[1] J. Yang, H. Ding, J. Wang, N. Yigit, J. Xu, G. Rupprechter, M. Zhang, Z. Li, Energy-Guided Shape Control Towards Highly Active CeO2, Topics in Catalysis, (2020). https://doi.org/10.1007/s11244-020-01357-1

Energy-guided Shape Control Towards Highly Active CeO₂

Jingxia Yang^1,2,3, Huihui Ding¹, Jinjie Wang¹, Nevzat Yigit³, Jingli Xu¹, Günther Rupprechter³,
Min Zhang¹*, Zhiquan Li²*

Abstract

The shape of nanosized CeO₂, obtained via polyvinylpyrrolidone (PVP) micelles, was controlled by microwave (MW)-aided synthesis combined with different combinations of energy input/transfer, including ultrasound (US), ultraviolet (UV) and pressure (P). Whereas ceria nanoflakes resulted from standard solvothermal synthesis, CeO₂ nanoparticles were obtained from MW, MW+US and MW+UV. New CeO₂ “nanospindles” (with aspect ratio of 2) resulted from MW+US+UV, and nanorods (with aspect ratio of 11) emerged from MW+P.  All ceria morphologies, even nanospindles and nanorods, were mesoporous agglomerates of small CeO₂ nanocrystals (6-8 nm size), but they still exhibited different specific surface area (SSA) and Ce³⁺/Ce⁴⁺ ratio. Underlying reasons of how the different synthesis routes affect the ceria morphology are discussed. Among the six types, CeO₂ nanorods (MW+P) exhibited the highest SSA (196 m²g^-1) and the most surface defects (Ce³⁺: 26.4%), resulting in excellent catalytic performance in imine synthesis and CO oxidation.

Key words: Catalysts; CeO₂; CO oxidation; imine synthesis; microwave-assisted synthesis; shape and morphology control