Method for forming lanthanum hydroxycarbonate nanoparticles
AssigneeKing Fahd University of Petroleum and Minerals
InventorMd. Hasan Zahir
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Abstract
A hydrothermal method of preparing uniform, monodisperse ceramic lanthanum hydroxyl carbonate (LaCO3OH) having cherry-blossom-like nanogears and/or nanocubes is described. The method produced a hexagonal crystal with a crystal lattice in which at least on lanthanum ion is substituted with calcium ion. The ceramic nanoparticles produced by the method are good catalyst for the reduction of nitrogen oxides with a hydrocarbon. A method of reducing exhaust gases is described.
Claims10
A method of forming lanthanum hydroxycarbonate nanoparticles having a crystal lattice structure, wherein at least one lanthanum cation of the crystal lattice structure is substituted with a calcium cation, said method comprising:
- hydrothermally treating an aqueous reaction mixture comprising water, a calcium salt, a lanthanum salt, and an ammonium carbonate salt at a temperature of 120 to 250° C. for a time of 12-60 hours to form the ceramic nanoparticles, wherein a molar ratio of lanthanum to calcium is in the range of 80:20 to 99:1 and wherein during the hydrothermal treatment the ammonium carbonate is added to the reaction mixture in an amount sufficient to maintain a pH of about 8.5.
Dependencies are inferred from the claim text.