Modification of Mesoporous CaZr4(PO4)6 and its Acid Catalytic Performance

Abstract

A series of new type acid catalyst samples based on mesoporous CaZr4(PO4)6(CZP) belonging to NZP family synthesized by sol-gel method was obtained by Al, La, B incorporation in CZP or by heteropoly acid H3PW12O7•xH2O(HPW) loading on CZP, and their acid catalytic activity and selectivity were investigated by using α-pinene isomerization as a probe reaction. The phase, pore structure and surface acidity of the catalyst samples were characterized by X-ray diffraction (XRD), N2 sorption and NH3 temperature programmed desorption (NH3-TPD) respectively. The results showed that the surface acidity of CZP modified by elements incorporation and HPW loading was improved in a different extent. The conversion of α-pinene at 150 °C reached to 41 % over the catalyst sample noted as Al-CZP-0.15 in which the mole ratio of Al to Zr was 0.15. Under the same reaction conditions, the conversion of α-pinene was above 95 % over the CZP supported with 20-30wt. %HPW.