Distribution of open sites in Sn-Beta zeolite

Competitive Adsorption of Substrate and Solvent in Sn‐Beta Zeolite During Sugar Isomerization

The isomerization of 1,3-dihydroxyactone and d-glucose over Sn-Beta zeolite was investigated by in situ 13 C NMR spectroscopy. The conversion rate at room temperature is higher when the zeolite is dehydrated before exposure to the aqueous sugar solution. Mass transfer limitations in the zeolite micropores were excluded by comparing Sn-Beta samples with different crystal sizes. Periodic density ...

Role of Silanol Group in Sn-Beta Zeolite for Glucose Isomerization and Epimerization Reactions

Density functional calculations are used to elucidate the role of the silanol group adjacent to the active site Sn metal center of the Sn-BEA zeolite in the isomerization and epimerization of glucose. We find that the silanol group plays an important role in the isomerization reaction, wherein hydride transfer and subsequent proton transfer occur in a single step with a lower energy of activati...

Dynamic nuclear polarization NMR enables the analysis of Sn-Beta zeolite prepared with natural abundance ¹¹⁹Sn precursors.

The catalytic activity of tin-containing zeolites, such as Sn-Beta, is critically dependent on the successful incorporation of the tin metal center into the zeolite framework. However, synchrotron-based techniques or solid-state nuclear magnetic resonance (ssNMR) of samples enriched with (119)Sn isotopes are the only reliable methods to verify framework incorporation. This work demonstrates, fo...

Decay factors and patterns of stones in open-air historical sites built of carbonate sedimentary stones

The number of historical open-air sites built of stone are relatively limited in comparison to the other historical artificial in Iran, but these sites include great significance in terms of value, historic and their knowledge of past. Since these stone poen-air sites are generally about two thousand years old, they have been exposed to decay factors for a long time. Many information and data o...

Dynamic Nuclear Polarization NMR Enables the Analysis of Sn-Beta Zeolite Prepared with Natural Abundance 119Sn Precursors