Investigation of defect-rich CeO2 catalysts for super low-temperature catalytic oxidation and durable styrene removal

Ying Zhang; Liming Zhang; Jichang Lu; Wei Liao; Jin Zhang; Xiaoya Gao; Yongming Luo; Wenjie Zhu

doi:10.1016/j.chemosphere.2022.134863

Investigation of defect-rich CeO₂ catalysts for super low-temperature catalytic oxidation and durable styrene removal

Chemosphere. 2022 Sep;303(Pt 1):134863. doi: 10.1016/j.chemosphere.2022.134863. Epub 2022 May 10.

Authors

Ying Zhang¹, Liming Zhang¹, Jichang Lu¹, Wei Liao¹, Jin Zhang², Xiaoya Gao¹, Yongming Luo³, Wenjie Zhu⁴

Affiliations

¹ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, PR China; The Innovation Team for Volatile Organic Compounds Pollutants Control and Resource Utilization of Yunnan Province/The Higher Educational Key Laboratory for Odorous Volatile Organic Compounds Pollutants Control of Yunnan Province, Kunming, 650500, PR China.
² Yunnan University/Yunnan Key Laboratory of Micro/Nano Materials & Technology, Kunming, 650500, PR China.
³ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, PR China; The Innovation Team for Volatile Organic Compounds Pollutants Control and Resource Utilization of Yunnan Province/The Higher Educational Key Laboratory for Odorous Volatile Organic Compounds Pollutants Control of Yunnan Province, Kunming, 650500, PR China; Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650093, PR China. Electronic address: environcatalysis@kust.edu.cn.
⁴ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, PR China; The Innovation Team for Volatile Organic Compounds Pollutants Control and Resource Utilization of Yunnan Province/The Higher Educational Key Laboratory for Odorous Volatile Organic Compounds Pollutants Control of Yunnan Province, Kunming, 650500, PR China. Electronic address: zhuwenjie17@163.com.

PMID: 35561759
DOI: 10.1016/j.chemosphere.2022.134863

Abstract

Spherical cerium dioxide (CeO₂-S) nanoparticles were successfully prepared using a solvothermal method, and their performances in catalytic oxidation reactions were studied. The CeO₂-S catalyst showed superior low-temperature catalytic activity for styrene removal (T₉₀ = 118 °C, GHSV = 18,000 h^-1) compared with commercial CeO₂. The characterization results showed that there were numerous oxygen defects in CeO₂-S that were key to its catalytic performance at low temperatures, high redox properties, and high adsorption capacity for the reaction gases (O₂ and styrene). Moreover, the catalytic performance of CeO₂-S was highly stable (132 h), and the particles were reusable. FTIR and in-situ DRIFTS results showed that the type of intermediates formed during the oxidation of styrene determined the CeO₂ catalytic stability, and the main intermediates were bidentate carbonate species that accumulated on the surface of deactivated CeO₂-S and were not thermally stable. Moreover, the soft carbon that also deposited on CeO₂-S during the reaction was easily decomposed at higher temperatures. The role of the oxygen vacancies on the CeO₂-S catalyst was further revealed by correlating the concentration of oxygen vacancies and the accumulation of coke on the catalyst surface.

Keywords: Carbonate and coke resistance; Gaseous styrene; Low temperature catalytic oxidation; Oxygen vacancies; Spherical cerium dioxide.