| abstract |
The present invention is related to a method for preparing an X-ray amorphous or weakly crystalline metal oxide fluoride of a composition represented by the formula M a+ O b F c comprising the steps ofn a) providing a precursor, whereby the precursor is a fluorinated metal compound having a composition which is represented by the formula M a+ F (a-d) B d L x ; b) converting the precursor into an metal oxide/hydroxide fluoride; and c) calcinating the metal oxide/hydroxide fluoride having the formula M a+ O e H f F c to generate the X-ray amorphous or weakly crystalline metal oxide fluoride of the formula M a+ O b F c , nwhereby M is selected from the group comprising metals of the first, second, third and fourth main group and any subgroup of the periodic table; B is a group or an anion which is selected from the group comprising alkoxide, enolates, alkyl, chloride, bromide, iodide, nitrate, and organic acid anions; B is preferably an alkoxy group; L is a solvent other than water;n a is any integer of 1, 2, 3, 4, 5 or 6, preferably 2 or 3; and b and c are any numbers obeying the formula b/2 + c = a, and c is 0.1b to 10b; d is a number between 0 and 0.8a, preferable between 0.1 and 0.3a; e is (a-c+f)/2; f is a number between 0 and (a-c); and x is between 0 and 6. |