The first chromia-pillared layered molybdenum trioxide was synthesized by the ion-exchange reaction of the layered hydrated sodium molybdenum oxide bronze with chromium (Ⅲ) acetate [Cr(OAc)~3] aqueous solution and subsequent calcination of the resultant solid product at 350℃. The obtained chromia-pillared molybdenum oxides were porous layered materials with high specific surface area. The products were characterized by XRD, TEM, DTA and BET. The influences of the different calcination atmospheres at 350℃ on the interlayer distance, the specific surface area and the pore size of the resulting product are also discussed. It was found that the obtained materials possess the same interlayer distance (d=1.092nm) and different BET specific surface areas under defferent calcination conditions. Among them, the product calcined in a flow of V(O~2)/V (N~2+O~2)=4% had the greatest specific surface area of 82.4m^2·g^-^1 and an average pore diameter of 6.42nm.

Key words: CHROMIUM OXIDE, MOLYBDENUM OXIDE, X-RAY DIFFRACTION ANALYSIS, TRANSMISSION ELECTRON MICROSCOPY, ION EXCHANGING