Silicoaluminophosphate（SAPO） molecular sieves doped with cobalt（Co-SAPO-5） were synthesized hydrothermally with different concentrations of *** sample was characterized by X-ray diffraction,N2 adsorption-desorptio...
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Silicoaluminophosphate（SAPO） molecular sieves doped with cobalt（Co-SAPO-5） were synthesized hydrothermally with different concentrations of *** sample was characterized by X-ray diffraction,N2 adsorption-desorption,scanning electron microscopy,ultraviolet-visible spectroscopy,temperature-programmed desorption of NH3（NH3-TPD）,and infrared spectrascopy of adsorbed pyridine（Py-IR）.The results showed that Co was highly dispersed in the Co-SAPO-5 *** addition,a part of the Co content had been incorporated into the SAPO-5 framework,while the remainder existed on the surface as extra-framework *** surface areas of the Co-SAOP-5 samples were similar to the SAPO-5 ***,the pore volumes of the Co-SAOP-5 samples were lower than that of the SAOP-5 *** the concentration of Co increased,the pore volume gradually decreased because extra-framework cobalt oxide was present on the catalyst ***3-TPD and Py-IR results revealed that the amount of Br（？）nsted acid and the total amount of acid for the Co-SAPO-5 samples were higher than that for the SAPO-5 *** values were also higher for samples with higher Co *** catalytic activity of the Co-SAPO-5 samples was evaluated for the oxidation of cyclohexane with molecular *** Co was added to the SAPO-5 catalyst,the catalytic activity of the Co-SAPO-5 catalysts *** addition,the conversion of cyclohexane increased as the Co content in the Co-SAPO-5 catalysts ***,with a high conversion of cyclohexane（6.30%）,the total selectivity of cyclohexanone（K） and cyclohexanol（A） decreased *** K/A ratio ranged from 1.15 to *** effects of reaction conditions（i.e.,reaction temperature,reaction time,initial oxygen pressure,and the catalyst amount） on the performance of the Co-SAPO-5 catalysts have also been ***,the stability of the Co-SAPO-5 catalyst was explored and found to be good for the selective oxidation of cyclohexane by molecular oxygen.
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