二次生长法合成多级孔道FAU/氧化铝复合物

以整体型大孔-介孔氧化铝为载体，使用浸涂法负载NaY晶种并二次生长合成大孔-介孔-微孔FAU/氧化铝复合物，考察载体晶型及晶种胶的辅助对合成沸石复合物的影响；采用XRD、 SEM、氮气吸附-脱附、DTA/TG对合成样品进行表征。结果表明：沸石在整体材料上的覆盖度由载体的物化性质、晶种悬浊液或二次晶化液的化学组成共同决定；γ-Al2O3载体经过含晶种胶的沸石悬浊液负载晶种，二次晶化后形成载体骨架部分转化为沸石且保持载体微观形貌的结构；α-Al2O3载体沸石的覆盖度因二次晶化液中晶种胶的辅助作用而明显改善。

SYNTHESIS OF HIERARCHICALLY POROUS ZEOLITE FAU/ALUMINA COMPOSITES BY SECONDARY GROWTH ON SEEDED ALUMINA SUBSTRATES

The trimodal porous structured hierarchical FAU/alumina composite (macro-pores/meso-pores/micro-pores) were hydrothermally synthesized using macro-mesoporous alumina monoliths as substrates by seeding and secondary growth method. The influences of supports with different physicochemical features and the seed gel assistant on the properties of the resultant composites were studied. The zeolite seed and composites were characterized by XRD, SEM, nitrogen adsorption-desorption isotherms and DTA/TG. The results show that the coverage of zeolite on monoliths was determined by both of the physicochemical features of the substrates and the chemical compositions of the seed suspension or secondary crystallization solution. After being seeded, the substrate of γ-Al2O3 was partially transformed into zeolite structure with the retainment of the original substrate morphology. The zeolite coverage on α-Al2O3 support is improved significantly by the assistant of seed gel.