Catalytic Mechanisms in Amorphous Silica Systems

The catalytic performance of amorphous silica derives from its disordered network of Si–O bonds, surface silanol groups and inherent defect sites. In the absence of long‐range order, local variations in bond angles and ring sizes give rise to a spectrum of acidic and basic centres. Brønsted acidity emerges chiefly from isolated or vicinal silanol nests, enabling proton‐transfer processes, whereas Lewis acidity can be introduced via framework non‐bridging oxygens or through incorporation of metal ions and single‐atom species. Catalytic turnover typically proceeds by adsorption of reactant molecules into surface silanol cavities or mesopores, activation through protonation or electron withdrawal at defect sites, bond cleavage or rearrangement and subsequent desorption of products. Computational studies have revealed that active‐site heterogeneity strongly influences reaction pathways, while spectroscopic simulations have illuminated transition states within dynamic silica environments. Defect engineering—such as intentional creation of siloxane bridges or implantation of heteroatoms—has been shown to tune acidity, enhance selectivity and improve catalyst longevity. Practical applications range from biomass conversion and fine‐chemical synthesis to environmental remediation and energy storage, underlining the broad significance of understanding and controlling amorphous silica’s catalytic mechanisms.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Catalytic Mechanisms in Amorphous Silica Systems publication trend

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

Technical terms

Amorphous silica: A non‐crystalline form of silicon dioxide characterised by a disordered Si–O network without long‐range periodicity.

Silanol group: A surface functional moiety (Si–OH) that serves as a Brønsted acid or hydrogen‐bond donor in catalysis.

Brønsted acidity: Catalytic acidity arising from proton donors, facilitating reactions via protonation of adsorbed substrates.

Lewis acidity: Catalytic acidity derived from electron‐pair acceptors, often associated with metal centres or non‐bridging oxygens.

Active‐site heterogeneity: The existence of multiple, structurally distinct catalytic sites within the amorphous matrix that exhibit varied reactivity.

References

1. Recent Advances on Computational Modeling of Supported Single-Atom and Cluster Catalysts: Characterization, Catalyst–Support Interaction, and Active Site Heterogeneity. Catalysts (2024).