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Effects of Zr substitution on soot combustion over cubic fluorite-structured nanoceria: Soot-ceria contact and interfacial oxygen evolution.
Liu, Peng; Liang, Xiaoliang; Dang, Yanliu; He, Junkai; Shirazi-Amin, Alireza; Achola, Laura A; Dissanayake, Shanka; Chen, Hanlin; Fu, Mingli; Ye, Daiqi; Suib, Steven L.
Afiliação
  • Liu P; School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA; University of Chinese Academy of Sciences, Beijing 100049, China.
  • Liang X; CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: lian
  • Dang Y; Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA.
  • He J; Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA.
  • Shirazi-Amin A; Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA.
  • Achola LA; Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA.
  • Dissanayake S; Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA.
  • Chen H; Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China.
  • Fu M; School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
  • Ye D; School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
  • Suib SL; Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA; Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA. Electronic address: steven.suib@uconn.edu.
J Environ Sci (China) ; 101: 293-303, 2021 Mar.
Article em En | MEDLINE | ID: mdl-33334524
ABSTRACT
Ceria is widely used as a catalyst for soot combustion, but effects of Zr substitution on the reaction mechanism is ambiguous. The present work elucidates effects of Zr substitution on soot combustion over cubic fluorite-structured nanoceria. The nanostructured CeO2, Ce0.92Zr0.08O2, and Ce0.84Zr0.16O2 composed of 5-6 nm crystallites display Tm-CO2 (the temperature at maximum CO2 yield) at 383, 355, and 375°C under 10 vol.% O2/N2, respectively. The size of agglomerate decreases from 165.5 to 51.9-57.3 nm, which is beneficial for the soot-ceria contact. Moreover, Zr increases the amount of surface oxygen vacancies, generating more active oxygen (O2- and O-) for soot oxidation. Thus, the activities of Ce0.92Zr0.08O2 and Ce0.84Zr0.16O2 in soot combustion are better than that of CeO2. Although oxygen vacancies promote the migration of lattice O2-, the enriched surface Zr also inhibits the mobility of lattice O2-. Therefore, the Tm-CO2 of Ce0.84Zr0.16O2 is higher than that of Ce0.92Zr0.08O2. Based on reaction kinetic study, soot in direct contact with ceria preferentially decomposes with low activation energy, while the oxidation of isolated soot occurs through diffusion with high activation energy. The obtained findings provide new understanding on the soot combustion over nanoceria.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cério / Fuligem Idioma: En Ano de publicação: 2021 Tipo de documento: Article
Texto completo
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PubMed Links
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Cério / Fuligem Idioma: En Ano de publicação: 2021 Tipo de documento: Article