Catalytic Mechanisms in Cerium Oxide Systems

Ceria (CeO2) is a reducible oxide valued for its oxygen storage capacity and redox flexibility, finding applications in automotive-exhaust treatment, fuel-cell catalysis, gas sensing and environmental remediation. Catalytic mechanisms in ceria systems derive from the ability of the Ce4+/Ce3+ couple to mediate oxygen exchange and create surface defects such as oxygen vacancies. Metal–ceria interactions, particularly with platinum group metals, leverage these defects to activate small molecules via lattice oxygen transfer. At the atomic scale, single-atom catalysts and subnanometric clusters on ceria exhibit distinct pathways for reactant adsorption, activation and product desorption. Understanding the fluxional behaviour, coordination environments and facet-dependent effects of ceria supports underpins the design of efficient catalysts for global challenges in energy and environment.

Research from Nature Portfolio

Recent studies have elucidated the dynamic interplay between metal atoms and the ceria support at the atomic scale. Investigations into single-atom platinum on ceria demonstrate that the initial coordination environment dictates reactivity and memory effects during redox cycles, influencing cluster formation and catalytic turnover in CO oxidation. Fine-tuning the local coordination of Pt single atoms by controlled calcination reveals that distinct Pt–O bond configurations at terrace and edge sites afford reversed activity trends in oxidation reactions by governing reactant activation and product desorption. Operando electron microscopy has further shown that fluxional behaviour at Pt–CeO2 interfaces under reaction conditions drives oxygen vacancy creation and annihilation, with the interfacial Pt–O–Ce bonds mediating lattice oxygen transfer and enhancing low-temperature activity.

Catalytic Mechanisms in Cerium Oxide Systems publication trend

The graph below shows the total number of articles in catalytic mechanisms in cerium oxide systems across all publications each year (not limited to Nature Index journals).

Technical terms

Single-atom catalyst: A catalyst in which individual metal atoms are dispersed on a support to maximise atomic efficiency and unique reactivity.

Oxygen vacancy: A defect site in the ceria lattice where an oxygen atom is missing, which enhances redox activity by providing sites for reactant adsorption and activation.

Lattice oxygen: Oxygen atoms that are part of the crystal framework of ceria, capable of participating directly in oxidation reactions.

Fluxional behaviour: The dynamic rearrangement of atoms or bonds at the catalyst surface under reaction conditions, affecting active site structure and reactivity.

Mars-van-Krevelen mechanism: A reaction pathway in which lattice oxygen is consumed in oxidation and subsequently replenished by gas-phase oxygen.

References

1. Memory-dictated dynamics of single-atom Pt on CeO2 for CO oxidation. Nature Communications (2023).
2. Fine-tuned local coordination environment of Pt single atoms on ceria controls catalytic reactivity. Nature Communications (2022).
3. Atomic level fluxional behavior and activity of CeO2-supported Pt catalysts for CO oxidation. Nature Communications (2021).
4. Crystal Face‐Dependent Behavior of Single‐Atom Pt: Construct of SA‐FLP Dual Active Sites for Efficient NO2 Detection. Advanced Science (2024).
5. Enhanced degradation of micropollutants by visible light photocatalysts with strong oxygen activation ability. Water Research (2023).
6. CO oxidation activity of Pt/CeO2 catalysts below 0 °C: platinum loading effects. Applied Catalysis B Environment and Energy (2021).