In U.S. Patent 7,642,217, Samsung SDI Co., Ltd. (Suwon-si, KR) reveals a platinum (Pt)/ruthenium (Ru) alloy catalyst with a lattice constant of 3.856-3.885 .ANG. and a particle size of 2-5 nanometers supported on a nano-carbon carrier. According to inventors Seol-ah Lee, Chan-ho Pak and Dae-Jung Yoo, the Pt/Ru alloy catalyst is highly resistant to CO poisoning, thereby allowing for higher catalytic activity when used. That is, an electrode and a methanol fuel cell having a longer lifetime can be prepared using a smaller amount of the Pt/Ru alloy catalyst.
Examples of a carrier supporting the Pt and Ru atoms include a carbon-based carrier, zeolite, and silica/alumina, etc., preferably a carbon-based carrier and zeolite. Examples of the carbon-based carrier include graphite, carbon powders, acetylene black, carbon black, activated carbon, mesoporous carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, carbon nanorings, carbon nanowires, or fullerene (C60).
A total concentration of Pt and Ru may be 60-80% by weight of the Pt/Ru alloy supported catalyst. If the total concentration of Pt and Ru is less than 60% by weight of the Pt/Ru alloy supported catalyst, a thickness of a catalytic layer in an anode increases, and thus an electrical resistance excessively increases. If the total concentration of Pt and Ru is greater than 80% by weight of the Pt/Ru alloy supported catalyst, the catalyst particles are agglomerated, and thus the specific surface area decreases and the utilization efficiency of the catalyst decreases.
FIG. 1 is a schematic view illustrating a mechanism that a Pt/Ru alloy nano-catalyst exhibits a resistance to CO poisoning;
FIG. 2 is a flow diagram illustrating a method of preparing the Pt/Ru alloy nano-catalyst by Samsung's Method
FIG. 3A is a transmission electron microscopic (TEM) image of a Pt/Ru alloy nano-catalyst and
FIG. 3B is a TEM image of a Pt/Ru alloy nano-catalyst by Samsung’s method
FIG. 1 is a schematic view illustrating a mechanism that a Pt/Ru alloy nano-catalyst exhibits a resistance to CO poisoning;
FIG. 2 is a flow diagram illustrating a method of preparing the Pt/Ru alloy nano-catalyst by Samsung's Method
FIG. 3A is a transmission electron microscopic (TEM) image of a Pt/Ru alloy nano-catalyst and
FIG. 3B is a TEM image of a Pt/Ru alloy nano-catalyst by Samsung’s method
