Water-Zeolite Interfaces for Controlling Reaction Routes in Fischer- Tropsch Synthesis of Alternative Fuels

Background: The Fischer-Tropsch Synthesis (FTS) remains an important process for motor fuel production from CO and H2. The composition of the FTS products (hydrocarbon mixtures) depends on the properties of a catalyst and on the process conditions. Summary: The introduction of zeolites into catalytic systems can alter the molecular weight distribution paving the way to tailor-made fuels, as was revealed by recent research results produced in the laboratories worldwide. The AlO4 and SiO4 tetrahedrons, which constitute the zeolites, are able to transfer electrons and ions in a way, which makes water-zeolite interfaces capable of initiating active carbonium ions. It was shown in a number of works that the water-zeolite interface plays a key role in diverting the FTS from the classical route. Conclusion: This review gives a critical analysis of literature data on the role of water-zeolite interfaces on FTS cobalt catalysts and on the interactions of hydrophobic and hydrophilic zeolites with water.

Skeletal Rearrangements of Rings C and D of the Kaurene and Beyerene Tetracyclic Diterpenoids

The skeletal rearrangement of the bicyclo[3.2.1]octane portion of rings C and D of the kaurene and beyerene tetracyclic diterpenoids are reviewed, revealing the tendency of the secondary carbocations to rearrange to tertiary carbocations with the eventual preferential formation of bicyclo[2.2.2]octanes. Under acid-catalysed conditions the variations in the products with the nucleophilicity of the counter ions suggest that the intervention of discrete rather than completely delocalised non-classical carbonium ions may be contributing to the reaction pathway.

Micromixing enhanced synthesis of HRPIBs catalyzed by EADC/bis(2-chloroethyl)ether complex

Better mixing could produce more active centers to accelerate the polymerization by promoting the consumption of carbonium ions.