Abstract: A method of preparing acrolein from glycerol or glycerine is disclosed. The method includes dehydrating glycerol or glycerine in the presence of a catalyst consisting of at least (a) a mixed oxide of zirconium and at least one metal, said metal being selected from niobium, tantalum and vanadium, or (b) a zirconium oxide and at least one metal oxide, the metal being selected from niobium, tantalum and vanadium, or (c) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, or (d) a titanium oxide and a mixed oxide of zirconium and at least one metal, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon.

Abstract: The invention relates to a method for preparing acrolein from glycerol or glycerine, comprising dehydrating glycerol or glycerine in the presence of a catalyst consisting of at least a) a mixed oxide of zirconium and at least one metal, said metal being selected from niobium, tantalum and vanadium, b) a zirconium oxide and at least one metal oxide, the metal being selected from niobium, tantalum and vanadium, c) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, d) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and titanium, e) a titanium oxide and a mixed oxide of zirconium and at least one metal, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, f) a titanium oxide and a mixed oxide or zirconium and at least on

Abstract: The invention concerns solids comprising a single tungsten oxide layer on a zirconia support and/or titanium dioxide support, characterized in that the tungsten exhibits tetrahedral co-ordination, before and after calcining. The invention also concerns the method for preparing the solids, and their uses as acid catalysis reactions catalyst.

Abstract: The invention concerns solids comprising a single tungsten oxide layer on a zirconia support and/or titanium dioxide support, characterized in that the tungsten exhibits tetrahedral co-ordination, before and after calcining. The invention also concerns the method for preparing the solids, and their uses as acid catalysis reactions catalyst.