Europium was introduced into K'-exchanged Y-zeolite (K-Y) by impregnation from an ammoniacal solution of the metal.
The catalytic properties of the zeolite were examined by the isomerization of 2,3-dimethylbut-1-ene to 2,3-dimethylbut-2-ene and the Michael reaction of cyclopent-2-enone with dimethyl malonate. The change in the chemical state of tbe Eu was investigated by IR and X-ray adsorption fine structure. IR spectrum showed the presence of Eu amide by evacuating the zeolite around 3.50 K. The amide decomposed successively to Eu imide around 420 K and to Eu nitride around 6 10 K. The Eu L,-edge X-ray absorption near-edge structure (XANES) spectrum showed that the oxidation states of Eu species are Eu' r ( Eu (II) ) and Et?+ (Eu( III) ). The change of IR and XANES spectra, and that of the catalytic activity of Eu introduced into K-Y with the evacuation temperature suggest that the Eu(I1) imide is the catalytically active species for the isomerization of 2,3-dimethylbut-I-ene and the Michael reaction of cyclopent-2-enone with,dimethyl malonate, while the Eu(I1) nitride is active species for the hydrogenation of ethene.