^(27)Al和^(29)Si MAS-NMR对Mo/HZSM-5催化剂的研究  

Study Mo/HZSM-5 Catalysts by NMR

作　　者：刘薇[1] 徐奕德[1] 李丽云[2] 胡红兵[2] 

机构地区：[1]中国科学院大连化学物理研究所催化国家重点实验室,大连116023 [2]中国科学院武汉物理研究所波谱与原子分子国家重点实验室,武汉430071

出　　处：《物理化学学报》1997年第8期693-699,共7页Acta Physico-Chimica Sinica

摘　　要：使用29Si和27Al固体高分辨核磁技术对甲烷无氧芳构化催化剂Mo／HZSM－5分子筛进行了研究，发现HZSM－5分子筛本体中仅含有少量非骨架Al，Mo物种与分子筛骨架Al及骨架外Al的相互作用随Mo担载量以及焙烧温度的升高而增加，在高温焙烧下，Mo物种会使分子筛骨架严重脱铝，并且生成Al2（MoO4）3新相，最终导致分子筛骨架塌陷，催化性能下降.By using high-resolution solid state Nuclear Magnetic Resonance spectrometer with 27Al and 29Si probes, the interaction between Mo species and HZSM-5 of Mo/HZSM-5 catalysts has been studied. The results show that there is a strong interaction between Mo species and HZSM-5zeolite. The framework aluminum in the zeolite can be easily extracted by the introduction of Mo species. The extract ability of framework aluminum by Mo species increases with increasing Mo loading and the calcination temperature. The extraction process leads to the formation of nonframework Al at first and then a new crystalline phase of Al2(MoO4)3. The catalyst, therefore,lost its catalytic activity for methane dehydrogenation and aromatization in the absence of oxygen.The MAS NMR results give us an evidence that Al2(MoO4)3 crystallites are much less active for the reaction.

关 键 词：钼催化剂 铝27 硅29 HZSM-5 甲烷 芳构化 

分 类 号：O643.36[理学—物理化学] O623.11[理学—化学]