In this work, we present a systematic investigation of Ce-site-substituted mixed oxides to establish a rational strategy for enhancing oxygen release in ceria-based materials. By combining different classes of dopants in a fluorite CeO₂ lattice, we identify clear dopant synergy effects that significantly lower oxygen-release temperatures and improve catalytic combustion performance. We further demonstrate that a carefully designed quaternary oxide, CePrZrSmOx, achieves both the highest oxygen-release capacity and the best soot-combustion activity among all the materials investigated.
Key Insights
- Three dopant roles identified: reducible cations (Pr, Tb), lattice stabilizers (Zr, Ti), and oxygen-vacancy promoters (Sm, La).
- Distinct enhancement mechanisms: dopants improve oxygen release through redox participation, enhanced Ce reducibility, or accelerated oxygen diffusion.
- Synergy matters: combining dopants from different categories lowers oxygen-release temperatures more effectively than single-dopant systems.
- Best-performing composition: the quaternary oxide CePrZrSmOx exhibited the lowest oxygen-release temperature (~428 °C) and highest oxygen-release capacity (~1.4 mmol g⁻¹).
- Superior soot combustion: oxygen-release performance directly correlated with catalytic activity, with CePrZrSmOx achieving the lowest soot-combustion temperature (346 °C).
- Rational design strategy: dopant synergy provides a practical framework for developing advanced oxygen-storage and combustion catalysts.
Significance of This Work
We establish a dopant-synergy design principle for ceria-based mixed oxides by linking reducibility, lattice stabilization, and oxygen-vacancy formation to oxygen-release performance. The resulting quaternary oxide demonstrates how complementary dopant functions can be combined to achieve superior catalytic properties.
These findings offer a rational pathway for developing high-performance combustion catalysts for emissions control and environmental applications, while also providing broader insights into the design of multicomponent oxide materials.
Authors & Affiliations
Duanxing Li, Fang Zhang, Yuki Nakaya, and Shinya Furukawa*
Division of Applied Chemistry, Graduate School of Engineering, The University of Osaka, Suita 565-0871, Osaka, Japan.
Corresponding Author:
Prof. Shinya Furukawa
✉ furukawa@chem.eng.osaka-u.ac.jp
How to Cite This Article
Li, D. et al. (2026). Rational design of Ce-based mixed oxides via dopant synergy for enhanced oxygen release and combustion. Catal, 2, 15.