New synthesis of pure orthorhombic Mo-V-A oxide phases, where A=Sb, Bi and Pb, and testing for the oxidation of light alkanes.

A new, microwave-assisted technique has been developed for the synthesis of microporous vanado-molybdate catalysts with an M1-type orthorhombic structure. This method allows various cations such as Sb, Bi and - for the first time - Pb, to be introduced into the hexagonal channels of the structure, without using any expensive structure directing agent. The influence of the aforementioned elements with lone pairs of electrons on the framework structure has been studied, and the crystalline structure of the Pb-containing phase was refined using the Rietveld method and powder diffraction data. The structure determination data are in good agreement with those obtained by different analytical or spectroscopic techniques. The catalytic properties of the catalysts have been determined for the oxidative dehydrogenation of ethane, and for the oxidation of propane into acrylic acid.