Highly stable Pt monolayer on PdAu nanoparticle electrocatalysts for the oxygen reduction reaction

• DOI: 10.1038/ncomms2124
• Publication Date: 2012-10-09T09:35:39Z
• Authors: Kotaro Sasaki; Hideo Naohara; YongMan Choi; Yun Cai; Wei-Fu Chen; Ping Liu; Radoslav R. Adzic
• Keywords: Electrochemistry; Nanotechnology; Gold; 02 engineering and technology; 0210 nano-technology; Oxidation-Reduction; 7. Clean energy; Catalysis; Palladium; Platinum

Stability is one of the main requirements for commercializing fuel cell electrocatalysts for automotive applications. Platinum is the best-known catalyst for oxygen reduction in cathodes, but it undergoes dissolution during potential changes while driving electric vehicles, thus hampering commercial adoption. Here we report a new class of highly stable, active electrocatalysts comprising platinum monolayers on palladium-gold alloy nanoparticles. In fuel-cell tests, this electrocatalyst with its ultra-low platinum content showed minimal degradation in activity over 100,000 cycles between potentials 0.6 and 1.0 V. Under more severe conditions with a potential range of 0.6-1.4 V, again we registered no marked losses in platinum and gold despite the dissolution of palladium. These data coupled with theoretical analyses demonstrated that adding a small amount of gold to palladium and forming highly uniform nanoparticle cores make the platinum monolayer electrocatalyst significantly tolerant and very promising for the automotive application of fuel cells.