H-SSZ-13分子筛催化乙醇脱水制乙烯反应的原位固体核磁共振研究

本文采用原位连续流动条件和间歇条件下的固体核磁共振技术，以及二维¹³C-¹³C基于偶极耦合的结合R2（COmbined R2 Driven，CORD）自旋扩散序列的核磁共振实验捕获了H-SSZ-13分子筛催化乙醇脱水过程中多种中间物种，并揭示了各种中间物种的动态演变过程.结果发现H-SSZ-13分子筛催化乙醇脱水过程中，存在两种不同吸附构型的乙醇、活化态的乙醚、乙氧基以及三乙基氧鎓离子，并首次通过原位固体核磁共振技术观测到乙烯的生成.这些结果加深了相关研究者对乙醇脱水反应的认识.

Investigation of the Ethanol Dehydration to Ethene Reaction on H-SSZ-13 Molecular Sieve by in situ Solid-state NMR Spectroscopy

In situ solid-state nuclear magnetic resonance (ssNMR) techniques under continuous flow and batch-like conditions as well as 2D ¹³C-¹³C dipolar-based COmbined R2 Driven (CORD) spin diffusion NMR experiments were utilized to investigate the dehydration process of ethanol on molecular sieve H-SSZ-13. Kinds of intermediate species including ethanol with different adsorption orientation, diethyl ether under activated state, the surface ethoxy, triethyloxonium ion and even ethene were captured directly, and the evolution process of these intermediate species was also revealed in this paper. Moreover, it can be emphasized that the ethene species were observed in situ by ssNMR for the first time. These results enriched the fundamental research of ethanol dehydration reaction.