CAJ | 학술논문

研究了氟介质条件下,合成参数对前驱体黏度和无铝Beta分子筛晶化过程的影响. X射线衍射结果表明,高水硅比可降低前驱体的黏度,但抑制分子筛的晶化.当合成体系中加入成核促进剂(二氧化锗)和晶化促进剂(高氯酸根或磷酸根)后,即使水硅摩尔比高达20~30,在150℃水热合成4 d,仍可获得高结晶性、微米级球形或多面体形无铝Beta分子筛.热重和能谱分析结果表明,极少量高氯酸根和磷酸根可进入分子筛孔道,并影响模板剂四乙基铵根离子的热分解过程.氮气吸附-脱附、扫描电子显微镜、透射电子显微镜和选区电子衍射分析结果表明,所得无铝Beta分子筛具有多级孔结构,介孔尺寸在3.4~3.8 nm之间,由纳米晶体或纳米棒堆积而成.
연구료불개질조건하,합성삼수대전구체점도화무려Beta분자사정화과정적영향. X사선연사결과표명,고수규비가강저전구체적점도,단억제분자사적정화.당합성체계중가입성핵촉진제(이양화타)화정화촉진제(고록산근혹린산근)후,즉사수규마이비고체20~30,재150℃수열합성4 d,잉가획득고결정성、미미급구형혹다면체형무려Beta분자사.열중화능보분석결과표명,겁소량고록산근화린산근가진입분자사공도,병영향모판제사을기안근리자적열분해과정.담기흡부-탈부、소묘전자현미경、투사전자현미경화선구전자연사분석결과표명,소득무려Beta분자사구유다급공결구,개공척촌재3.4~3.8 nm지간,유납미정체혹납미봉퇴적이성.
The influence of various parameters upon the physical state of precursor and crystallization of alu-minum-free Beta zeolite were investigated in fluoride media. X-Ray diffraction(XRD) analysis showed that H2 O/SiO2 molar ratio in the precursor played an important role in the viscosity of precursor and the crystallization of aluminum-free Beta zeolite. High H2O/SiO2 molar ratio(>10) was benefited to the precur-sor's viscosity but inhibited the crystallization process of aluminum-free Beta zeolite. While, high crystalline aluminum-free Beta zeolite with polyhedron or sphere morphology in micrometer scale could be obtained in the presence of nucleation promoter( GeO2 ) and crystallization promoter such as ClO-4 and PO3-4 at 150 ℃ for 4 d, even though H2 O/SiO2 molar ratio was high to 20-30. The analysis of thermogravimetry and energy dispersive spectrometry proved that small amount of ClO-4 and PO3-4 maybe incorporated into the channel of Beta zeolite and influenced the thermal decomposition process of template ( tetraethyl ammonium cation ) . Further charac-terization for the morphology, crystalline and pore structure of the resultant aluminu-free Beta zeolite were carried out by environmental scanning electron microscope(SEM), transmission electron microscope(TEM), selected-area electron diffraction ( SAED ) and nitrogen adsorption-desorption isotherm. The results indicate that the obtained aluminum-free Beta zeolite is hierarchical structure, which constructed by nanoparticles or nanosheets. The mesoporous pore size is in the range of 3. 4-3. 8 nm.