Related Experiment Video
Updated: Feb 4, 2026

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica
Published on: July 9, 2015
Size-Dependent Catalytic Activity of Oxo-Hydroxo Titanium Sub-Nanoislets Grafted on Organically Modified Mesoporous
Lin Fang1,2, Belén Albela1,2, Boting Yang2
1Laboratoire de Chimie, Ecole Normale Supérieure de Lyon , Université de Lyon , 46 Allée d'Italie , 69364 Lyon Cedex 07, France.
Abstract:
The reaction between titanium alkoxides, [Ti(OR)4], and surface silanol groups is widely used to generate grafted oxo-hydroxo titanium species, whose size is difficult to control. Partial capping of the surface silanols in the presence of the masking pattern of self-repelling tetramethylammonium ions allows us to isolate surface silanol islets, on which isolated titanium ions and dimeric oxo titanium species can be generated up to 2 Ti/Si mol %. Above this loading, and up to ∼8 Ti/Si mol %, higher oligomers (trimers, hexamers, octamers, and so on) are formed, reaching the size obtained at much lower loadings (<1 Ti/Si mol %) on a nonmodified silica surface. The downsizing effect produced on our organically modified surface is monitored from the blue-shift of the charge-transfer band of the Ti(IV) ions, measured by reflectance UV-visible spectroscopy. It is also mirrored by a higher catalytic activity in cyclohexene epoxidation, revealing that it is not only the isolated Ti species that are active but also the oligomers. Regarding the latter, the smaller they are, the more active they are.
More Related Videos
13:00Low Molecular Weight Protein Enrichment on Mesoporous Silica Thin Films for Biomarker Discovery
Published on: April 17, 2012
13:11Using Flexible Gold-Titanium Reaction Cells to Simulate Pressure-Dependent Microbial Activity in the Context of Subsurface Biomining
Published on: October 5, 2019
Related Concept Videos
Cell Size
Surface Area
Cells can take in nutrients and water via diffusion through the plasma membrane itself or through specific channels in the membrane. The area of the membrane surrounding...
Genome Size and the Evolution of New Genes
Turnover Number and Catalytic Efficiency
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
Catalytically Perfect Enzymes
Most enzymes...
tRNA Activation
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...