摘要
The coordination structures of Ni<sup>2+</sup> in Y zeolite have been characterized by laboratory EXAFS technique. Dehydration at 773 K resulted in a Ni-O bond of 2.11 with a coordination number （c.n.） of 3. The following reduction in 40×10<sup>3</sup> Pa H<sub>2</sub> at 573 K for 40 min produced two kinds of coordination structures. One was the Ni-Ni bond of 2.48 with c. n. of 0.8 which corresponded to the formation of fine metal cluster, while the
