Relationship between hydrothermal temperatures and structural properties of CeO2 and enhanced catalytic activity of propene/toluene/CO oxidation by Au/CeO2 catalysts

Srisin Eaimsumang; Nuwong Chollacoop; Apanee Luengnaruemitchai; Stuart H Taylor

doi:10.3389/fchem.2022.959152

Relationship between hydrothermal temperatures and structural properties of CeO₂ and enhanced catalytic activity of propene/toluene/CO oxidation by Au/CeO₂ catalysts

Front Chem. 2022 Sep 21:10:959152. doi: 10.3389/fchem.2022.959152. eCollection 2022.

Authors

Srisin Eaimsumang¹, Nuwong Chollacoop², Apanee Luengnaruemitchai^{1

3}, Stuart H Taylor⁴

Affiliations

¹ The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand.
² Renewable Energy Laboratory, National Energy Technology Center (ENTEC), Pathumthani, Thailand.
³ Center of Excellence in Catalysis for Bioenergy and Renewable Chemicals, Chulalongkorn University, Bangkok, Thailand.
⁴ Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, United Kingdom.

Abstract

A simple hydrothermal synthesis of CeO₂ was implemented to obtain a series of CeO₂-supported gold (Au) catalysts, used for the total oxidation of propene/toluene/CO gas mixtures and the oxidation of CO. CeO₂ preparation started from a cerium hydrogen carbonate precursor using a range of different hydrothermal temperatures (HT) from 120 to 180°C. High-resolution transmission electron microscopy, X-ray diffraction, and H₂-temperature-programmed reduction data indicated that CeO₂ morphology varied with the HT, and was composed of the more active (200) surface. Following Au deposition onto the CeO₂ support, this active crystal plane resulted in the most widely dispersed Au nanoparticles on the CeO₂ support. The catalytic performance of the CeO₂-supported Au catalysts for both oxidation reactions improved as the reducibility increased to generate lattice oxygen vacancies and the number of adsorbed peroxide species on the CeO₂ support increased due to addition of Au. The Au catalyst on the CeO₂ support prepared at 120°C was the most active in both propene/toluene/CO oxidation and independent CO oxidation.

Keywords: VOCs; ceria; gold; morphology; oxidation.