Catalytic properties of new ternary Nb-Sb-V oxide – A comparative study with mechanical mixture of single oxides and binary systems

The study presents a comparative analysis of catalytic properties of new Nb2SbVO10 ternary oxide against those of a mechanical mixture of single oxides and a mixture of single with binary oxide, all of the same chemical composition. Moreover, the material without antimony (Nb9VO25) was tested. Acid–base and redox properties were studied in the following test reactions: 2-propanol decomposition, acetonylacetone (AcOAc) cyclisation and methanol oxidation. The properties of ternary oxide and the mechanical mixture of single oxides are not significantly different. The main difference is in the generation of more active Lewis acid–base pairs in ternary oxide, which is demonstrated by the higher production of ether in the intermolecular dehydration of 2-propanol. Acidic/basic and redox properties of the oxide catalysts containing Nb, Sb, V, O (atomic ratio: 2:1:1:10) strongly depend on the presence of binary oxide, which significantly enhances the basicity of the catalysts. The highest basicity was found for pure binary oxide Nb9VO25 but this catalyst without Sb exhibits much lower activity in the transformation of both alcohols.

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► Binary metal oxides are responsible for basicity of mixed oxides.
► Acid and redox properties of ternary oxide are similar to those of mixed single oxides.
► Ternary Nb2SbVO10 exhibits Lewis acid–base pairs of higher activity than mixed single oxides.
► The presence of antimony enhances activity of mixed oxides in reactions studied.