yksittäiskatalyyttejä

Yksittäiskatalyytit, or single-site catalysts, are a class of catalysts where the active catalytic centers are isolated and well-defined at the atomic or molecular level. Unlike traditional heterogeneous catalysts, which often consist of nanoparticles or ensembles of active atoms, single-site catalysts feature individual, dispersed active sites on a support material. This precise control over the number and nature of active sites allows for a high degree of selectivity and efficiency in chemical reactions.

The development of single-site catalysts has been driven by the desire to understand and mimic the behavior of homogeneous catalysts in heterogeneous systems. By anchoring individual catalytic species onto a solid support, researchers aim to combine the benefits of homogeneous catalysis, such as high activity and selectivity due to well-defined active sites, with the advantages of heterogeneous catalysis, including ease of separation and recycling.

Common support materials for single-site catalysts include metal oxides, zeolites, mesoporous silica, and polymers. The active sites can be metal atoms, metal complexes, or organic functional groups. Methods for preparing single-site catalysts include impregnation, sol-gel synthesis, grafting, and deposition-precipitation.

Single-site catalysts have shown promise in a wide range of applications, including polymerization, oxidation, hydrogenation, and C-C coupling reactions. Their well-defined nature allows for a deeper understanding of reaction mechanisms at the molecular level, which can guide the design of even more efficient and selective catalysts. The controlled dispersion of active sites also minimizes metal leaching and deactivation, contributing to catalyst longevity.