PtO{sub}x/C based Catalysts with high metal loading for oxygen reduction in PEM fuel cells

摘要

A great deal of recent research has centered around the development of new methods for the preparation of nanosized transition metal colloids. The most common methods involve the reduction of appropriate metal salts in the presence of stabilizers such as polymers, surfactants, or special ligands which prevent undesired formation of insoluble bulk metal. Less is known concerning the respective metal oxides in the form of nanosized particles. We have previously shown that treatment of PtCl{sub}4 (or H{sub}2PtCl{sub}6) with such bases as NaOH, Na{sub}2CO{sub}3, or Li{sub}2CO{sub}3 in the presence of water-soluble betaine stabilizers results in the formation of stable aqueous solutions of colloidal PtO{sub}2 having a particle size of 1.8 nm. More recently we showed that the synthesis of carbon supported platinum oxide and platinum alloys is also possible without stabilizing tensids if the hydrolysis is carried out in presence of carbon black.