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采用 Py- TPD、XRD、IR等主要实验方法 ,研究了 Naβ沸石原粉经 NH+ 4 交换后脱胺对β沸石表面酸性和结构的影响以及焙烧温度对 NH+ 4 - β沸石骨架脱铝的影响。结果表明 ,高温脱胺 ,β沸石有明显的骨架脱铝过程发生 ,而迁移到 β沸石表面酸性位上 ,使表面较体相富铝 ,脱铝导致其表面酸性的减弱 ;β沸石随焙烧脱胺温度的升高 ,其表面酸量逐渐减少 ,酸强度也逐渐降低 ,L酸主要来源于骨架三配位铝 ,它比非骨架铝酸强度高 ;随脱胺温度的提高 ,β沸石晶相结构和骨架结构破坏程度均加深 ,NH+ 4 在脱胺过程中对 β沸石的结晶度影响不大 ,而交换后的 NH+ 4 较 Na+ 更不利于抑制骨架脱铝
The effects of deamination on the surface acidity and structure of zeolite beta and the calcination temperature on the dealumination of NH + 4 - zeolite zeolite were investigated by Py-TPD, XRD and IR. The results show that zeolite beta has obvious skeleton dealumination at high temperature, but migrates to the acid site of zeolite beta, which makes the surface more aluminum-rich, which leads to the decrease of acidity on the surface of beta zeolite. When the temperature of amine increased, the surface acidity gradually decreased and the acid strength decreased gradually. L acid was mainly derived from the framework tri-coordinated aluminum, which was higher than that of the non-framework aluminic acid. With the increase of deamination temperature, The degree of destruction of the structure and the skeleton structure are deepened, NH +4 has little effect on the crystallinity of zeolite beta during the deamination, and the exchanged NH + 4 is more unfavorable for inhibiting the dealumination of the framework