Action of Salt Formation on the Bifunctional Nature of 12- Molybdophosphoric Acid and Their Relationship to the Catalytic Activity

Acidic properties and the catalytic activity of 12-molybdophosphates (M"nn+H3-,PM012040; M = Cu2+, BP+, Cr3+ and X = 1-3) have been studied. The results are discussed as the effect of these catalyst components on the partial charge on oxygen atom which is in a relation with the acidity. It is shown that the oxygen-hydrogen bond is weakened as the value of partial charge on oxygen (-bo) becomes more negative, while the vapor-phase dehydration activity of 2 propanol is explained on the basis of the reacting zone wideness taking into account the pseudo liquid phase nature of the heteropoly compounds. Correlation, the percentage conversion of 2-propanol with the fractional charge on molybdenum atom was successful to interpret the effect of the redox properties of these catalysts on their catalytic activity

Texture Studies on Chromium Oxide Doped Catalysts

Physisorption of N 2 gas at 77 K has been used to determine the surface area (SBET) and porosity of Cr 2 O 3 impregnated with Li 2 O in molar ratios extending from 0.25 to 50 mol %. Calcination of catalysts was affected in air flow in temperature range of 473-773 K. Variation of the SBET-calcination temperature relationship was interpreted according to the possible lattice rearrangements via a solid-state reaction leading to Li 2 CrO 4 phase formation for Li 2 O rich samples and by creation of cation vacancies in case of Li 2 O trace samples. The cumulative calculations together with Va-t plots showed a mesoporous surface nature of samples