Skeletal isomerization of n-butane on zeolites and sulfated zirconium oxide promoted by platinum: Effect of reaction pressure

[[abstract]]The isomerization of n-butane catalyzed by sulfated zirconium oxide and H-form zeolites with the promotion of platinum has been studied by measurements of the conversion and product distribution at temperatures of 240 similar to 390 degrees C at atmospheric pressure and at 20.4 atm, The skeletal isomerization proceeds mainly via the bimolecular disproportionation mechanism on Pt/H-zeolite at 1 atm and via the monomolecular carbocation mechanism on Pt/SO42--ZrO2 at temperatures of less than or equal to 300 degrees C at both 1 and 20.4 atm, At 20.4 atm pressure, the monomolecular cracking and isomerization of butane can also occur on Pt/H-zeolite. Hydrogen molecules may be dissociated and converted to hydride and proton ions on Pt/SO42--ZrO2, promoting the desorption of surface carbenium ions and the cracking of butane molecules, which have been enhanced under high reaction pressures.[[fileno]]2010323010069[[department]]化學