Investigation of synthesis and hydroisomerization performance of SAPO-11/Beta composite molecular sieve

The SAPO-11/Beta composite molecular sieve was synthesized by the hydrothermal method with Received 7 March 2014 zeolite Beta as the silicon source. The physicochemical properties of SAPO-11, Beta molecular sieve, Accepted 10 April 2014 the composite molecular sieve, and the mechanical mixture of SAPO-11 and Beta molecular sieve Published 20 October 2014 were characterized by X-ray diffraction, N-2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy-energy dispersive spectroscopy, magic-angle spinning nuclear magnetic resonance, and pyridine adsorption infrared spectroscopy. In addition, the catalytic performance of platinum-loaded zeolite samples in the hydroisomerization of n-dodecane was investigated. The results indicate that the properties and catalytic performance of the composite molecular sieve were quite different from those of the pure zeolites and the mechanical mixture. Compared with the mechanical mixture, the combination of SAPO-11 and Beta by chemical bonds was more tightly bound in the composite molecular sieve with a core-shell structure. The acidity and pore structure of the composite were favorable for catalytic performance in the hydroisomerization of n-dodecane. The composite catalyst was superior to the other catalysts, especially in the yield of multibranched isomers. (C ) 2014, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.