Statement of the problem

To eliminate benzoid compounds from petrol it should contain more iso-alkanes. It can be reached by additional treatment of regular petrol by sulphuric or hydrofluoric acids for catalytic isomerization of the n-alkanes. Many disadvantages related to the use of liquid catalysts have led to intensive research on solid catalysts with high acidity. Metal oxides and silicates treated by sulphuric acid are proposed as an alternative. They suffer in low stability (leaching), quick poisoning and low acidity.