Synthesis of SiGeAl-ITQ-13 and SiAl(B)-ITQ-13 and their catalytic performance in the conversion of methanol to hydrocarbons

Abstract

Al-ITQ-13 molecular sieves, viz., SiGeAl-ITQ-13 and SiAl(B)-ITQ-13, were prepared by the direct hydrothermal synthesis and post-synthesis methods and characterized by XRD, 27Al MAS NMR, NH3-TPD, Py-FTIR and SEM; their catalytic performance in the conversion of methanol to hydrocarbons (MTH) was investigated. The results indicated that two Al-ITQ-13 samples have high crystallinity with a slice-like morphology. In comparison with ZSM-5, Al-ITQ-13 as a catalyst in MTH exhibits higher selectivity to propene, higher propene/ethene (P/E) ratio and longer catalytic lifetime. Moreover, as the amount of strong acid sites on SiAl(B)-ITQ-13 is decreased by post-synthesis, SiAl(B)-ITQ-13 exhibits better catalytic performance in MTH, in comparison with SiGeAl-ITQ-13 obtained by direct hydrothermal synthesis.