Analy­sis of the Mech­a­nism of Elec­tro­chem­i­cal Oxy­gen Reduc­tion and Devel­op­ment of Ag– and Pt-alloy Cat­a­lysts for Low Tem­per­a­ture Fuel Cells

2014 Spring Symposium

 
Suljo Linic

 
Abstract – The oxygen reduction reaction (ORR) is the major source of overpotential loss in low-temperature fuel cells. Expensive, Pt-based materials have been found to be the most effective catalysts, but exploration of alternatives has been hampered by stability constraints at the typical operating conditions of low pH and high potential.

I will discuss how we studied elementary mechanism of ORR on various metal electrodes using kinetic and micro-kinetic analysis of reaction pathways and quantum chemical calculations. These studies allowed us to identify the elementary steps and molecular descriptors that govern the rate of ORR. Using these performance descriptors we have been able to identify families of Pt and Ag-based alloys that exhibit superior ORR performance is acid and base respectively.

We have synthesized these alloys to demonstrate the superior ORR activity with rotating disk electrode experiments. We have also performed thorough structural characterization of the bulk and surface properties with a combination of cyclic voltammetry, x-ray diffraction, and electron microscopy with spatially resolved energy-dispersive x-ray spectroscopy and electron energy loss spectroscopy.
 

Reference

  1. Holewinski and Linic. J. Electrochem. Soc. 159, (2012).

 
Suljo_LinicBiography – Prof. Linic obtained his PhD degree, specializing in surface and colloidal chemistry and heterogeneous catalysis, at the University of Delaware in 2003 under the supervision of Prof. Mark Barteau after receiving his BS degree in Physics with minors in Mathematics and Chemistry from West Chester University in West Chester (PA). He was a Max Planck postdoctoral fellow with Prof. Dr. Matthias Scheffler at the Fritz Haber Institute of Max Planck Society in Berlin (Germany), working on first principles studies of surface chemistry. He started his independent faculty career in 2004 at the Department of Chemical Engineering at the University of Michigan in Ann Arbor where he is currently the Class of 1983 Faculty Scholar Professor of chemical engineering.

Prof. Linic’s research has been recognized through multiple awards including the 2014 ACS (American Chemical Society) Catalysis Lectureship for the Advancement of Catalytic Science, awarded annually by the ACS Catalysis journal and Catalysis Science and Technology Division of ACS, the 2011 Nanoscale Science and Engineering Forum Young Investigator Award, awarded by American Institute of Chemical Engineers, the 2009 ACS Unilever Award awarded by the Colloids and Surface Science Division of ACS, the 2009 Camille Dreyfus Teacher-Scholar Award awarded by the Dreyfus Foundation, the 2008 DuPont Young Professor Award, and a 2006 NSF Career Award. Prof. Linic has presented more than 100 invited and keynote lectures and published more than 50 peer reviewed articles in leading journals in the fields of general science, Physics, Chemistry, and Chemical Engineering.