Constructing Pt/ZnO@SiO2 composite structures to enhance the thermal stability and CO oxidation activity of Pt-based catalysts--颗粒学报PARTICUOLOGY

a School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
b Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
c Department of Chemical Engineering, Qufu Normal University, Qufu, 273165, China
d School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun, 113001, China
e Hydrogen and Ammonium Energy R&D Center, National Institute of Clean-and-Low-Carbon Energy, Beijing, 102211, China

10.1016/j.partic.2025.02.023

Volume 100, May 2025, Pages 36-44

Received 16 February 2025, Revised 28 February 2025, Accepted 28 February 2025, Available online 13 March 2025, Version of Record 20 March 2025.

E-mail: lyzhang2019@qfnu.edu.cn; bszhang@imr.ac.cn

Highlights

• The SiO₂ layer effectively restrains Pt nanoparticle sintering during high-temperature calcination.

• The SiO₂ coated on Pt-based catalyst enhances the oxidation activity and stability of low-temperature CO oxidation.

• The SiO₂ layer is cost-effective and readily available.

Abstract

The catalytic oxidation of carbon monoxide (CO) to carbon dioxide (CO₂) is an effective way to eliminate the harmful effects of CO, with catalysts playing a crucial role in this process. Although Pt-based catalysts have been widely used for CO oxidation, the low-temperature activity and thermal stability still need to be improved. In this study, a Pt/ZnO@SiO₂ composite structure was constructed by coating Pt/ZnO catalysts with a thin SiO₂ layer. The influence of SiO₂ overcoating layer on the sintering behavior of Pt nanoparticles (NPs) and on the catalytic performance of the Pt catalyst for CO oxidation was investigated in detail. And the results were compared with those without SiO₂ overcoating layer. Investigations found that the SiO₂ coating layer effectively inhibited the sintering of Pt NPs at high temperatures, enhancing the thermal stability. In addition, the SiO₂ overcoating layer improved the catalytic activity of the Pt-based catalyst by inducing higher concentration of oxygen vacancies on the catalyst surface as well as weakening the CO adsorption, which could enhance the adsorption and activation ability of oxygen. Meanwhile, the presence of SiO₂ overcoating layer improved the catalytic stability during CO oxidation reaction. This work provides an important reference for the design and development of supported Pt-based catalysts with excellent thermal stability and catalytic activity for CO oxidation.

Graphical abstract

Keywords

Pt catalysts; SiO₂; Overcoating layer; Thermal stability; CO oxidation

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