On the oxygen effect in nitric oxide reduction by methane over Co/ZSM-5

The catalytic reduction of NO by CH4 over Co/ZSM-5 zeolite is studied by me ans of transient in situ DRIFT, SSITK and TAP analyses. Co ions located at the interface of Co clusters and zeolite are found to react with NO in the presence of oxygen to form anchored NO2delta+ species stabilized under reac tion conditions. These species form the main active sites for activating me thane molecule. Two ways of CO2 formation from the same intermediate includ ing fragments of both NO2 and partially dehydrogenated CH4 molecule are pro posed in the mechanistic scheme of the reaction. (C) 1999 Elsevier Science Ltd. All rights reserved.