Catalysts of self-assembled Pt@CeO2-δ-rich core-shell nanoparticles on 3D ordered macroporous Ce1-xZrxO2for soot oxidation: nanostructure-dependent catalytic activity.
The catalytic performance in heterogeneous catalytic reactions consisting of solid reactants is strongly dependent on the nanostructure of the catalysts. Metal-oxides core-shell (MOCS) nanostructures have potential to enhance the catalytic activity for soot oxidation reactions as a result of optimizing the density of active sites located at the metal-oxide interface. Here, we report a facile strategy for fabricating nanocatalysts with self-assembled Pt@CeO2-δ-rich core-shell nanoparticles (NPs) supported on three-dimensionally ordered macroporous (3DOM) Ce1-xZrxO2via the in situ colloidal crystal template (CCT) method. The nanostructure-dependent activity of the catalysts for soot oxidation were investigated by means of SEM, TEM, H2-TPR, XPS, O2-isothermal chemisorption, soot-TPO and so on. A CeO2-δ-rich shell on a Pt core is preferentially separated from Ce1-xZrxO2precursors and could self-assemble to form MOCS nanostructures. 3DOM structures can enhance the contact efficiency between catalysts and solid reactants (soot). Pt@CeO2-δ-rich core-shell nanostructures can optimize the density of oxygen vacancies (Ov) as active sites located at the interface of Pt-Ce1-xZrxO2. Remarkably, 3DOM Pt@CeO2-δ-rich/Ce1-xZrxO2catalysts show super catalytic performance and strongly nanostructure-dependent activity for soot oxidation in the absence of NO and NO2. For example, the T50of the 3DOM Pt@CeO2-δ-rich/Ce0.8Zr0.2O2catalyst is lowered down to 408 °C, and the reaction rate of the 3DOM Pt@CeO2-δ-rich/Ce0.2Zr0.8O2catalyst (0.12 μmol g-1s-1) at 300 °C is 4 times that of the 3DOM Pt/Ce0.2Zr0.8O2catalyst (0.03 μmol g-1s-1). The structures of 3DOM Ce1-xZrxO2-supported Pt@CeO2-δ-rich core-shell NPs are decent systems for deep oxidation of solid reactants or macromolecules, and this facile technique for synthesizing catalysts has potential to be applied to other element compositions.
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Yuechang
Y
Wei
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Jinqing
J
Jiao
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Xindong
X
Zhang
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Baofang
B
Jin
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn and Institute of Catalysis for Energy and Environment, Shenyang Normal University, Shenyang 110034, China.
Zhen
http://orcid.org/0000-0003-0044-5512
Z
Zhao
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Jing
J
Xiong
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Yazhao
Y
Li
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Jian
http://orcid.org/0000-0003-3392-9812
J
Liu
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, 18# Fuxue Road, Chang Ping District, Beijing, 102249, China. zhenzhao@cup.edu.cn zhaozhen@synu.edu.cn.
Jianmei
J
Li