Dc. Sayle et al., A REFINED MODEL FOR THE ACTIVE-SITE WITHIN THE NO DECOMPOSITION CATALYST, CU-ZSM-5, MICROPOROUS AND MESOPOROUS MATERIALS, 20(4-6), 1998, pp. 259-267
Static atomistic simulation techniques have been employed to identify
a model for the active site configuration and its location within the
NO decomposition catalyst, Cu-ZSM-5. We propose that the active site c
omprises a copper pair, bridged by OH and forming a six membered ring,
specifically, (-O-Cu(II)-OH-Cu(I)-O-Al-), within the zeolite framewor
k. The six-membered ring arises from the strong association of both of
the copper species with a single aluminium in the zeolite framework a
nd consequently the ring is strained, reflected in the low (3.1 Angstr
om) intercopper distance in the cluster. Indeed, this Cu-Cu distance c
ompares well with the experimentally determined value of 3.0. In addit
ion, it :is expected that the strain in the cluster influences the act
ivity of the cluster, which we suggest may be responsible for its uniq
ue activity for NO decomposition. (C) 1998 Elsevier Science B.V.