利用聚合物的性质制备X型分子筛

Synthesis of X-type Molecular Sieves via Using Property of Ploymer

以聚合物甲基纤维素作空间位阻剂合成了X型分子筛。对合成的样品进行了XRD、BET与SEM等表征。结果表明,随甲基纤维素加入量的增加,合成样品的BET、孔体积与颗粒尺寸减小,而且BET与孔体积减小幅度增大,外比表面先增大后减小,但加入甲基纤维素量过多会导致合成样品的相对结晶度下降。与常规水热法相比,加入了空间位阻剂甲基纤维素成功地限制了颗粒的生长,合成样品的相对结晶度与外比表面增大,BET、孔体积与颗粒尺寸都减小,而且15g凝胶加2.5g甲基纤维素合成的样品最好,其相对结晶度为110%,外比表面为24.3cm2/g,BET为600.9cm2/g,孔体积为0.255cm3/g,平均颗粒尺寸为1.5μm,是常规水热法合成样品平均粒径的1/4。

X-type molecular sieves are synthesized by using polymer methylcellulose as a space-confined additive. The as-synthesized products are characterized by XRD, BET and SEM, respectively. The results show the BET, micropore volume and particle size of as-synthesized samples decrease, and the reducing amplitude of BET and micro- pore volume increases, the external surface area of samples increases first and then decreases, when the content of methylcellulose increases. However, the excessive content of methylcellulose results in the decrease of relative crystal- linity of samples. Compared with the conventional hydrothermal method, adding the space-confined additive（methyl- cellulose） limits successfully the growth of particles, the relative crystallinity and external surface area of the as-syn- thesized samples increase and the BET, micropore volume and particle size decrease. The as-synthesized sample from adding 2. 5g methylcellulose into 15g colloidal is best. Its relative crystallinity is 110%, external surface area is 24. 3cm2/g, BET is 600. 9cm2/g, micropore volume is 0. 255cm3/g, and average particle size is 1.5μm, which is 1/4 average particle size of sample synthesized by the conventional hydrothermal method.