Hierarchical Fe-, Cu- and Co-Beta zeolites obtained by mesotemplate-free method. Part I: Synthesis and catalytic activity in N2O decomposition

Two series of BEA zeolites (Beta and Beta/mesa) have been prepared. A first series of the samples was obtained by a conventional aging of parent zeolite gel, while the second series (Beta/meso) was prepared by mesotemplate-free method. In this method Beta nanoparticles are aggregated under acidic conditions with the formation of micro-mesoporous material. Both series (Beta and Beta/mesa) were doped with Fe, Cu and Co by ion-exchange method and tested as catalysts of N2O decomposition. The Cu-Beta catalyst was found to be the most active in the process of N2O decomposition conducted in inert gas atmosphere. However, in the process performed under conditions similar to those prevailing in waste gases emitted from nitric acid plants (one of the main sources of N2O emission) higher reaction rate was found for the Cu-Beta/meso catalyst. (C) 2014 Elsevier Inc. All rights reserved.