Highly efficient and stable catalysts-covalent organic framework-supported palladium particles for 4-nitrophenol
Xin Deng1, Lihua Zhu2, Huan Zhang1
1Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, College of Chemistry and Chemical Engineering, Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, 341000, Jiang Xi, China.
Abstract:
A covalent organic framework (COF) was used as the support of the catalyst in this work in order to obtain an environmentally friendly catalyst with high catalytic performance, selectivity and stability for 4-nitrophenol hydrogenation. Pd tiny particles are fixed in the cavity of COF to obtain Pd/COF catalysts, which has a quite narrow particle size distribution (5.09 ± 1.30 nm). As-prepared Pd/COF catalysts (Pd loading-2.11 wt%) shows excellent catalytic performance (conversion - 99.3%, selectivity >99.0% and turnover frequency (TOF)-989.4 h-1) for 4-nitrophenol hydrogenation under relatively mild reaction conditions of reaction temperature-40 °C and reaction pressure-3.0 MPa H2, and Pd/COF catalysts have high stability. Pd/COF catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscope (TEM), high resolution TEM (HRTEM), Brunauer-Emmett-Teller (BET), scanning TEM energy-dispersive X-ray spectroscopy (STEM-EDS) elemental analysis techniques to prove that the Pd nanoparticles are highly dispersed on the COF. Pd/COF catalysts have good stability and reusability hence with certain industrial application value.
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