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.

Wel­come to HEL – Bet­ter Chem­istry – Faster

2014 Spring Symposium

 


 
HEL is a lead­ing equip­ment provider for cat­alyt­ic process­es in chem­i­cal, petro­chem­i­cal and phar­ma­ceu­ti­cal Indus­try. Stirred and fixed-bed reac­tors for cat­alyt­ic & ther­mal con­ver­sions (hydro­gena­tion reac­tor, poly­mer­iza­tion, hydro­c­rack­ing, bio-fuel syn­the­sis etc.) are sup­plied to a range of indus­tries. Often at ele­vat­ed tem­per­a­ture & pres­sure, HEL spe­cial­izes in research scale, mul­ti-reac­tor and high pres­sure reac­tors pro­cess­ing, test­ing, equip­ment and sys­tems. Cus­tom designs to client flow sheets are also sup­plied includ­ing pilot scale process­es.

Life Cycle of Cat­alytic Diesel Emis­sion Con­trol Sys­tems

2014 Spring Symposium

 
Alek­sey Yez­erets, Neal Cur­ri­er, Krish­na Kamasamu­dram, Jun­hui Li, Hong­mei An, Ashok Kumar, Jiny­ong Luo, Saurabh Joshi


 
Abstract — A diverse spec­trum of high­ly capa­ble diesel cat­alyt­ic emis­sion con­trol sys­tems has emerged in the recent years, in response to strin­gent envi­ron­men­tal reg­u­la­tions in sev­er­al lead­ing world mar­kets. By tak­ing the brunt of the emis­sion reduc­tion, these high­ly effec­tive sys­tems allowed the engines to be designed and tuned for max­i­mum fuel effi­cien­cy and min­i­mum CO2 emis­sions.

Unlike their gaso­line emis­sion con­trol pre­de­ces­sors, diesel sys­tems include mul­ti­ple cat­a­lysts with dis­tinct func­tions, along with a vari­ety of sen­sors and actu­a­tors, thus rep­re­sent­ing ver­i­ta­ble chem­i­cal plants. For exam­ple, the emis­sion con­trol sys­tem com­mer­cial­ized in Cum­mins-pow­ered 2010 heavy-duty diesel vehi­cles includes four dis­tinct cat­alyt­ic devices, a diesel oxi­da­tion cat­a­lyst (DOC), cat­alyzed diesel par­tic­u­late fil­ter (DPF), selec­tive cat­alyt­ic reduc­tion (SCR) cat­a­lyst, and an ammo­nia slip selec­tive oxi­da­tion cat­a­lyst (ASC). The sys­tem fur­ther includes eight sen­sors, and two flu­id injec­tors, along with the respec­tive con­trols and diag­nos­tic algo­rithms. Anoth­er sys­tem, com­mer­cial­ized by Cum­mins in 2007 and 2010 Dodge Ram pick­ups, is based on a NOx adsor­ber cat­a­lyst and rep­re­sents sim­i­lar lev­el of sophis­ti­ca­tion. Under­ly­ing the sys­tem-lev­el com­plex­i­ty is the intri­ca­cy of the indi­vid­ual cat­alyt­ic ele­ments, some of which include mul­ti­ple dis­tinct chem­i­cal func­tions and com­plex topol­o­gy.

Pre­dictably, life­cy­cles of such sys­tems are shaped by the behav­iors of the indi­vid­ual cat­alyt­ic ele­ments and their inter­ac­tions. These often fea­ture a vari­ety of reversible process­es, in response to depo­si­tion and removal of var­i­ous poi­sons and mask­ing agents, reversible chem­i­cal and mor­pho­log­i­cal changes, along with irre­versible degra­da­tion, often referred to as aging.

In this pre­sen­ta­tion, we will review sev­er­al exam­ples of inter­ac­tions between cat­a­lysts in the con­text of the above diesel emis­sion con­trol sys­tems, empha­siz­ing how the recent advances in their prac­ti­cal appli­ca­tion were under­pinned by the devel­op­ments in the broad­er field of het­ero­ge­neous catal­y­sis and reac­tion engi­neer­ing.
 
Aleksey_YezeretsBiog­ra­phy — At Cum­mins, the world’s largest inde­pen­dent man­u­fac­tur­er of diesel engines and relat­ed equip­ment, Dr. Yez­erets leads an R&D team respon­si­ble for guid­ance and sup­port of emis­sion con­trol prod­ucts at all stages of their life­cy­cle, and coor­di­nates a port­fo­lio of col­lab­o­ra­tive research pro­grams with Nation­al Labs, uni­ver­si­ties and indus­tri­al part­ners. Dr. Yez­erets serves on the Edi­to­r­i­al Board of the Jour­nal of Applied Catal­y­sis B: Envi­ron­men­tal, has act­ed as a guest edi­tor of three issues of the Catal­y­sis Today Jour­nal, and orga­nized a num­ber of envi­ron­men­tal catal­y­sis ses­sions in indus­tri­al and aca­d­e­m­ic meet­ings. He has received 11 US patents, pub­lished over 50 peer-reviewed arti­cles, as well as pre­sent­ed numer­ous invit­ed, keynote, and award lec­tures. Dr. Yez­erets has a spe­cial appoint­ment to the Grad­u­ate Fac­ul­ty of Chem­i­cal Engi­neer­ing at Pur­due Uni­ver­si­ty. His con­tri­bu­tions to the field of cat­alyt­ic emis­sion con­trol were rec­og­nized by the Her­man Pines Award in Catal­y­sis, R&D 100 Award, nation­al awards by the Amer­i­can Chem­i­cal Soci­ety, Amer­i­can Insti­tute of Chem­i­cal Engi­neers, and Soci­ety Auto­mo­tive Engi­neer­ing, as well as Julius Perr Award for Inno­va­tion by Cum­mins.

Renewable production of phthalic anhydride from biomass-derived furan and maleic anhydride

Meeting Program — January 2014

 
Eyas Mah­moud†, Don­ald A. Wat­son‡ and Raul F. Lobo†
†Catal­y­sis Cen­ter for Ener­gy Inno­va­tion
Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing
Uni­ver­si­ty of Delaware
Newark, DE 19716 USA
 
‡Depart­ment of Chem­istry and Bio­chem­istry
Uni­ver­si­ty of Delaware
Newark, DE 19716 USA

 
Abstract — A route to renew­able phthal­ic anhy­dride (2-benzofuran-1,3-dione) from bio­mass-derived furan and male­ic anhy­dride (furan-2,5-dione) is inves­ti­gat­ed. Furan and male­ic anhy­dride were con­vert­ed to phthal­ic anhy­dride in two reac­tion steps: Diels Alder cycload­di­tion fol­lowed by dehy­dra­tion. Excel­lent yields for the Diels-Alder reac­tion between furan and male­ic-anhy­dride were obtained at room tem­per­a­ture and sol­vent-free con­di­tions (SFC) yield­ing 96% exo-4,10-Dioxa-tricyclo[5.2.1.0]dec-8-ene-3,5-dione (oxanor­bornene dicar­boxylic anhy­dride) after 4 hrs of reac­tion. It is shown that this reac­tion is resis­tant to ther­mal run­away because its reversibil­i­ty and exother­mic­i­ty. The dehy­dra­tion of the oxanor­bornene was inves­ti­gat­ed using mixed-sul­fon­ic car­boxylic anhy­drides in methane­sul­fon­ic acid (MSA). An 80% selec­tiv­i­ty to phthal­ic anhy­dride (87% selec­tiv­i­ty to phthal­ic anhy­dride and phthal­ic acid) was obtained after run­ning the reac­tion for 2 hrs at 298 K to form a sta­ble inter­me­di­ate fol­lowed by 4 hrs at 353 K to dri­ve the reac­tion to com­ple­tion. The struc­ture of the inter­me­di­ate was deter­mined. This result is much bet­ter than the 11% selec­tiv­i­ty obtained in neat MSA using sim­i­lar reac­tion con­di­tions.
 
Biog­ra­phy — Eyas Mah­moud, recip­i­ent of the AIChE SCI Schol­ar award, grad­u­at­ed sum­ma cum laude from from the Uni­ver­si­ty of Penn­syl­va­nia with a B.S.E.in Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing in 2011. Since then he received the NSF Grad­u­ate Research Fel­low­ship (GRFP) and went on to pur­sue a Ph.D. in the Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing from the Uni­ver­si­ty of Delaware, under the super­vi­sion of Pro­fes­sor Raul F. Lobo. His the­sis work focus­es on the renew­able pro­duc­tion of aro­mat­ics from bio­mass-feed­stocks. Recent­ly, he has pub­lished work on the renew­able pro­duc­tion of phthal­ic anhy­dride from furan and male­ic anhy­dride by using mixed sul­fon­ic-car­boxylic anhy­drides.

Thermodynamics and kinetics of elementary reaction steps on late transition metal catalysts, and using them to search for better catalysts

Meeting Program — November 2013

 
Charles T. Camp­bell
Depart­ments of Chem­istry and of Chem­i­cal Engi­neer­ing
Uni­ver­si­ty of Wash­ing­ton
Seat­tle, WA 98195–1700

 
Abstract — A sur­vey of exper­i­men­tal and the­o­ret­i­cal results con­cern­ing the ther­mo­dy­nam­ics and kinet­ics of sur­face chem­i­cal reac­tions of impor­tance in late tran­si­tion met­al catal­y­sis for ener­gy tech­nol­o­gy will be pre­sent­ed. Top­ics include: (1) calori­met­ric mea­sure­ments of the adsorp­tion ener­gies of small mol­e­cules and mol­e­c­u­lar frag­ments on sin­gle crys­tal sur­faces, and their com­par­i­son to DFT results; (2) new mea­sure­ments of the entropies of adsor­bates and the trends they fol­low, and (3) new ways to esti­mate pref­ac­tors in the rate con­stants for ele­men­tary steps in sur­face reac­tions. We will also dis­cuss how to use these togeth­er with DFT cal­cu­la­tions and/or ele­men­tary-step rate mea­sure­ments to build micro­ki­net­ic mod­els for mul­ti-step cat­alyt­ic reac­tions. Final­ly, we will dis­cuss a method for ana­lyz­ing these to quan­ti­fy the extent to which each ele­men­tary step and inter­me­di­ate con­trols the net rate, and describe how one can use this to define the key descrip­tors that can be used for com­pu­ta­tion­al search­es to dis­cov­er bet­ter cat­a­lyst mate­ri­als.
 
Charles_Campbell2-1024x853Biog­ra­phy — Charles T. Camp­bell is the Rabi­novitch Endowed Chair in Chem­istry at the Uni­ver­si­ty of Wash­ing­ton, where he is also Adjunct Pro­fes­sor of Chem­i­cal Engi­neer­ing and of Physics. He is the author of over 270 pub­li­ca­tions on sur­face chem­istry, catal­y­sis and biosens­ing. He is an elect­ed Fel­low of both the ACS and the AAAS, and Mem­ber of the Wash­ing­ton State Acad­e­my of Sci­ences. He received the Arthur W. Adam­son Award of the ACS and the ACS Award for Col­loid or Sur­face Chem­istry, the Ger­hard Ertl Lec­ture Award, the Robert Bur­well Award/Lectureship of the North Amer­i­can Catal­y­sis Soci­ety, the Ipati­eff Lec­ture­ship at North­west­ern Uni­ver­si­ty and an Alexan­der von Hum­boldt Research Award. He served as Chair, Chair-Elect, Vice-Chair and Trea­sur­er of the Col­loid and Sur­face Chem­istry Divi­sion of the ACS. He served as found­ing Co-Direc­tor and Direc­tor of the Uni­ver­si­ty of Washington’s Cen­ter for Nan­oTech­nol­o­gy, and as Edi­tor-in-Chief of the jour­nal Sur­face Sci­ence for ten years. He is cur­rent­ly Edi­tor-in-Chief of Sur­face Sci­ence Reports, and serves on the Edi­to­r­i­al Boards of the Jour­nal of Phys­i­cal Chem­istry and Catal­y­sis Reviews and the Sci­en­tif­ic Advi­so­ry Board of Catal­y­sis Let­ters and Top­ics in Catal­y­sis. He received his B.S. in Chem­i­cal Engi­neer­ing (1975) and his Ph.D. in Phys­i­cal Chem­istry (1979, under J. M. White) from the Uni­ver­si­ty of Texas at Austin, and then did research in Ger­many under Ger­hard Ertl (2007 Nobel Prize Win­ner) through 1980.

Developing Ceria-Based Catalysts

Meeting Program — October 2013

 
Ray­mond J. Gorte
Depart­ment of Chem­i­cal & Bio­mol­e­c­u­lar Engi­neer­ing
Uni­ver­si­ty of Penn­syl­va­nia
Philadel­phia, PA 19104

 
Abstract — Ceria-sup­port­ed met­al cat­a­lysts are wide­ly used in auto­mo­tive emis­sions con­trol, where ceria pro­vides “Oxy­gen Stor­age Capac­i­tance”. Ceria-sup­port­ed met­als also have poten­tial for a large num­ber of oth­er appli­ca­tions, rang­ing from methane oxi­da­tion to the water-gas-shift reac­tion, due to the enhanced prop­er­ties that ceria imparts. How­ev­er, the activ­i­ties and sta­bil­i­ties depend strong­ly on the struc­ture of the ceria and whether or not it is mixed with a sec­ond oxide. Cat­a­lyst prop­er­ties are also affect­ed by how cat­alyt­ic met­als inter­act with the sup­port.

In this talk, I will first dis­cuss work aimed at under­stand­ing the role that ceria plays in oxy­gen stor­age and demon­strate that the ther­mo­dy­nam­ic redox prop­er­ties of cat­alyt­ic forms of ceria dif­fer from that of bulk ceria. I will then talk about our efforts to max­i­mize the inter­ac­tions between cat­alyt­ic met­als and ceria, as well as pre­vent sin­ter­ing of the met­al par­ti­cles, through the prepa­ra­tion of core-shell cat­a­lysts deposit­ed onto a func­tion­al­ized-alu­mi­na sup­port. These core-shell cat­a­lysts exhib­it excep­tion­al activ­i­ty for methane oxi­da­tion, with impres­sive sta­bil­i­ty at high tem­per­a­tures.
 
ray_gorteBiog­ra­phy — Ray­mond J. Gorte joined the fac­ul­ty at the Uni­ver­si­ty of Penn­syl­va­nia in 1981 after receiv­ing his PhD in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Min­neso­ta. He is cur­rent­ly the Rus­sell Pearce and Eliz­a­beth Crim­i­an Heuer Pro­fes­sor of Chem­i­cal & Bio­mol­e­c­u­lar Engi­neer­ing, with a sec­ondary appoint­ment in Mate­ri­als Sci­ence & Engi­neer­ing. Since join­ing Penn, Ray has served as Chair­man of Chem­i­cal Engi­neer­ing from 1995 to 2000 and was the Carl V. S. Pat­ter­son Pro­fes­sor of Chem­i­cal Engi­neer­ing from 1996 through 2001. He received the 1997 Par­ra­vano Award of the Michi­gan Catal­y­sis Soci­ety, the 1998 Philadel­phia Catal­y­sis Club Award, the 1999 Paul Emmett Award of the North Amer­i­can Catal­y­sis Soci­ety, the 2001 Penn Engi­neer­ing Dis­tin­guished Research Award, and the 2009 AIChE Wil­helm Award. He has served as Chair­man of the Gor­don Con­fer­ence on Catal­y­sis (1998) and Pro­gram Chair­man of the 12th Inter­na­tion­al Zeo­lite Con­fer­ence (1998). He is an Asso­ciate Edi­tor of the Jour­nal of the Elec­tro­chem­i­cal Soci­ety. His present research inter­ests are focused on elec­trodes for sol­id-oxide fuel cells and the cat­alyt­ic prop­er­ties of core-shell mate­ri­als. He is also known for his research on zeo­lite acid­i­ty and for met­al-sup­port effects, espe­cial­ly with ceria-sup­port­ed pre­cious met­als, used in auto­mo­tive emis­sions con­trol.