Copper clusters in mordenite. A direct structural comparison with the NO decomposition catalyst Cu-ZSM-5

Using computer simulation techniques we have identified the configuration and location of copper clusters in Cu-mordenite. Fundamental differences are found between these clusters and those generated in an analogous modelling study of Cu-ZSM-5, which, considering the structural similarity between these two zeolitic materials, suggests that the host lattice exerts a critical influence on the configurations of the copper species that form within its internal pore structure. We observe a much reduced occurrence of CuII-OH-CuI species, which we suggested previously represents a useful model for the active site in Cu-ZSM-5 and which may therefore provide a structural explanation for the much reduced activity of Cu-mordenite compared with Cu-ZSM-5 for NO decomposition.