Zeolite acid strength and reaction mechanisms in catalysist
Zeolite acid strength and reaction mechanisms in catalysist
复制标题
DOI：
10.1039/b206483a
复制
发表时间：
2002-11-15
影响因子：
3.3
通讯作者：
Haw, JF
中科院分区：
文献类型：
--
作者：
Haw, JF
最具有实际意义的非均相催化剂是酸性沸石，它们无法使用传统的特高压表面科学方法进行研究。就在 1994 年，人们几乎一致认为沸石是超强酸，催化中许多最重要的反应机制都是基于简单的碳正离子和其他外来的高能中间物质。本文回顾了一系列研究，其中许多研究使用固态核磁共振，这些研究导致了沸石酸度的重新分类，并为了解这些令人着迷的固体中的碳离子稳定性提供了理论基础。基于对沸石酸强度和作为沸石中合理中间体的碳正离子类型的更好理解，有可能阐明具有挑战性的机械问题的许多特征：甲醇到碳氢化合物的催化。
The heterogeneous catalysts of greatest practical importance are acidic zeolites, and these cannot be studied using the traditional methods of UHV surface science. As recently as 1994 there was near universal agreement that zeolites were superacids, and that many of the most important reaction mechanisms in catalysis were based upon simple carbenium ions and other exotic high-energy intermediate species. This Paper reviews a series of investigations, many of them using solid-state NMR, that led to the reclassification of zeolite acidity and a theoretical basis for understanding carbenium ion stability in these fascinating solids. Building on this better understanding of zeolite acid strength and the types of carbenium ions that are reasonable intermediates in zeolites, it was possible to elucidate many of the features of a challenging mechanistic problem: methanol to hydrocarbon catalysis.