Synthesis of Fe substituted aluminophosphate FeAPO-5 zeolite with mesoporosity in compressed CO2 for the improved catalytic activity

In this work, we demonstrate a novel route for synthesis of Fe substituted aluminophosphate FeAPO-5 in compressed CO2. The synthesized FeAPO-5 contains mesoporosity without use of additional mesotemplate. The mesoporosity was formed by CO2-in-water emulsions during the crystallization process. Moreover, the crystallization time of FeAPO-5 nanoparticles was shortened in the presence of compressed CO2 compared with the normal FeAPO-5 synthesized without CO2. Because of the existence of mesopores favoring the diffusions of the reactants and products, FeAPO-5 catalyst displayed higher activity for styrene epoxidation than normal FeAPO-5. The compressed CO2 route opens a simple, green and economic synthesis route for synthesis of hierarchical zeolites, which are of great importance to industrial applications. (C) 2013 Elsevier B.V. All rights reserved.