Synthesis and Xylene Isomerization Properties of Hierarchical Eu-1 Zeolite

Abstract

A series of hierarchical EU-1 molecular sieves with different mesoporous/microporous ratios were prepared by adding water-rich gelatinized starch into the synthesis system of EU-1 molecular sieves. The effects of the amount of gelatinized starch on the crystallization process and the physicochemical properties of the final product were investigated. The synthesized EU-1 molecular sieve was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2-adsorption desorption and ammonia temperature programmed desorption (NH3-TPD). The catalytic performance of the synthesized EU-1 molecular sieve in the Xylene Isomerization reaction was studied. The results show that the introduction of gelatinized starch is beneficial to the formation of intergranular mesopores, and the regular changes of mesoporous/micropore volume ratio can be regulated by the amount of gelatinized starch. The amount of gelatinized starch gradually increases from 0% to 6%, and the mesoporous/micropore volume ratio of EU-1 molecular sieve gradually increases from 1.55 to 4.44.The equilibrium concentration of p-xylene and the yield of C8 increased with the increase of the mesoporous/microporous volume ratio of EU-1 molecular sieve in the Xylene Isomerization reaction. The equilibrium concentration of p-xylene gradually increased from 23.35% to 23.85%, and the yield of C8 gradually increased from 95.76% to 97.15%.