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摘要
Efficient and low-cost oxygen reduction reaction (ORR) electrocatalyst plays a key role for fuel cells. In this paper, ORR active metal organic framework (MOF: Cu-bipy-BTC, bipy = 2,2′-bipyridine, BTC = 1,3,5-Tricarboxylate) was prepared using hydrothermal method, and then carbon-based material MOF-800 was obtained from pyrolyzing Cu-bipy-BTC at 800 ?C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption isotherm and X-ray photolectron spectroscopy (XPS) were used to characterize the morphologies and structures of the catalysts. Linear sweep voltammetry (LSV) and current-Time curve (i-T) were adopted to evaluate the electrocatalytic properties of the catalysts. The results showed that the MOF-800 originated a certain amount of micropores (0.5 ~ 1.3 nm) compared with the MOF precursor. The MOF-800 had excellent electrical conductivity with a charge transfer resistance of 10.6 Ω, reduced by 97.2% compared to Cu-bipy-BTC. It also exhibited excellent ORR electrocatalytic performance with the onset potential of ca. -0.04 V (vs. Ag/AgCl) and the electron transfer number close to 4. As a Cu, N-incorporated carbon-based catalyst, MOF-800 had good electrical conductivity, and the large amounts of pyridinic, pyrrolic and graphitic nitrogen provided abundant active sites (C-N, Cu-Nx), which resulted in the improved ORR electrocatalytic activity. This study provided technical and theoretical validations for the improvements in electrical conductivity and ORR catalytic performance of Cu-bipy-BTC by pyrolyzing. ? 2019 Chinese Chemical Society.
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