Pseudo core-shell LaCoO3@MgO perovskite oxides for high performance methane catalytic oxidation
来源期刊：JOURNAL OF RARE EARTHS2021年第1期
论文作者：Saifei Wang Jie Liu Yiyuan Zhang Peiqi Chu Haobin Liu Man Wang Erhong Duan
摘 要：Magnesia modified LaCoO3 was prepared by a facile one-step sol-gel method and used for removal of dilute methane.Compared with the conventional doping technique,the obtained LaCoO3@MgO-x exhibits pseudo core-shell structure and shows superior catalytic activity.The methane conversion exceeds90% at 532℃ on LaCoO3@MgO-0.1,while only 60% of methane is conversed using the doped perovskite LaCo0.9Mg0.1O3.The high catalytic performance of LaCoO3@MgO-0.1 is mainly attributed to the adjustment of surface acid-base properties by the MgO shell structure.According to density functional theory（DFT） calculation,the methane is more likely to be adsorbed and cracked on LaCoO3@MgO-0.1.The in situ DRIFTS shows that CH3-O-CH3 intermediate specie is formed.The pseudo core-shell structure also enhances the stability and the LaCoO3@MgO-0.1 maintains high activity after working for 100 h.The above results demonstrate that surface modification by magnesia is an effective strategy for improving LaCoO3 catalytic performance.
Saifei Wang，Jie Liu，Yiyuan Zhang，Peiqi Chu，Haobin Liu，Man Wang，Erhong Duan
School of Environmental Science and Engineering,Hebei University of Science and Technology
摘 要：Magnesia modified LaCoO3 was prepared by a facile one-step sol-gel method and used for removal of dilute methane.Compared with the conventional doping technique,the obtained LaCoO3@MgO-x exhibits pseudo core-shell structure and shows superior catalytic activity.The methane conversion exceeds90% at 532℃ on LaCoO3@MgO-0.1,while only 60% of methane is conversed using the doped perovskite LaCo0.9Mg0.1O3.The high catalytic performance of LaCoO3@MgO-0.1 is mainly attributed to the adjustment of surface acid-base properties by the MgO shell structure.According to density functional theory（DFT） calculation,the methane is more likely to be adsorbed and cracked on LaCoO3@MgO-0.1.The in situ DRIFTS shows that CH3-O-CH3 intermediate specie is formed.The pseudo core-shell structure also enhances the stability and the LaCoO3@MgO-0.1 maintains high activity after working for 100 h.The above results demonstrate that surface modification by magnesia is an effective strategy for improving LaCoO3 catalytic performance.
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