Single-Atom Ni Heterogeneous Catalysts Supported UiO-66 Structure: Synthesis and Catalytic Activities

摘要

Herein, the single-atom Ni site heterogeneous catalysts supported by the UiO-66 structure (University of Oslo-66 metal organic framework) were successfully synthesized by a postsynthetic metalation method, where Ni ions are covalently attached to the missing-linker defect sites at zirconium oxide clusters (Zr 6 O 4 (OH) 4 ) in as-prepared UiO-66 structure, [Zr 6 O 4 (OH) 4 (BDC)(DMF) 10 (OH) 10 ] (BDC (benzene-1,4-dicarboxylate), DMF (dimethylformamide)). The structure properties of the catalysts were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), N 2 adsorption-desorption isotherms (BET), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). It was found that single-atom Ni heterogeneous catalysts supported by the UiO-66 structure, UiO-66/Ni1.0 [Zr 6 O 4 (OH) 4 (C 8 H 4 O 4 )(DMF) 10 (OH) 8 Ni 2 (OH) 2 (Cl) 2 ], showed a sphere-like morphology with a high specific surface area as well as good thermal stability. Specifically, the as-prepared UiO-66/Ni1.0 exhibited the excellent catalytic activity and stability for 4-nitrophenol reduction in terms of low activation energy ( ), high turnover frequency (76.19 molecules g -1 min -1 ), and high apparent rate constant ( ). In addition, methylene blue (MB) was also chosen as the organic dye model for catalytic reduction reaction. The and TOF for the reduction of MB using UiO-66/Ni1.0 were 0.787 min ?1 and molecules g ?1 min ?1 , respectively.