Studies on the State of Copper and the Formation of its Oxidic and Metallic Phases in Zeolite Cunay
Review articleOpen access
R. Piffer - No affiliation found
1991/01/01 Full-length article DOI: 10.1016/S0167-2991(08)61577-3
AbstractThe oxidation state of Cu ions in zeolite Y depends on the pretreatment procedure. After activation for more than 8 hours at 675 K phases similar to CuO occur. Admitting hydrogen at 575 K, a reduction to Cu(I) but not to Cu(O) metallic clusters is observed. Probably a reaction with extraframework oxygen takes place. However, a reduction to rather small metallic copper clusters is observed after co-addition of water vapour and hydrogen. This demonstrates the important role of strong ligands like water in the reduction mechanism, enabling a controlled formation of copper clusters.
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