Patent ID: 8337799
Filing Date: 2012-12-25
Classification: B82Y,C01B,C01P,C09C,Y10T

Abstract:
1. A process for manufacturing nanoparticles of at least one oxide of a transition metal selected from the group consisting of Ti, Zr, Hf, V, Nb and Ta, which are coated with amorphous carbon, said process comprising the following consecutive steps: (i) preparing a liquid mixture containing as precursors at least one alkoxide of said transition metal, an alcohol, acetic acid in excess with respect to said transition metal, and then diluting the mixture in water so as to form an aqueous solution, said precursors being present in said aqueous solution in a molar ratio so as to prevent or restrict the formation of a sol so that said aqueous solution can be lyophilized, and such that said transition metal, the carbon and the oxygen are present in the aqueous solution in the same stoichiometric ratio in which they are found in said nanoparticles, (ii) subjecting said aqueous solution to lyophilization, (iii) pyrolyzing the lyophilizate obtained in the previous step, under vacuum or an inert atmosphere to obtain said nanoparticles.