Heterogeneous Catalysis in Liquid-Phase Reactions

Heterogeneous catalysis in liquid-phase reactions underpins a wide array of industrial and environmental processes, ranging from fine chemical synthesis to biomass conversion and fuel production. In these systems, a solid catalyst provides active sites at its surface or within its porous structure, while reactants and products reside in a surrounding liquid medium. The interplay between catalyst surface properties, solvent interactions and mass-transport phenomena governs activity, selectivity and durability. Solvents can influence adsorption equilibria, stabilise key reaction intermediates, alter transition-state energies and mediate proton or electron transfer. The architecture of the solid–liquid interface thus becomes central to catalyst design, demanding integrated approaches that combine advanced characterisation under working conditions with theoretical modelling. Recent advances have focused on tuning catalyst composition and morphology to optimise liquid-phase performance, exploiting electrochemical potentials to drive novel pathways, and deploying explicit solvation models to predict and control reaction energetics. Together, these efforts aim to forge more efficient, selective and sustainable catalytic processes for the production of fuels, commodity chemicals and pharmaceuticals.

Research from Nature Portfolio

Recent studies have shown that the open-circuit potential established at a catalyst–liquid interface can modulate reaction energetics and accelerate hydrogenolysis rates in aqueous media. In particular, investigations of hydrogenation over palladium on carbon demonstrated a two to three orders of magnitude increase in benzylic alcohol conversion as pH is lowered, attributed to electrostatic stabilisation of cationic intermediates and transition states. Application of an external negative potential in an electrochemical cell further amplified hydride‐transfer steps, pointing to hybrid electrocatalytic strategies for improved selectivity and energy efficiency. Complementary computational work employing hybrid quantum mechanical/molecular mechanical simulations has revealed that solvation effects in water vary strongly with metal identity, impacting activation free energies for C–H and O–H bond cleavage in surface reactions. These findings underscore the necessity of explicit solvent modelling and metal‐specific design rules for catalysts operating in liquid-phase environments.

Heterogeneous Catalysis in Liquid-Phase Reactions publication trend

The graph below shows the total number of articles in heterogeneous catalysis in liquid-phase reactions across all publications each year (not limited to Nature Index journals).

Technical terms

Heterogeneous catalysis: A catalytic process in which the catalyst is in a different phase (typically solid) from the reactants (liquid), with reactions occurring at the solid–liquid interface.

Solid–liquid interface: The boundary region where a solid catalyst contacts the liquid reaction medium, characterised by unique adsorption and solvation phenomena.

Open circuit potential (OCP): The equilibrium electrochemical potential at an electrode–electrolyte interface in the absence of an external current, which can stabilise or destabilise charged intermediates.

Solvation effect: The influence of solvent molecules on reactant, intermediate or product stability and mobility, affecting reaction rates and selectivity in liquid-phase catalysis.

Adsorption: The process by which reactant molecules or intermediates bind to active sites on the catalyst surface, a key step in heterogeneous catalytic cycles.

References

1. Importance of interface open circuit potential on aqueous hydrogenolytic reduction of benzyl alcohol over Pd/C. Nature Communications (2022).
2. Dependency of solvation effects on metal identity in surface reactions. Communications Chemistry (2020).
3. Poisoning of Pt/γ-Al2O3 Aqueous Phase Reforming Catalysts by Ketone and Diketone-Derived Surface Species. ACS Catalysis (2024).
4. Spontaneous Charge Separation at the Metal‐Water Interface. ChemPhysChem (2024).