Bimetallic Catalysis in Selective Oxidation Processes

Bimetallic catalysis refers to catalysts composed of two distinct metal elements intimately combined at atomic or nanoscale, which can deliver superior activity and selectivity in selective oxidation processes. Selective oxidation is a class of reactions where specific bonds in a substrate are oxidised to yield desired oxygenated products such as aldehydes, ketones or epoxides, while minimising over-oxidation and by-product formation. The interplay between two metals modulates electronic structure, adsorption energies and reaction pathways, affording synergistic benefits unattainable with monometallic counterparts. Recent advances in synthesis have enabled precise control of composition, particle size, support interactions and surface atomic arrangements. Characterisation tools including X-ray absorption spectroscopy, electron microscopy and density functional theory calculations have elucidated active-site motifs—ranging from single-atom pairs to alloy clusters—and the role of metal-support synergy. Applications span from sustainable conversion of alcohols to fine chemicals, dehydrogenative aromatisation to phenols and gas-phase oxidations under mild conditions. Bimetallic systems such as Au–Pd, Pd–Cu and Au–Ag on oxide or carbonaceous supports are particularly prominent owing to their tunable d-band properties and resistance to sintering. Optimisation of composition and support architecture continues to unlock more efficient and environmentally benign oxidation processes with broad industrial and environmental impact.

Research from Nature Portfolio

Optimising the surface electronic properties of Au–Pd nanoalloy catalysts has yielded profound insights into the mechanism of primary alcohol oxidation. Monodisperse Au–Pd clusters embedded in mesoporous carbon were engineered with variable Pd–Au coordination, revealing that Pd single atoms and dimers act as the principal active sites. The surface d-orbital charge on Pd correlates directly with adsorbate binding strength and catalytic turnover, with compositions containing 33–50 at% Pd demonstrating up to nine-fold rate enhancements relative to pure Pd. These findings offer a rational descriptor for catalyst design and clarify the electronic ligand effects underpinning bimetallic synergy.

Bimetallic Catalysis in Selective Oxidation Processes publication trend

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

Technical terms

Bimetallic catalyst: A catalytic material comprising two metals combined at the nanoscale to exploit synergistic electronic and geometric effects.

Selective oxidation: A reaction that introduces oxygen into specific molecular sites, yielding desired oxygenated products while minimising complete oxidation to CO₂ or undesired by-products.

Turnover frequency (TOF): A measure of catalytic activity expressed as the number of substrate molecules converted per active site per unit time.

D-orbital charge: The electron density in the metal d orbitals, which influences adsorbate binding and catalytic activation barriers.

Synergistic effect: A phenomenon where the combined performance of two metals exceeds the sum of their individual activities due to electronic or structural interactions.

References

1. Boosting the Catalytic Performance of Au-Pd/Graphene Oxide Nanocomposites via the Controlled Oxidation of Graphene Sheets. Journal of Composites Science (2024).
2. Optimising surface d charge of AuPd nanoalloy catalysts for enhanced catalytic activity. Nature Communications (2019).
3. Au-Pd Bimetallic Nanocatalysts Incorporated into Carbon Nanotubes (CNTs) for Selective Oxidation of Alkenes and Alcohol. Processes (2020).
4. Catalytic Oxidation of Benzyl Alcohol to Benzaldehyde on Au8 and Au6Pd2 Clusters: A DFT Study on the Reaction Mechanism. Catalysts (2021).