螯合剂辅助合成高活性CuO/CeO2催化剂及其催化氧化异丁烷制叔丁醇OA

Three CuO/CeO2 catalysts modified with different chelating agents(β-cyclodextrin,D-glucose,and trimesic acid),denoted as βCuO/CeO2,pCuO/CeO2,and jCuO/CeO2,were synthesized by the sol-gel method.Isobutane was selectively oxidized to tert-butanol using O2 as the oxygen source.The catalysts were characterized by XRD,high-resolution TEM,N2 adsorption-desorption,H2-TPR,O2-TPD,XPS,AES and electron paramagnetic resonance.The catalytic activities of different catalysts were evaluated,and the reaction mechanism was analyzed.The experimental results show that the βCuO/CeO2 catalyst exhibits the highest catalytic activity.Under the conditions of a catalyst amount of 0.06 g,an isobutane/O2 molar ratio of 10,a reaction temperature of 130℃,and a reaction time of 60 min,the O2 conversion reaches 92.2%,and the selectivity of tert-butanol is 82.4%.The characterization results indicate that the high catalytic activity of CuO/CeO2 is closely related to the spatial configuration of the chelating agent during the preparation process.The three-dimensional cavity structure of β-cyclodextrin is favorable for improving the dispersion of CuO,and increasing the atomic ratios of Cu+/Cu2+and Ce3+/Ce4+,which promotes the redox cycle between Cu-Ce species and facilitates the generation of surface defect sites and active oxygen species.In addition,an appropriate chelating agent enhances the interaction between CuO and CeO2,promotes the formation of Cu-O-Ce interface,and consequently improves the catalytic activity and stability of the catalyst.