Chem. J. Chinese Universities ›› 2023, Vol. 44 ›› Issue (6): 20230095.doi: 10.7503/cjcu20230095

• Physical Chemistry • Previous Articles    

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)

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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