Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Topics in Catalysis

DOI:https://doi.org/10.1007/s11244-007-9001-z· OSTI ID:930892

Nilekar, Anand Udaykumar ^[1]; Xu, Ye ^[2]; Zhang, Junliang ^[3]; Vukmirovic, Miomir B. ^[3]; Sasaki, Kotaro ^[3]; Adzic, Radoslav R. ^[3]; Mavrikakis, Manos ^[1]

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1. University of Wisconsin, Madison
2. ORNL
3. Brookhaven National Laboratory (BNL)

Using a combination of density functional theory (DFT) calculations and an array of experimental techniques including in-situ x-ray absorption spectroscopy, we identified, synthesized, and tested successfully a new class of electrocatalysts for the oxygen reduction reaction (ORR) that were based on monolayers of Pt deposited on different late transition metals (Au, Pd, Ir, Rh, or Ru), of which the Pd-supported Pt monolayer had the highest ORR activity. The amount of Pt used was further decreased by replacing part of the Pt monolayer with a third late transition metal (Au, Pd, Ir, Rh, Ru, Re, or Os). Several of these mixed Pt monolayers deposited on Pd single crystal or on carbon-supported Pd nanoparticles exhibited up to a 20-fold increase in ORR activity on a Pt-mass basis when compared with conventional all-Pt electrocatalysts. DFT calculations showed that their superior activity originated from the interaction between the Pt monolayer and the Pd substrate and from a reduced OH coverage on Pt sites, the result of enhanced destabilization of Pt-OH induced by the oxygenated third metal. This new class of electrocatalysts promises to alleviate the major problems of existing fuel cell technology by simultaneously decreasing materials cost and enhancing performance.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 930892
• Journal Information: Topics in Catalysis, Vol. 46, Issue 3-4
• Country of Publication: United States
• Language: English