A novel synthesis route for high surface area spinels using ion exchanged zeolites as precursors

Transition metal spinels, with particle sizes in the nanometer range crysta llize from transition metal exchanged zeolites during calcination. The spin els are covered by an amorphous silica which prohibits access to the surfac e of the spinel particles. Dissolution of the silica in alkaline solution l eads to spinels with high surface areas, caused by small particles. The com position of the zeolites as well as the calcination time and temperature ar e important parameters which take influence on the properties of the obtain ed spinels. Correct adjustment of these parameters enables control of the s pinel particle sizes. The obtained transition metal spinels, having high su rface areas up to 200 m(2)/g, may find use as catalysts or catalyst support s. (C) 2001 Elsevier Science B.V. All rights reserved.