Catalytic Mechanisms in Heterogeneous Oxidation Processes

Heterogeneous oxidation lies at the heart of many industrial and environmental applications, from exhaust‐gas treatment to fine chemical synthesis. Central to these processes is the interplay between gas‐phase oxidants and solid catalysts, where active sites on metal or metal‐oxide surfaces mediate adsorption, activate O₂ molecules and facilitate bond‐breaking and bond‐making steps. Two principal mechanistic frameworks often apply: Langmuir–Hinshelwood pathways, in which both reactants adsorb and react on adjacent sites, and Mars–van Krevelen cycles, where lattice oxygen participates directly in substrate oxidation and is subsequently replenished by gaseous oxygen. The catalytic performance depends sensitively on metal–support interactions, particle size and morphology, surface electronic structure and dynamic restructuring under reaction conditions. Recent advances in materials synthesis have enabled precise control of core–shell architectures, single‐atom sites and high‐entropy oxides. These developments have deepened understanding of the roles of ensemble effects, electronic ligand effects and dynamic site adaptation, leading to catalysts with enhanced activity, selectivity and durability. Practical applications include automotive emission control, selective oxidation of alcohols, volatile organic compound abatement and hydrogen production by reforming processes. Continued progress in in situ characterisation, theory and nanofabrication promises to unlock further gains in efficiency and sustainability.

Research from Nature Portfolio

Advances in bimetallic nanostructures have revealed how dual size effects can synergise activity in oxidation reactions. By precisely tuning the core diameter and shell thickness of Au@Pd core–shell catalysts, researchers have demonstrated record high rates for benzyl alcohol oxidation. Larger gold cores minimise lattice strain while an optimised palladium shell thickness ensures robust adsorption of reactants without overbinding, illustrating the delicate balance of geometrical and electronic factors. Meanwhile, theoretical investigations into higher tungsten boride (WB₅₋ₓ) surfaces have identified promising low‐energy pathways for CO oxidation. Density functional calculations coupled with Wulff‐shape predictions show that boron‐ and tungsten‐terminated facets offer differing adsorption strengths and charge redistribution characteristics, leading to low activation barriers. Together, these studies showcase the power of combining theory and precise synthesis to design next‐generation oxidation catalysts.

Catalytic Mechanisms in Heterogeneous Oxidation Processes publication trend

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

Technical terms

Langmuir–Hinshelwood mechanism: Reaction pathway in which both reactants adsorb concurrently on adjacent surface sites before undergoing surface‐mediated reaction.

Mars–van Krevelen mechanism: Oxidation mechanism involving lattice oxygen from the catalyst that oxidises the substrate and is then replenished by gaseous oxygen.

Core–shell catalyst: Nanostructure in which an inner ‘core’ material is enclosed by an outer ‘shell’, enabling fine‐tuning of strain and electronic effects.

Single‐atom catalyst: Catalyst featuring isolated metal atoms dispersed on a support, maximising atom efficiency and creating uniform active sites.

Wulff construction: Geometrical method to predict the equilibrium shape of a crystal or nanoparticle based on surface energy minimisation.

References

1. Conjugated dual size effect of core-shell particles synergizes bimetallic catalysis. Nature Communications (2023).
2. Theoretical study of adsorption properties and CO oxidation reaction on surfaces of higher tungsten boride. Scientific Reports (2024).
3. Cu–Au nanoparticles produced by the aggregation of gas‐phase metal atoms for CO oxidation. Aggregate (2022).
4. Highly Active and Stable Single Atom Rh1/CeO2 Catalyst for CO Oxidation during Redox Cycling. ChemCatChem (2023).