ISSN:
1572-879X
Schlagwort(e):
Cobalt/zeolite
;
Na acetate assisted Co reduction
;
high dispersion of transition metals
;
zeolite supported transition metals
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract A method has been devised to prepare reduced Co clusters in zeolite Y. Sodium acetate is impregnated after exchanging Co2+ ions into the zeolite. During calcination the acetate is partially or completely oxidized to sodium oxide. This not only stabilizes Co2+ ions in supercages, impeding their migration to smaller cages, but it also neutralizes the protons that are formed during the reduction of the Co2+ ions with H2. As a result, the temperature of effective reduction is lowered by up to 350 °C, depending on the calcination program. In unmodified zeolites, Co reduction requires a temperature above 750 °C, which inevitably induces partial destruction of the zeolite lattice; this novel method permits complete reduction of Co without damaging the zeolite lattice. It is predicted that this novel method should be applicable to other zeolite encaged metals of low reducibility such as Ni.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00769500
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