Correlating Synthetic Methods, Morphology, Atomic-Level Structure, and Catalytic Activity of Sn-β Catalysts

摘要: Sn-β zeolites prepared using different recipes feature very catalytic activities for aqueous phase glucose isomerization, suggesting the presence of active sites. A systematic study morphology and atomic-level structure materials DNP NMR spectroscopy in combination with first-principles calculations allows discrimination between potential sites leads to a proposal specific structural features that are important high activity. The results indicate showing highest activity possess highly hydrophobic, defect-free zeolite framework. Those show so-called closed associated partially hydrolyzed Sn(IV) T6 T5/T7 lattice positions. On other hand, postsynthetically synthesized samples two steps via dealumination subsequent solid-state ion exchange from Al-β significantly lower activity, which is hydrophilic framework and/or accessibility differ...