Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (9): 20220388.doi: 10.7503/cjcu20220388

• Article • Previous Articles     Next Articles

Synergistic Catalysis Between Ir Single Atoms and Nanoparticles for N2O Decomposition

YANG Jingyi, LI Qinghe, QIAO Botao()   

  1. Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China
  • Received:2022-06-02 Online:2022-09-10 Published:2022-08-03
  • Contact: QIAO Botao E-mail:bqiao@dicp.ac.cn
  • Supported by:
    the National Natural Science Foundation of China(21961142006)

Abstract:

“Atom trapping” is one of the effective methods to prepare thermally stable single-atom catalysts(SACs) at high temperature. However, the SACs derived from such methods often suffer from poor activity, which inhibits their application. Therefore, developing the application of these SACs is highly desired. In this work, we found that the Ir SACs prepared via atom trapping are inactive towards N2O decomposition, but exhibit a synergistic effect with Ir nanoparticles(NPs) after loading the nanoparticle counterparts. X-ray photoelectron spectroscopy(XPS) and in situ diffuse reflectance infrared spectroscopy of CO adsorption(CO-DRIFTs) characterization combined with kinetic analysis revealed that the metallic Ir NPs are the real active sites in this reaction. Although Ir single atoms(SAs) with high valance state cannot directly activate the N2O, they change the electronic state and adsorption ability of Ir NPs. O2 temperature programmed desorption(O2-TPD) verified that the presence of SAs stimulate the desorption of O2 from Ir NPs thus enhance activity. This work provides new insights into the catalytic role of SAs.

Key words: Single-atom catalyst, Nanoparticle catalyst, Synergistic catalysis, Atom-trapping method

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