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In order to solve the serious leaching problem of supported heteropoly acid catalysts in polar reaction media,12-molybdophosphoric acid encapsulated in the supercage of Cs+-exchanged Y zeolite was prepared by the “ship in the bottle” synthesis.The influence of ion-exchange conditions and the synthesis parameters on the encapsulation of PMo12 were investigated.The obtained solid sample was characterized by X-ray diffraction(XRD),31P magic angle spin nuclear magnetic resonance(MAS NMR) and Fourier Transform Infrared Spectroscopy(FT-IR),and its catalytic activity in the esterification of acetic acid and n-butanol was tested.The ion-exchange time,concentration of aqueous Cs+ solution,pH value,and amount of Mo added in the synthesis mixture were revealed to influence the encapsulation very remarkably.Under the optimal conditions,12-molybdophosphoric acid could be successfully encapsulated in the supercage of CsY zeolite,and the samples showed considerable catalytic activity and excellent reusability in the esterification reaction.
In order to solve the serious leaching problem of supported heteropoly acid catalysts in polar reaction media, 12-molybdophosphoric acid encapsulated in the supercage of Cs + -exchanged Y zeolite was prepared by the “ship in the bottle ” synthesis.The influence of ion -exchange conditions and the synthesis parameters on the encapsulation of PMo12 were investigated. The obtained solid sample was characterized by X-ray diffraction (XRD), 31P magic angle spin nuclear magnetic resonance (MAS NMR) and Fourier Transform Infrared Spectroscopy ), and its catalytic activity in the esterification of acetic acid and n-butanol was tested. ion-exchange time, concentration of aqueous Cs + solution, pH value, and amount of Mo added in the synthesis mixture were revealed to influence the encapsulation very remarkably .Under the optimal conditions, 12-molybdophosphoric acid could be successfully encapsulated in the supercage of CsY zeolite, and the samples show considerable catalytic activity and excellent reusability in the esterification reaction.