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.