A sequence of alkali metal cation-exchanged Co metal-organic frameworks(Co-MOFs),therein after denoted as M@Co-MOF,M=Na+,K+,Rb\and Cs+,was prepared and used as the precursors to obtain the corresponding alkali doped c...A sequence of alkali metal cation-exchanged Co metal-organic frameworks(Co-MOFs),therein after denoted as M@Co-MOF,M=Na+,K+,Rb\and Cs+,was prepared and used as the precursors to obtain the corresponding alkali doped cobalt oxide(defined as M/C03O4,M=Na+,K\Rb\and Cs+)through calcination under air atmosphere.The cobalt oxide modified by unifbnn alkali metals exhibited a significant promotion of catalytic activity for CO oxidation.The activity of M/Co3O4 decreased in the order of Cs+>Na+>K+>Rb+.Experimental and theoretical results revealed that the anionic skeleton of Co-MOF could tacilely adsorb alkali metal cations and play a cnicial role in the formation of higlily unilonn alkali doped cobalt oxide.The further characterizations,such as temperature-programmed reduction of H2(H2-TPR),oxygen temperature-programmed desorption(O2-TPD),X-ray photoelectron spectroscopy(XPS),and in situ diffuse reflectance infrared Fourier transiorm(DRIFT)spectra demonstrated that the enlianced catalytic activity is originated from the interfacial electron transfer as well as weakened the Co-O bond strength,which promoted oxygen desorption from CO3O4 and fomiation of cobalt species with the lower valence state.The Cs/Co3O4 catalyst was maintained for 60 h without deactivation and still showed a high activity in the presence of water.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.21661020,21961021).
文摘A sequence of alkali metal cation-exchanged Co metal-organic frameworks(Co-MOFs),therein after denoted as M@Co-MOF,M=Na+,K+,Rb\and Cs+,was prepared and used as the precursors to obtain the corresponding alkali doped cobalt oxide(defined as M/C03O4,M=Na+,K\Rb\and Cs+)through calcination under air atmosphere.The cobalt oxide modified by unifbnn alkali metals exhibited a significant promotion of catalytic activity for CO oxidation.The activity of M/Co3O4 decreased in the order of Cs+>Na+>K+>Rb+.Experimental and theoretical results revealed that the anionic skeleton of Co-MOF could tacilely adsorb alkali metal cations and play a cnicial role in the formation of higlily unilonn alkali doped cobalt oxide.The further characterizations,such as temperature-programmed reduction of H2(H2-TPR),oxygen temperature-programmed desorption(O2-TPD),X-ray photoelectron spectroscopy(XPS),and in situ diffuse reflectance infrared Fourier transiorm(DRIFT)spectra demonstrated that the enlianced catalytic activity is originated from the interfacial electron transfer as well as weakened the Co-O bond strength,which promoted oxygen desorption from CO3O4 and fomiation of cobalt species with the lower valence state.The Cs/Co3O4 catalyst was maintained for 60 h without deactivation and still showed a high activity in the presence of water.
