多级孔SAPO-5分子筛的合成及其在柴油加氢精制催化剂中的应用

以十六烷基三甲氧基有机硅氯化铵（TPHAC）为介孔模板剂，通过一步水热法合成具有微孔-介孔结构的多级孔SAPO-5分子筛（HI-SAPO-5）。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、N2-吸附/脱附、X射线荧光光谱（XRF）、吡啶吸附红外光谱等表征方法研究HI-SAPO-5分子筛的物化性质。结果表明：在常规SAPO-5分子筛（N-SAPO-5）合成体系中引入TPHAC能够合成出纯相的HI-SAPO-5；与N-SAPO-5相比，HI-SAPO-5具有更高的外比表面积与介孔孔体积以及适宜的酸量与酸强度。将HI-SAPO-5引入γ-Al2O3载体中，制备成柴油加氢精制催化剂。焦化柴油加氢评价结果表明，引入HI-SAPO-5的催化剂表现出优异的加氢脱硫、加氢脱氮与芳烃加氢饱和性能，产物中的硫质量分数为8 μg/g，双环以上芳烃质量分数为1.1 %。

SYNTHESIS OF SAPO-5 MOLECULAR SIEVE HAVING HIERARCHICAL PORE STRUCTURE AND ITS APPLICATION IN HYDROREFINING CATALYST FOR DIESEL FUEL

SAPO-5 molecular sieve having hierarchical pore structure (HI-SAPO-5) was synthesized by one-step hydrothermal crystallization method using 3-(trimethoxysilyl) propyl hexadecyldimethyl ammonium chloride (TPHAC) as mesopore directing surfactant. Samples were analyzed by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption and pyridine-adsorbed infrared (Py-IR). Characterization results showed that pure HI-SAPO-5 molecular sieve was obtained by introducing THPAC into the synthesis system of normal SAPO-5 molecular sieve (N-SAPO-5). Compared with N-SAPO-5 molecular sieve, HI-SAPO-5 molecular sieve possessed much higher external specific surface area, larger mesopore volume, more suitable acid amount and acid strength. As a result, these advantages were in favor of the mass transfer and conversion of bulky sulfur compounds and polyaromatic hydrocarbons. Evaluation results showed that when coker gas oil was hydrotreated over catalyst containing HI-SAPO-5 molecular sieve, improved hydrodesulfurization, hydrodenitrogenation and hydrodearomatization performance were exhibited. The mass fractions of sulfur and above two-ring aromatic hydrocarbons in the treated oil were 8 μg/g and 1.1 %, respectively.