Metal and Metal Oxide-Supported Platinum Monolayer Electrocatalysts for Oxygen Reduction

 

Research is directed towards the synthesis and characterization of Pt monolayer electrocatalysts supported by metal, metal alloy, non-noble metal - noble metal core - shell and oxide nanoparticles, or single crystal extended surfaces. This new approach has the potential to yield electrocatalysts with the lowest Pt content and improved catalytic activity, which can reduce the cost of fuel cells. In a parallel effort we are developing new improved Pd alloy electrocatalysts that can replace Pt in fuel cell cathodes. The structural, electronic and catalytic properties of electrocatalysts for O2 reduction, methanol, ethanol and CO oxidation reactions are studied by in situ and ex situ synchrotron radiation, surface science, infrared and electrochemical techniques. The synthesis of Pt monolayer electrocatalysts is based on the unique method that involves a Pt monolayer deposition by displacement of an adsorbed Cu monolayer. Understanding the phenomena which determine the catalytic properties, structure-activity correlations, catalysts’ stability, segregation, structure and ordering of atomic and molecular monolayers at electrochemical interfaces is sought by combining the above techniques and kinetic analyses of the O2 reduction reaction with intensive density functional theory calculations.
 

Research Activities:

Electrocatalysis


1. Pt monolayer Electrocatalysts for O2 reduction: atomic-level synthesis, Electronic properties of Pt monolayers on single crystals and nanoparticles, Pt-support interactions; Structure-activity correlations; Pd alloy electrocatalysts; In situ spectroscopic studies of the O2 reduction intermediates; Kinetic analyses of the O2 reduction reaction.

                                                                                   Pt monolayer cathode electrocatalysts
                                                       structure activity stability

 

fuel cell test

 
   
The first Pt monolayer-level electrocatalyst. No change in performance during ca. 900 hours as anode under fuel cell operating conditions

2. Pt submonolayer on Ru (PtRu20) Electrocatalysts: H2, CO and reformate H2 oxidation; Pt content is 1/10 of that in commercial catalysts, high CO tolerance; Oxidation of Methanol and Ethanol; Adsorbate-Surface Interactions.

Research Activities

Surface Electrochemistry: To obtain a true microscopic description of electrochemical interfaces, structural and electronic properties of atomic and molecular monolayers on single-crystal and nanoparticle substrates are investigated using in situ scanning tunneling microscopy, surface x-ray scattering and x-ray absorption spectroscopy.

 

Recent Publications

 

 

1.      B. Vukmirovic J. Zhang, K. Sasaki, F. Uribe, M. Mavrikakis, R. R. Adzic. Platinum Monolayer Electrocatalysts for Oxygen Reduction,  Electrochim. Acta, 52 (2007) 2257.

 

2.      J. Zhang, K. Sasaki, E. Sutter, R. R. Adzic, Stabilization of Platinum Oxygen Reduction Electrocatalysts Using Gold Clusters, Science, 315 (2007) 220. 
 

3.      R. R. Adzic, J. Zhang, K. Sasaki, M. B. Vukmirovic, M. Shao, J.X. Wang, A.U. Nilekar, Mavrikakis, J. A. Valerio, F. Uribe, Platinum Monolayer Fuel Cell Electrocatalysts, Topics in Catalysis, 46 (2007) 249-262.

 

4.      M. Shao, K. Sasaki, N. S. Marinkovic, L. Zhang, R. R. Adzic, Synthesis and Characterization of Platinum Monolayer Oxygen-Reduction Electrocatalysts with Co-Pd Core-Shell Nanoparticle Supports,  Electrochem. Comm., 9 (2007) 2848-2853.

 

5.      J. X. Wang, J. Zhang, R. R. Adzic, Dual-Trap Kinetic Equation for the Oxygen Reduction Oxidation Reaction on Pt (111) in Acidic Media, J. Phys. Chem. A, 111 (2007) 12702 - 12710.

 

6.      A. Kowal, M. Li, M. Shao, K. Sasaki, M.B. Vukmirovic, J. Zhang, N. S. Marinkovic, P. Liu, A.I. Frenkel, R. R. Adzic, Ternary Pt/Rh/SnO2 Electrocatalysts for Oxidizing Ethanol to CO2, Nature Materials, (2009) 8- 325.

 

7.      J. X. Wang, H. Inada, L. Wu, Y. Zhu, Y. Choi, P. Liu, W-P. Zhou, and R. R. Adzic, Oxygen reduction on well-defined core-shell nanoparticles:Size, facet, and Pt shell thickness effects, J. Am. Chem. Soc., 131 (2009) 17298.

 

8.      Kuanping Gong, Dong Su, Radoslav R. Adzic Platinum-Monolayer Shell on AuNi0.5Fe Nanoparticle Core Electrocatalyst with High Activity and Stability for the Oxygen Reduction Reaction, J. Am. Chem. Soc. Web.

 

9.      K. Sasaki, Y. Cai, Dr. Y. Choi, P. Liu, Dr. M. B. Vukmirovic, Dr. J. X. Wang, and Dr. R. R. Adzic, Core-protected Core-shell Electrocatalysts: Potential for Automotive Applications of Fuel Cells, Angewandte Chemie Intern. web.

 

10.  Platinum Monolayer Electrocatalysts for Fuel Cells, R. R. Adzic, F. Lima, in Handbook of Fuel Cells, Vol. 5 –Advances in Electrocatalysis, Materials, Diagnostics and Durability, Eds. W. Vielstich, H. A. Gasteiger, H. Yokokawa pp 5-18, J. Wiley & Sons, New York, 2009.

 

 

 

 

 

 

Supported by the the Division of Chemical Sciences, Geosciences, and Biosciences of the Office of Basic Energy Sciences of the Office of Science under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

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Last Modified: June 28, 2012