023-06-10 发布日期:2023-03-21
  • 通讯作者: 张铁锐 E-mail:tierui@mail.ipc.ac.cn
  • 基金资助:
    国家重点基础研究发展计划项目(2021YFA1500803);国家自然科学基金(51825205);中国科学院DNL合作基金(DNL202016);中国科学院稳定支持基础研究领域青年团队计划项目(YSBR-004);中国博士后科学基金(BX2021323)

Light-driven Ammonia Synthesis over Layered-double- hydroxide-derived Ru Catalyst

BIAN Xuanang1,2, ZHOU Chao1, ZHAO Yunxuan1, ZHANG Tierui1,2()   

  1. 1.Key Laboratory of Photochemical Conversion and Optoelectronic Materials,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China
    2.Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2023-03-08 Online:2023-06-10 Published:2023-03-21
  • Contact: ZHANG Tierui E-mail:tierui@mail.ipc.ac.cn
  • Supported by:
    the National Key Projects for Fundamental Research and Development of China(2021YFA1500803);the National Natural Science Foundation of China(51825205);the DNL Cooperation Fund, Chinese Academy of Sciences(DNL202016);the CAS Project for Young Scientists in Basic Research(YSBR-004);the China Postdoctoral Science Foundation(BX2021323)

摘要:

通过在还原性气氛中煅烧钌基水滑石前驱体, 制备了高度分散于金属氧化物纳米片上的钌纳米颗粒(MgAlRu-500R). 利用X射线衍射(XRD)、 高分辨透射电子显微镜(HRTEM)、 X射线光电子能谱(XPS)和紫外- 可见-近红外漫反射光谱(UV-Vis-NIR DRS)对MgAlRu-500R的晶体结构、 形貌、 元素组成和光学特性进行分析表征. 基于流动相反应体系研究了MgAlRu-500R催化剂在常压条件下的光热催化合成氨性能. 结果表明, MgAlRu-500R可以仅依靠光照升温至300 ℃以上, 并驱动光热催化合成氨反应. 在380 ℃下, MgAlRu-500R光热催化合成氨速率高达3.0 mmol·g‒1·h‒1, 显著高于相同温度下的热催化合成氨速率(1.5 mmol·g‒1·h‒1). 动力学分析(包括表观活化能和动力学反应级数的测定)结果表明, 优异的光热催化合成氨活性是因为光激发加速了N2解离, 进而降低了反应活化能.

关键词: 合成氨, 光热催化, 层状双金属氢氧化物, 钌催化剂

Abstract:

The metal oxide nanosheet-supported Ru nanoparticles(MgAlRu-500R) were prepared via calcining the Ru-based layered double hydroxide(MgAlRu-LDH) in a reductive atmosphere. X-Ray diffraction(XRD), high resolution transmission electron microscopy(HRTEM), X-ray photoelectron spectroscopy(XPS) and ultraviolet- visible-near-infrared diffuse reflectance spectroscopy(UV-Vis-NIR DRS) were employed to characterize the crystal structure, morphology, component and optical properties of MgAlRu-500R. The photothermal catalytic performance of MgAlRu-500R for ammonia synthesis was investigated in a flow-type reaction system at normal pressure. The results demonstrated that MgAlRu-500R can be heated up to more than 300 ℃ by light illumination as sole energy source and drived the photothermal catalytic ammonia synthesis reaction. Notably, MgAlRu-500R delivered a high ammonia production of 3.0 mmol·g‒1·h‒1 at 380 oC, markedly exceeding that of thermocatalytic process at the same temperature(1.5 mmol·g‒1·h‒1). Furthermore, in-depth kinetic analysis(determinations of apparent activation energy and kinetic reaction order) attributes the outstanding catalytic activity to the reduced activation energy caused by photoexcitation-accelerated N2 dissociation. This work provides a highly active catalyst with simple preparation method for photothermal ammonia synthesis, which will promote the development of green ammonia synthesis technology.

Key words: Ammonia synthesis, Photothermal catalysis, Layered double hydroxide, Ruthenium catalyst

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