Catalytic Vapor Phase Nitroxidation of p -Xylene: a New Route for Synthesis of Terephthalic Acid and Poly(ethylene Terephthalate)

Abstract

We have examined catalytic transformation of p-xylene into terephthalonitrile with nitric oxide (NO) over an aluminium oxide-supported ferric oxide catalyst using a fixed bed reactor in a temperature range of 320-460°c under atmospheric pressure. We achieved a maximum conversion of 80% with an Al₂O₃:Fe₂O₃ catalyst having an Al:Fe atomic ratio of nearly 1:1 at a temperature of 360°c with a NO:p-xylene mole ratio of 54.60. We studied the effect of temperature and NO:p-xylene mole ratio on the conversion to terephthalonitrile. Using Mössbauer and IR spectra of the catalysts, we concluded that Al₂O₃ not only provides a larger surface for the iron oxide catalyst, but also increases its activity by interacting with Fe₂O₃ and upholds the theory of metal support interaction.