New perspectives on basic zeolites as catalysts and catalyst supports [Review]

摘要

Zeolites are aluminosilicate molecular sieves that have great potential as basic catalysts and catalyst supports. In particular, this paper discusses recent work and future directions with zeolite X containing exchanged alkali metal cations, occluded alkali metal oxides, and occluded alkali metals. Probe reactions such as alkylation of toluene with methanol, cyclo-addition of carbon dioxide to ethylene oxide, isomerization of I-butene, and alkylation of toluene with ethylene are catalyzed by the basic X zeolites, depending on the preparation method. Basic zeolites are also excellent supports for nanometer-sized Ru metal clusters used to catalyze the ammonia synthesis reaction. In that case, occluded barium oxide effectively promotes the reaction on Ru-loaded Ba-exchanged zeolite X. These examples illustrate important principles that can be used to guide future design of shape-selective base catalysts. (C) 2003 Elsevier Science (USA). All rights reserved. [References: 104]