Hydrothermal Stability of Core-Shell Pd@Ce0.5Zr0.5O2/Al2O3 Catalyst for Automobile Three-Way Reaction
Hydrothermal Stability of Core-Shell Pd@Ce0.5Zr0.5O2/Al2O3 Catalyst for Automobile Three-Way Reaction
复制标题
汽车三元反应核壳Pd@Ce0.5Zr0.5O2/Al2O3催化剂的水热稳定性
DOI：
10.1021/acscatal.8b00358
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发表时间：
2018
期刊：
影响因子：
12.9
通讯作者：
He Hong
中科院分区：
文献类型：
--
作者：
Li Lingcong;Zhang Ningqiang;Huang Xing;Liu Ya;Li Yaoyao;Zhang Guizhen;Song Liyun;He Hong
本文考察了具有核壳结构的Pd@Ce0.5Zr0.5O2/Al_2O_3催化剂在汽车三效反应中的水热稳定性和催化活性，并与Pd/Al_2O_3、Pd@CeO_2/Al_2O_3、Pd@ZrO_2/Al_2O_3催化剂进行了比较。TEM、HRTEM和EDS图谱分析表明，经1050℃水热处理5h后，Pd@Ce0.5Zr0.5O2纳米粒子的核壳结构完好，CO漂移结果表明Pd核与Ce0.5Zr0.5O2壳层的界面是三效催化剂反应的活性中心。此外，XPS、FT-IR和CO漂移分析表明，Pd@Ce0.5Zr0.5O2/Al_2O_3催化剂表面存在大量的OH基团，可加速碳酸盐物种的分解，降低催化反应的活化能。这是Pd@Ce0.5Zr0.5O2/Al_2O_3催化剂在高温老化后仍能保持较高催化活性的重要原因。
In this paper, the hydrothermal stability and catalytic activity of Pd@Ce0.5Zr0.5O2/Al2O3catalyst with a core–shell structure were investigated for automobile three-way reactions and compared with those of Pd/Al2O3, Pd@CeO2/Al2O3, and Pd@ZrO2/Al2O3catalysts. TEM, HRTEM, and EDS mapping analyses showed that the core–shell structure of Pd@Ce0.5Zr0.5O2nanoparticles was intact after the hydrothermal treatment at 1050 °C for 5 h. Meanwhile, CO–DRIFT results suggested that the interface of Pd core and Ce0.5Zr0.5O2shell acted as the active sites in the reaction of three-way catalysts. Additionally, XPS, FT-IR, and CO–DRIFT analyses demonstrated that a large amount of OH groups were present on the surface of Pd@Ce0.5Zr0.5O2/Al2O3catalyst, which could accelerate the decomposition of carbonate species and reduce the activation energy of the catalytic reaction. This was an important reason for the Pd@Ce0.5Zr0.5O2/Al2O3catalyst to keep the high catalytic activity after aging at high temperature.