Patent ID: 7829496

Claim:
A method for preparing a platinum based nano-size catalyst comprising the following steps: a) carrying out a reduction reaction of a platinum precursor which is chloroplatinic acid (H 2 PtCl 6 ), and an optional ad-metal precursor with a reducing agent in a solvent and in the presence of a stabilizer, in order to form a suspension containing colloidal particles of platinum or platinum/ad-metal; b) mixing the resulting suspension with a co-solvent which is a mixture of ethylene glycol and C 3 -C 12 aliphatic alkane or a mixture of ethylene glycol and toluene, to form a mixture; c) subjecting the resulting mixture to centrifugal treatment, thereby giving rise to platinum or platinum/ad-metal colloidal particle portion and a liquid portion; d) repeating the co-solvent mixing and centrifugal treatment to the platinum or platinum/ad-metal colloidal particle portion, until the resulting liquid portion substantially does not contain chloride ions as a product of the reduction reaction; and e) drying the platinum or platinum/ad-metal colloidal particle portion to obtain a platinum based nano-size catalyst, wherein the reducing agent, solvent, and stabilizer of step a) is ethylene glycol.