F-127作为模板剂合成微孔-介孔SAPO-11分子筛及其在长链烷烃异构化中的应用

F-127 as Template for the Synthesis of Micro-Mesoporous SAPO-11 Zeolite and Its Application in Long-chain Alkane Isomerization

在常规水热法合成SAPO-11的基础上,添加适量F-127作为软模板构造介孔结构,成功合成出了SAPO-11分子筛微介复合体。考察了F-127添加量对分子筛内部的孔道结构的影响,并通过XRD、N_2吸附-脱附曲线、SEM和Py-FTIR等途径对催化剂进行表征。以正十二烷为原料,对负载Pt金属的SAPO-11分子筛进行临氢异构化反应性能评价。结果表明:添加F-127的分子筛内部出现了明显的介孔结构,并且随着F-127添加量的增加,分子筛的介孔孔容呈先增大后减小的趋势;异构化反应结果表明催化剂活性位的数量与分子筛介孔孔容有关;随着温度的升高,异构烷烃转化率升高,异构烃收率下降。催化剂的异构化转化率伴随着F-127的添加量的增加而降低,F-127添加量在一定范围内的增加可使异构烃收率得到提高。在F-127添加量为10%时,异构烃收率达到最高为57.62%。

On the basis of the normal hydrothermal synthesis of SAPO-11,an appropriate amount of F-127 was introduced as the soft template to construct the mesoporous structure. The SAPO-11 molecular sieve with meso-microporous composite structure was successfully synthesized. The effects of F-127 addition on the inner pore structure of molecular sieves were investigated. And the catalysts were characterized by Xray diffraction（ XRD）,N_2 adsorption-desorption curves,scanning electron microscopy（ SEM） and pyridine adsorption infrared spectroscopy（ Py-FTIR）. The results show that along with the increasing addition of F-127,the mesoporous pores of the molecular sieve increase first and then decreaseand the mesoporous structure is produced in the molecular sieve. The isomerization reaction shows that the catalyst activity is related to the mesoporous capacity of the zeolite The conversion rate of alkane rises with the increase of temperature,and the yield of isomer is decreasing. The isomerization conversion rate of the catalyst decreases with the addition of F-127,and the increase of F-127 content in a certain range could lead to the improvement the yield of isomerization. When the addition amount of F-127 is 10%,the yield of isoparaffin reache 57. 62%.