Catalytic Epoxidation Processes in Propylene Oxidation

The epoxidation of propylene to produce propylene oxide is a cornerstone of modern chemical manufacturing, underpinning the production of polyurethane, polyether polyols and a variety of fine chemicals. Catalytic approaches typically employ hydrogen and oxygen in the gas phase, with gold-based catalysts demonstrating exceptional potential in terms of activity and selectivity. Key developments have centred on tuning the size and oxidation state of gold species, from sub-nanometre clusters to single-atom catalysts, and on designing supports that promote optimal electronic interactions and intermediate stabilisation. Mechanistic studies, combining kinetics, in situ spectroscopy and multiscale modelling, have identified the formation and consumption of hydroperoxyl species as critical steps, and have elucidated descriptors for matching rates of reactant activation. Challenges remain in mitigating catalyst deactivation by carbonaceous poisoning, enhancing long-term stability and suppressing side-reactions such as over-oxidation or isomerisation. Advances in support engineering, photocatalytic variants and self-healing catalyst architectures are shaping a new generation of robust and efficient systems with significant industrial and environmental impact.

Research from Nature Portfolio

Recent studies have explored the synergy between gold single-atom sites and gold nanoparticles, demonstrating that trace additions of nanoparticles act as an antidote to poisoning of single-atom catalysts. By providing complementary active centres for H₂/O₂ and C₃H₆ activation and by regenerating hydroperoxyl intermediates, the dual-site system achieves matched reaction orders and sustained epoxidation rates. This approach yields substantial improvements in propylene oxide formation rate, selectivity and hydrogen efficiency, while maintaining stability over extended operation. The findings illustrate a paradigm in which multi-scale active sites collaborate to overcome deactivation and to optimise intermediate flux, pointing towards scalable and durable epoxidation catalysts.

Catalytic Epoxidation Processes in Propylene Oxidation publication trend

The graph below shows the total number of articles in catalytic epoxidation processes in propylene oxidation across all publications each year (not limited to Nature Index journals).

Technical terms

Epoxidation: Addition of an oxygen atom across a carbon–carbon double bond to form a three-membered epoxide ring.

Single-Atom Catalyst (SAC): A catalyst in which individual metal atoms are isolated on a support, maximising metal utilisation and unique reactivity.

Hydroperoxyl Radical: Reactive intermediate (•OOH) generated from H₂ and O₂, crucial for oxygen transfer and catalyst self-regeneration.

Titanosilicate: A silica-titania framework support that forms active Ti-OOH species and anchors gold clusters for selective oxidation.

Propylene Oxide: Epoxide product of propylene oxidation, serving as a key intermediate for polymers and speciality chemicals.

References

1. Nanoparticles as an antidote for poisoned gold single-atom catalysts in sustainable propylene epoxidation. Nature Communications (2024).
2. Theoretical Studies on the Direct Propylene Epoxidation Using Gold-Based Catalysts: A Mini-Review. Catalysts (2018).
3. Recent Advances in Selective Photo-Epoxidation of Propylene: A Review. Catalysts (2020).
4. Theoretical Investigation of Propylene Epoxidation Using H2 and O2 Over Titanosilicate-Supported Au Catalysts. Catalysis Letters (2024).
5. Influence of the Support on Propene Oxidation over Gold Catalysts. Catalysts (2022).
6. Performance, Reaction Pathway, and Pretreatment of Au Catalyst Precursor in H2/O2 Atmosphere for the Epoxidation of Propylene. Catalysts (2022).