Synthesis of solid materials in molten nitrates

Chemical methods of synthesis of materials play a crucial role in the design and discovery of new materials, and also provide better and less cumbersome methods for preparing known materials. In this paper, the synthesis of inorganic compounds in molten nitrates is discussed. This method can be envisaged in some cases as a soft chemistry route for the preparation of solids. The reaction mechanisms of transition-metal salts and their mixtures in molten nitrates are given. Then, the preparation of dispersed simple oxides, multicomponent systems, layered intercalation hosts and supported catalysts are described. In the field of catalysis, the preparation of solids with controlled textural properties is an important task. Several examples of this molten salt synthesis approach are given with the objective of optimising textural properties for catalytic applications. Management of the reaction can be obtained by modifications of the molten bath by using some dopant such as a nitrite or a carbonate. Examples illustrate the role of this dopant on the crystallisation rate and/or the reaction mechanism. (C) 1998 Elsevier Science S.A. All rights reserved.