Syhthesis And Characterization Of Nano-sized NaY Zeolite

Nano-sized NaY zeolite is a kind of porous materials with uniform pore size. Compared with traditional μ-NaY zeolite, Nano-sized NaY zeolite has more excellent characteristics, such as a short and neat hole, higher specific surface area and active sites on external surface. In current synthetic of Nano-sized NaY zeolite was mostly have adding additive such as the template agent, surface active agent in order to prevent the grain grew up in the process, the addition of these additives not only increase the cost of the preparation of nanometer NaY zeolite, but also have a complicated operation process.In this article, Nano-sized NaY zeolite were hydrothermally synthesized, without adding any organic additives.The micro-structure and crystallization process of the samples were characterized using XRD,SEM,TEM,FR-IR and BET.Experimental conditions were studied on its crystal structure, crystallinity, and the influence of the grain size, etc. The main research contents and conclusions were as follows:1) The experimental conditions was studied for its crystal structure, crystallinity and the influence of the grain size, etc. Optimum synthesis of Nano-sized NaY zeolite are obtained: NaY zeolite crystallization temperature is100℃, crystallization time is8h, silicon aluminum gel pH value of15,20%agents to join.2) Through the three-step aging not only avoids the system quadratic aggregation of high surface energy of the crystal nucleus, and in the process of crystallization, to avoid the multiple root and silicate aluminum acid radical ion in solution directly on the nucleus rapidly into crystal grain size larger NaY zeolite. The particles sizes are in the range of40～80nm.3) Different mixing equipment is studied on the properties of silica alumina gel micromixing effect. RSR stirring only need15mins to make the silicon aluminum gel viscosity reached a maximum of550mPa·s, after the crystallization product granularity in50～80nm; And magnetic mixer mixing11h, its maximum value is130mP·a-s. viscosity, crystallization product granularity after in50-150nm. 4) The study found that the absorption frequency of the nano-sized NaY zeolite’s infrared spectrum is O～10cm-1higher than conventional NaY, have a blue shift phenomenon.5) By the nitrogen adsorption/stripping analysis:Nano-sized NaY zeolite sieve adsorption equilibrium isothermal curves of type Ⅰ, belong to the microporous material, and the pores are mainly distributed in around0.7nm, hole size around0.41cm3/g; The grain size at around1OOnm, the specific surface area is about629m2/g, when grain size at40-80nm, the specific surface area increased to around709m2/g.