六氟硅酸铵后处理对H-ZSM-5分子筛酸性影响的固体NMR研究  

The Effects of Ammonium Hexafluorosilicate Post-Treatment on the Acidity of H-ZSM-5 Zeolite Studied by Solid-State NMR Spectroscopy

作　　者：王永祥 王强 徐君 夏清华 邓风 WANG Yong-xiang;WANG Qiang;XU Jun;XIA Qing-hua;DENG Feng(Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules,Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry,Hubei University,Wuhan 430062,China;State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Innovation Academy for Precision,National Centre for Magnetic Resonance in Wuhan,Wuhan 430071,China)

机构地区：[1]湖北大学,有机化工新材料湖北省协同创新中心&有机功能分子合成与应用教育部重点实验室,湖北武汉430062 [2]中国科学院精密测量科学与技术创新研究院,波谱与原子分子物理国家重点实验室,武汉磁共振中心,湖北武汉430071

出　　处：《波谱学杂志》2021年第4期514-522,共9页Chinese Journal of Magnetic Resonance

基　　金：国家自然科学基金资助项目(21733013和91745111).

摘　　要：本文利用固体核磁共振(NMR)实验对六氟硅酸铵(AHFS)溶液洗涤前后H-ZSM-5分子筛上铝物种变化引起的酸性改变进行了研究.结果显示经AHFS洗涤处理后,分子筛上构成Brønsted酸的骨架四配位铝物种会部分减少;具有Lewis酸性的骨架三配位铝量在经AHFS脱铝处理后少量降低;同时AHFS温和脱铝的方式主要会引起分子筛上另一类具有Lewis酸性且含Al-OH的铝物种大量减少,从而导致处理后分子筛整体酸性的显著改变.In this study,solid-state nuclear magnetic resonance(NMR)spectroscopy was used to probe the changes of acidity of H-ZSM-5 zeolite caused by ammonium hexafluorosilicate(AHFS)washing-related changes of aluminium species.It was observed that the four-coordinate framework aluminum species with Brønsted acidity were partially reduced,while the tri-coordinated framework aluminum with Lewis acidity was slightly decreased after the AHFS treatment.However,AHFS washing was also found to induce mild dealumination and a significant reduction of aluminum species with Lewis acidity containing Al-OH group on zeolites,thus resulting in a remarkable change in the overall acidity of the zeolites.

关 键 词：六氟硅酸铵(AHFS) 三甲基氧膦(TMPO)探针分子 酸性 固体核磁共振 

分 类 号：O482.53[理学—固体物理]