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Large‐Pore Mesoporous CeO 2 –ZrO 2 Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation
Author(s) -
Yang Xuanyu,
Cheng Xiaowei,
Ma Junhao,
Zou Yidong,
Luo Wei,
Deng Yonghui
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201903058
Subject(s) - mesoporous material , materials science , catalysis , chemical engineering , nanoparticle , polystyrene , mesoporous organosilica , nanotechnology , mesoporous silica , chemistry , polymer , organic chemistry , composite material , engineering
Abstract Active and stable catalysts are highly desired for converting harmful substances (e.g., CO, NO x ) in exhaust gases of vehicles into safe gases at low exhaust temperatures. Here, a solvent evaporation–induced co‐assembly process is employed to design ordered mesoporous Ce x Zr 1− x O 2 (0 ≤ x ≤ 1) solid solutions by using high‐molecular‐weight poly(ethylene oxide)‐ block ‐polystyrene as the template. The obtained mesoporous Ce x Zr 1− x O 2 possesses high surface area (60–100 m 2 g −1 ) and large pore size (12–15 nm), enabling its great capacity in stably immobilizing Pt nanoparticles (4.0 nm) without blocking pore channels. The obtained mesoporous Pt/Ce 0.8 Zr 0.2 O 2 catalyst exhibits superior CO oxidation activity with a very low T 100 value of 130 °C (temperature of 100% CO conversion) and excellent stability due to the rich lattice oxygen vacancies in the Ce 0.8 Zr 0.2 O 2 framework. The simulated catalytic evaluations of CO oxidation combined with various characterizations reveal that the intrinsic high surface oxygen mobility and well‐interconnected pore structure of the mesoporous Pt/Ce 0.8 Zr 0.2 O 2 catalyst are responsible for the remarkable catalytic efficiency. Additionally, compared with mesoporous Pt/Ce x Zr 1− x O 2 ‐s with small pore size (3.8 nm), ordered mesoporous Pt/Ce x Zr 1− x O 2 not only facilitates the mass diffusion of reactants and products, but also provides abundant anchoring sites for Pt nanoparticles and numerous exposed catalytically active interfaces for efficient heterogeneous catalysis.