Single and composite bifunctional catalysts of H-MOR or SO42--ZrO2 for n-octane hydroisomerization-cracking. Influence of the porosity of the acid component

The performances of two materials with different acidic and textural properties, H-Mordenite and SO42--ZrO2, are compared in the hydroisomerization-cracking of n-octane at 573 K and 1.5 MPa, aiming at the production of light isomers. To obtain a bifunctional catalyst, a metallic function (Pt or Pd) is added either to the acid material or in a composite catalyst prepared by mixing the acid materials with either metal/SiO2 or metal/Al2O3. The synergy of functions produces catalysts more selective to isomers. Since the deactivation by pore blockage decreases, the composite catalysts with H-Mordenite present an improved stability. The composite catalysts with SO42--ZrO2 do not present this improvement because of their wide pore size distribution. (C) 1997 Elsevier Science B.V.