Lewis acid sites commercial processes

It is seen that metal and metal oxide catalysts have significant roles in the catalyHc process for the production of fuels and chemicals. There are several catalysts that are used commercially in the biorefinery system to produce fuels and chemicals. Metal oxides are composed of cations possessing Lewis acid sites and anions wifh Br0nsted base sites. They are classified into single metal oxides and mixed metal oxides. Transition metal oxides have catalytic activity for cellulose hydrolysis, and when used as solid acid catalysts, they are reusable and thus may be easily separated from the reaction mixture. 

The peak shapes of metal chelating analytes are often poor because metal impurities in the stationary phase behave as active sites characterized by slowo desorption kinetics and higher interaction energies compared to reversed phase ligand sites. This phaiomaion is typical of silica-based stationary phases [31] ultrapure silicas were made commercially available to reduce it. However, styrene-divinylbenzene-based chromatogripliic packings suffer from the same problem and it was hypothesized that metals may be present in the matrix at trace conditions because they were used as additives in the polymerization process they may have been c tured via Lewis acid-base interactions between the aromatic ring n electrons and impurities in the mobile phase [32]. 

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