X-Ray Absorption Studies of The Interaction Between Pd and Co-In Bimetal Exchanged Zeolitey

摘要: The ion-exchange and reduction process in zeolite Y exchanged with [Co(NH 3 ) 6 ] 3+ and/or [Pd(NH 4 2+ has been studied. Extended X-Ray Absorption Fine Structure Spectroscopy (EXAFS) was used to monitor the local environment of cobalt palladium atoms at various stages sample treatment. Upon dehydration, Co is reduced migrates into cation positions. Treatment hydrogen 625 K does not change oxidation state. Intrazeolite Pd coordinated six-membered rings framework. palladium(II) phase can partially be 0 room temperature, while 100% achieved 425 K. reduction, small ensembles are formed (2-4 atoms) which stabilized sodalite units through weak interaction matrix. Reduction results cluster formation a particle size ≥ 10 A. presence Co(II) Pd-exchanged zeolites increases degree H 2 -reduction temperature facilitates agglomeration phase. At higher temperatures, CoPdY against further aggregation. It concluded that distribution early critical for sinter stability.