UCLA researchers in the Department of Materials Science and Engineering have developed multimetallic PtNiCuMo nano octahedral catalyst that has demonstrated greatly improved mass activity, specific activity, and stability for application in fuel cells.
Fuel cell technology is considered as one of the promising alternatives to the internal combustion engines in automotive applications, which could substantially decrease reliance on fossil fuels. Inside a typical polymer electrolyte membrane fuel cell (PEMFC), the hydrogen fuel reacts with oxygen to generate electricity with water as the only product. However, the slow kinetics of the oxygen reduction reaction (ORR) on costly platinum cathode electrocatalysts represents a major obstacle for large-scale commercialization of fuel cells.
Bimetallic and multimetallic materials with a lower content of Pt metal not only inherit the properties of the Pt constituent, but also show a superior performance when compared with monometallic Pt. Single crystal surface of Pt3Ni(111) has shown 10 times higher specific activity than the corresponding Pt(111) surface and 90 times than the commercial Pt/C catalysts for the ORR. Molybdenum (Mo) surface-doped Pt3Ni nano octahedra supported on carbon demonstrated almost 80-fold higher specific activity, as well as improved stability than the commercial Pt/C catalysts for the ORR. Current researches in nano-scale Pt-based cathode electrocatalysts are focusing on materials with largely reduced content of Pt while still maintaining superior performance.
Researchers at UCLA have designed highly active and durable ORR catalyst by introducing Cu to the PtNiMo octahedral catalyst. The resulting PtNiCuMo showed outstanding specific activity and mass activity, that are about 45 times and 35 times higher than those of Pt/C catalysts. The octahedral nano structure of PtNiCuMo has also demonstrated exceptional stability as it retains 74% specific activity and 83% mass activity after 15,000 ADT cycles.
Successfully tested in the lab, and needs to be further tested in real fuel cell module for scale up and mass production.
|United States Of America||Published Application||20190190033||06/20/2019||2017-019|
Electrocatalyst, catalyst, polymer electrolyte membrane fuel cell (PEMFC), fuel cell, precious metal group (PMG), nanocrystals (NCs), nanocatalysts, oxygen reduction reaction (ORR), PtNi