Platinum has been incorporated into the layered vanadyl hydrogen phosphate VOHPO4.0.5H(2)O in different ways depending upon the medium of its preparation. The phase obtained by the introduction of platinum during the synthesis of VOHPO4.0.5H(2)O in aqueous medium is a new crystalline phase with mixed-valent vanadium containing Pt2+ species. This phase forms a novel hydrogen insertion compound involving hydrogen spillover from the incorporated platinum onto the VPO matrix. On the other hand, the incorporation of platinum during the synthesis of the hemihydrate in organic medium gives rise to a phase containing both metallic platinum and an amorphous Pt2+ containing VPO phase. Both these platinum incorporated phases have been found to be active catalysts for reduction and oxidation reactions such as the hydrogenation of nitrobenzene and the oxidation of tetrahydrofuran with the activity varying quite markedly with the mode of incorporation. (C) 2002 Elsevier Science B.V. All rights reserved.