The well-ordered polyhydroxyacetato-Cr3+ species intercalated molybdenum trioxide by the reaction of an aqueous solution of Cr(OAC)(3) with a dispersion of layered sodium molybdenum bronze ([Na(H2O)(5)](0.25)MoO3) was prepared, X-ray fluoroscopy (XRF), TGA and near/UV-VIS spectra showed that the intercalates may mainly be trimers and tetramers. The first chromia-pillared molybdenum trioxide with an interlayer distance of 10.9 Angstrom was then obtained after calcined at 350 degreesC in a flow of mixed nitrogen and oxygen (4% O-2, v/v). The obtained porous material has a surface area of 82.4 m(2) g(-1), with ca. 60% of pores having r(p) < 20 Angstrom. XPS result suggested that the chromia pillars existed as Cr2O3 in the interlayer of the material. (C) 2002 Elsevier Science B.V. All tights reserved.