Designing and Probing Photovoltaic and Photocatalytic Materials

Meeting Program — November 2012

 
Jason B. Bax­ter
Depart­ment of Chem­i­cal and Bio­log­i­cal Engi­neer­ing
Drex­el Uni­ver­si­ty
Philadel­phia, PA
 
Abstract — The sun­light inci­dent on the earth pro­vides 10,000 times more pow­er than is need­ed to meet glob­al demand. How­ev­er, con­vert­ing this ener­gy into elec­tric­i­ty or fuels effi­cient­ly and cost effec­tive­ly remains a great chal­lenge. Nanos­truc­tured solar cells present oppor­tu­ni­ties to inex­pen­sive­ly con­vert sun­light to elec­tric­i­ty through the use of archi­tec­tures tai­lored on the nanome­ter to microm­e­ter length scale. Pla­nar solar cells are sub­ject to oppos­ing con­straints where thick films are required for light absorp­tion while thin­ner films are desir­able for effi­cient charge sep­a­ra­tion. Extreme­ly thin absorber (ETA) solar cells can decou­ple these con­straints by using a thin absorber at the inter­face between high­ly struc­tured p- and n-type lay­ers. In this talk, I will describe our work on ETA solar cells that use a thin CdSe coat­ing on a ZnO nanowire array to absorb light and inject elec­trons into the oxide. Ratio­nal design of these archi­tec­tures requires con­trol over mor­phol­o­gy and microstruc­ture of the mate­ri­als, as well as knowl­edge of mate­r­i­al prop­er­ties such as pho­toex­cit­ed car­ri­er life­times and mobil­i­ties. Our approach uti­lizes a com­bi­na­tion of solar cell mea­sure­ments and ultra­fast tran­sient absorp­tion spec­troscopy to under­stand the effects of CdSe thick­ness, anneal­ing con­di­tions, and inter­fa­cial treat­ments on the dynam­ics and effi­cien­cy of charge car­ri­er sep­a­ra­tion, and ulti­mate­ly on the solar-to-elec­tric ener­gy con­ver­sion effi­cien­cy. These stud­ies pro­vide guide­lines for archi­tec­ture design and mate­ri­als selec­tion for ETA solar cells.
 

Jason B. Baxter

Jason B. Bax­ter

Biog­ra­phy — Dr. Jason B. Bax­ter is an Assis­tant Pro­fes­sor in the Depart­ment of Chem­i­cal and Bio­log­i­cal Engi­neer­ing at Drex­el Uni­ver­si­ty in Philadel­phia, PA, where he began in 2007. He received his B.Ch.E. from the Uni­ver­si­ty of Delaware in 2000, where he did under­grad­u­ate research on dye sen­si­tized solar cells at the Insti­tute of Ener­gy Con­ver­sion under the guid­ance of Prof. T.W. Fras­er Rus­sell. He earned his Ph.D. in chem­i­cal engi­neer­ing from the Uni­ver­si­ty of Cal­i­for­nia San­ta Bar­bara in 2005. Advised by Prof. Eray S. Aydil and fund­ed by an NSF Grad­u­ate Research Fel­low­ship, he inves­ti­gat­ed growth and char­ac­ter­i­za­tion of ZnO nanowires and their appli­ca­tion in dye sen­si­tized solar cells. From 2005–2007, Dr. Bax­ter was an ACS Petro­le­um Research Fund Alter­na­tive Ener­gy Post­doc­tor­al Fel­low at Yale Uni­ver­si­ty. There he worked with Prof. Charles A. Schmut­ten­maer in the Chem­istry Depart­ment on the appli­ca­tion of time-resolved ter­a­hertz spec­troscopy to probe tran­sient pho­to­con­duc­tiv­i­ty in oxide thin films, nanopar­ti­cles, nanowires, and bulk crys­tals.

Dr. Baxter’s cur­rent research inter­ests are in design­ing, fab­ri­cat­ing, and prob­ing semi­con­duc­tor nano­ma­te­ri­als and thin films for solar ener­gy con­ver­sion. Most cur­rent efforts focus on solar-to-elec­tric ener­gy con­ver­sion, but the group has grow­ing inter­est in pho­to­cat­alyt­ic water split­ting for clean and renew­able hydro­gen pro­duc­tion. Var­i­ous projects in the group include extreme­ly thin absorber solar cells, organ­ic solar cells, microre­ac­tor depo­si­tion of grad­ed thin films for high-through­put char­ac­ter­i­za­tion, and ultra­fast pump-probe spec­troscopy to mea­sure charge car­ri­er dynam­ics. The gen­er­al focus of the group is on striv­ing to under­stand how mate­ri­als and inter­faces affect device per­for­mance, and how these mate­ri­als and inter­faces can be con­trolled dur­ing the fab­ri­ca­tion process. Low-tem­per­a­ture solu­tion pro­cess­ing meth­ods are used when­ev­er pos­si­ble to pro­vide a path­way to low-cost, scal­able man­u­fac­tur­ing.
Dr. Bax­ter advis­es a group of 4 PhD stu­dents, 2 MS stu­dents, and 8 BS stu­dents. He has pub­lished near­ly 25 papers, which have col­lec­tive­ly gar­nered well over 1000 cita­tions. He has been award­ed over $1 mil­lion in fund­ing as lead inves­ti­ga­tor and anoth­er $3 mil­lion as co-inves­ti­ga­tor. He received the NSF CAREER Award in 2009.

Pervasiveness of Surface Metal Oxide Phases In Mixed Oxide Catalysts

Meeting Program — October 2012

 
Israel E. Wachs
Operan­do Mol­e­c­u­lar Spec­troscopy & Catal­y­sis Lab­o­ra­to­ry
Depart­ment of Chem­i­cal Engi­neer­ing
Lehigh Uni­ver­si­ty
Beth­le­hem, PA 18015 USA
 
Abstract — Mixed oxide cat­alyt­ic mate­ri­als pos­sess two or more met­al oxide com­po­nents as found in bulk mixed met­al oxides (sto­i­chio­met­ric oxides as well as sol­id solu­tions), poly­oxo meta­lates (POMs), mol­e­c­u­lar sieves, zeo­lites, clays, hydro­tal­cites and sup­port­ed met­al oxides. Although it is now well estab­lished that two-dimen­sion­al sur­face met­al oxide phas­es are present for sup­port­ed met­al oxides on tra­di­tion­al sup­ports (e.g., Al2O3, TiO2, ZrO2, SiO2, etc.), it is not cur­rent­ly appre­ci­at­ed that such sur­face met­al oxide species or phas­es are also present for oth­er types of mixed oxides. For exam­ple, recent sur­face analy­ses have demon­strat­ed that sto­i­chio­met­ric bulk mixed met­al oxides also pos­sess sur­face met­al oxide phas­es that con­trol their cat­alyt­ic activ­i­ty. For exam­ple, the cat­alyt­ic active sites for methanol oxi­da­tion to formalde­hyde over the bulk Fe2(MoO4)3 mixed oxide cat­a­lyst are sur­face MoOx species and not the bulk Fe2(MoO4)3 phase as pre­vi­ous­ly thought in the catal­y­sis lit­er­a­ture. The nanome­ter sized clus­ters in POMs also pos­sess sur­face species when a sec­ond met­al oxide com­po­nent is intro­duced (e.g., H3+xPW12-xMxO40). Depo­si­tion of met­al oxides into mol­e­c­u­lar sieves, zeo­lites, clays and hydro­tal­cites also results in the met­al oxide addi­tive usu­al­ly being present as sur­face met­al oxide species that are the cat­alyt­ic active sites for many redox and acid reac­tions. The for­ma­tion of these sur­face met­al oxide phas­es is dri­ven by their low sur­face free ener­gy and low Tam­mann tem­per­a­ture for many met­al oxides of inter­est in catal­y­sis (e.g., VOx, MoOx, CrOx, ReOx, WOx, etc.).
 
Biog­ra­phy — Israel E. Wachs received his under­grad­u­ate edu­ca­tion at The City Col­lege of The City Uni­ver­si­ty of New York where he grad­u­at­ed with a B.E. (ChE) in June, 1973. He received sev­er­al recog­ni­tions upon grad­u­a­tion (AIChE Award for Out­stand­ing Senior, Heller Memo­r­i­al Award for Out­stand­ing Scholas­tic Achieve­ment, and White ChE Alum­ni Award). He con­tin­ued his grad­u­ate ChE edu­ca­tion at Stan­ford Uni­ver­si­ty under the men­tor­ship of Pro­fes­sor Robert J. Madix in the area of sur­face sci­ence, and grad­u­at­ed with a PhD (ChE) in 1978. His research find­ings are con­sid­ered the first appli­ca­tion of sur­face sci­ence to catal­y­sis, and his the­sis pub­li­ca­tions are exten­sive­ly cit­ed in the sur­face sci­ence and catal­y­sis lit­er­a­ture.
 
INDUSTRIAL YEARS (1977–1986) — Israel joined Exxon Research & Engi­neer­ing Com­pa­ny in their Cor­po­rate Research Labs towards the end of 1977. At Exxon, he was involved with many dif­fer­ent cat­alyt­ic tech­nolo­gies over the years (selec­tive oxi­da­tion, acid catal­y­sis, syn­the­sis of syn­thet­ic fuels, hydrodesul­fu­r­iza­tion (HDS) and hydro­car­bon con­ver­sion). He obtained 100 USA and inter­na­tion­al patents dur­ing his indus­tri­al career. One of his inven­tions on the selec­tive oxi­da­tion of o-xylene to phthal­ic anhy­dride became the lead­ing inter­na­tion­al indus­tri­al cat­a­lyst for this tech­nol­o­gy and is still used around the world. At Exxon, he received the Research Incen­tive Award for one of his inven­tions on the syn­the­sis of syn­thet­ic fuels and was also select­ed to be an Exxon Fel­low for the spring semes­ter of 1986 at Cal­i­for­nia Insti­tute of Tech­nol­o­gy (Cal­Tech). He depart­ed for acad­e­mia at the end of 1986.
 
ACADEMIC YEARS (1987-present) — He joined the Chem­i­cal Engi­neer­ing Depart­ment of Lehigh Uni­ver­si­ty in Jan­u­ary 1987. At Lehigh, he taught many dif­fer­ent cours­es over the years: Het­ero­ge­neous Catal­y­sis, Reac­tor Engi­neer­ing, Flu­id Mechan­ics, Pro­fes­sion­al Devel­op­ment, Unit Oper­a­tions, Envi­ron­men­tal Catal­y­sis, and Air Pol­lu­tion Con­trol. He set up a world-class catal­y­sis research lab­o­ra­to­ry focus­ing on mixed met­al oxide cat­alyt­ic mate­ri­als and their char­ac­ter­i­za­tion under reac­tion con­di­tions (in situ and operan­do spec­troscopy). These stud­ies have estab­lished the foun­da­tion for the molecular/electronic struc­ture – activity/selectivity rela­tion­ships and the mol­e­c­u­lar engi­neer­ing of mixed met­al oxide cat­a­lysts. The research per­formed by Wachs and his stu­dents is well known around the world. This is reflect­ed in the many nation­al and inter­na­tion­al hon­ors he has received over the years as well as ~17,000 cita­tions to his pub­li­ca­tions with an H-index of 70 (one of the high­est among het­ero­ge­neous catal­y­sis researchers).

The cur­rent focus of Wachs’ catal­y­sis lab­o­ra­to­ry is to devel­op cat­a­lyst char­ac­ter­i­za­tion tech­niques under reac­tion con­di­tions, referred to as operan­do spec­troscopy in the recent lit­er­a­ture. The term operan­do spec­troscopy implies that the cat­a­lyst char­ac­ter­i­za­tion infor­ma­tion is being con­duct­ed simul­ta­ne­ous­ly with online prod­uct analy­sis. Along these lines, Pro­fes­sor Wachs has devel­oped instru­men­ta­tion that can simul­ta­ne­ous­ly obtain Raman, IR and UV-vis spec­tro­scop­ic infor­ma­tion and prod­uct analy­sis with an online mass spectrometer/GC sys­tem. This cut­ting-edge instru­ment is allow­ing Pro­fes­sor Wachs’ catal­y­sis research group to rapid­ly devel­op molecular/electronic struc­ture – cat­alyt­ic activity/selectivity rela­tion­ships for many dif­fer­ent cat­alyt­ic mate­ri­als and reac­tions (selec­tive hydro­car­bon oxi­da­tion, hydro­car­bon con­ver­sion with sol­id acid cat­a­lysts, gas-to-liq­uids, pho­to­cat­alyt­ic split­ting of water, enzyme catal­y­sis, CO2 cap­ture, WGS, nanocatal­y­sis, ratio­nal cat­a­lyst design, etc.).

Water Gas Shift over Industrial Cu Catalysts: A Mechanistic and Microkinetic Investigation

Meetimg Program — September 2012

 
Ros­tam J. Madon
BASF Cor­po­ra­tion
25 Middlesex/Essex Turn­pike
Iselin, NJ, USA 08830
rostam.​madon@​basf.​com
 
Abstract — Low tem­per­a­ture water gas shift (LTS) is a com­mer­cial­ly impor­tant reac­tion that takes place over a Cu-ZnO-Al2O3 cat­a­lyst. A large num­ber of fun­da­men­tal stud­ies have been car­ried out for this reac­tion includ­ing inves­ti­ga­tions of the reac­tion mech­a­nism as typ­i­fied by Refs. [1–4]. In short, dis­cus­sions have cen­tered around (a) the redox mech­a­nism in which adsorbed H2O is dis­so­ci­at­ed to O* and OH* and the O* is removed via CO* to form CO2 – where * is an active site, and (b) for­mate as a reac­tive inter­me­di­ate. Recent­ly, Gokhale et al. [5] using a DFT inves­ti­ga­tion of the LTS reac­tion on Cu(111) pro­posed a new mech­a­nism that involves a reac­tive sur­face car­boxyl. Our study is aimed at resolv­ing which ele­men­tary steps best describe the cat­alyt­ic cycle for the LTS reac­tion. To achieve this, we used the micro­ki­net­ic mod­el­ing method­ol­o­gy pio­neered by Dumesic [6], and ana­lyzed our reac­tiv­i­ty data using all ele­men­tary steps, includ­ing those that described the redox mech­a­nism, the for­mate mech­a­nism, and the car­boxyl mech­a­nism. Thus, we ensured that there was no bias towards any par­tic­u­lar reac­tions to fit our data. We found the closed cat­alyt­ic cycle for LTS on Cu con­sists of eight ele­men­tary steps that include the for­ma­tion of COOH*, and its reac­tion with OH* to form CO2* and H2O*. The cycle does not include the reac­tion of CO2* and H* to form sur­face for­mate. How­ev­er, this is an impor­tant side reac­tion, which ensures sig­nif­i­cant cov­er­age of biden­tate for­mate species on the Cu sur­face. Biden­tate for­mate is a spec­ta­tor species whose cov­er­age increas­es with increas­ing pres­sure and decreas­es with increas­ing tem­per­a­ture. In sum­ma­ry, our inves­ti­ga­tion demon­strates that the redox and for­mate mech­a­nisms are not rel­e­vant, and that the LTS cat­alyt­ic cycle involves the for­ma­tion and reac­tion of sur­face car­boxyl. Sev­er­al relat­ed aspects of the LTS reac­tion on Cu will also be dis­cussed.
 

References

  1. Ovesen, C. V., et al. J. Catal. 158, (1996), 170.
  2. Koryabki­na, N. A. et al. J. Catal. 217, (2003), 233.
  3. Rhodes, C., Hutch­ings G.J., and Ward A.M. Catal. Today 23, (1995), 43.
  4. Her­wi­j­nen, T.V., and de Jong, W. A. J. Catal. 63, (1980), 83 and 94.
  5. Gokhale, A. A., Dumesic, J. A., and Mavrikakis, M. J. Am. Chem. Soc. 130, (2008), 1402.
  6. Dumesic, J. A., et al. “The Micro­ki­net­ics of Het­ero­ge­neous Catal­y­sis”, Amer­i­can Chem­i­cal Soci­ety, Wash­ing­ton, D. C., 1993.

 
Speak­er Bio — Ross com­plet­ed his under­grad­u­ate stud­ies in chem­i­cal engi­neer­ing at the Uni­ver­si­ty Depart­ment of Chem­i­cal Tech­nol­o­gy, Mum­bai, India. He did his grad­u­ate work at Stan­ford Uni­ver­si­ty, obtain­ing his Ph.D. under the guid­ance of Pro­fes­sor Michel Boudart. After com­plet­ing his post-doc­tor­al work with Pro­fes­sor W. Kei­th Hall at the Uni­ver­si­ty of Wis­con­sin — Mil­wau­kee, Ross joined Exxon Research and Engi­neer­ing Com­pa­ny. After 12 years with Exxon’s Cor­po­rate Research Lab­o­ra­to­ries, Ross joined Engel­hard Cor­po­ra­tion. Ross recent­ly com­plet­ed 25 years at Engelhard/BASF Cor­po­ra­tion where he is cur­rent­ly a Senior Research Asso­ciate.

Ross has made pio­neer­ing con­tri­bu­tions to the chem­istry and engi­neer­ing of cat­alyt­ic process­es. Ear­ly in his career with his advi­sor Michel Boudart, he devel­oped an exper­i­men­tal method to address arti­facts in kinet­ic data; a test accept­ed today as being defin­i­tive for kinet­ic con­trol in catal­y­sis. At Exxon, Ross’ stud­ies in Fis­ch­er-Trop­sch syn­the­sis demon­strat­ed the cru­cial role intra­parti­cle dif­fu­sion played in enhanc­ing hydro­car­bon chain length and in chang­ing selec­tiv­i­ty. At Engel­hard, he devel­oped impor­tant con­cepts in flu­id cat­alyt­ic crack­ing to help design com­mer­cial cat­a­lysts. He elu­ci­dat­ed the mech­a­nism by which vana­di­um caus­es struc­tur­al degra­da­tion of Y zeo­lite in FCC cat­a­lysts, and used this under­stand­ing to min­i­mize its dele­te­ri­ous effect. His stud­ies pro­vid­ed a def­i­nite assess­ment of the role of ZSM-5 addi­tives in FCC to form light olefins and high octane gaso­line. And, he defined the crit­i­cal role rare earth cations play in Y-based FCC cat­a­lysts, demon­strat­ing how the pres­ence of rare earth influ­ences hydride trans­fer reac­tions and prod­uct selec­tiv­i­ty in FCC. Most recent­ly, at BASF, Ross, togeth­er with col­leagues in acad­e­mia, elu­ci­dat­ed the mech­a­nism of the water gas shift reac­tion on cop­per, evinc­ing para­me­ters that could sig­nif­i­cant­ly improve cat­alyt­ic activ­i­ty. Impor­tant­ly, though, Ross has used his con­cep­tu­al and mech­a­nis­tic approach to cat­a­lyst research to design com­mer­cial cat­a­lysts. He is the coin­ven­tor and devel­op­er of the Redux­ion – Max­ol® fam­i­ly of FCC cat­a­lysts and of the Iso­Plus® and Ultri­um® fam­i­lies; all of which have been used com­mer­cial­ly world­wide. He coin­vent­ed the Flex-Tec® resid crack­ing cat­a­lyst which has been wide­ly and suc­cess­ful­ly deployed in demand­ing resid cat-crack­ing process­es. And most recent­ly he has devel­oped sev­er­al cop­per based cat­a­lysts for the petro­chem­i­cal indus­try.

Ross chaired the 1996 Gor­don Research Con­fer­ence on Catal­y­sis, and in 2009 was award­ed the AIChE Catal­y­sis and Reac­tion Engi­neer­ing Divi­sion Prac­tice Award.

Commercialisation of a Novel Methyl Methacrylate Process – Catalyst Design and Development

2012 Spring Symposium

 
David W. John­son
Lucite Inter­na­tion­al UK Ltd

Abstract — A brief out­line of Lucite International’s new “Alpha” methyl methacry­late tech­nol­o­gy is described includ­ing process scale up and the first exploita­tion in Sin­ga­pore in late 2008. The tech­nol­o­gy was devel­oped from 0.5g/h lab scale to 500g/h pilot and thence direct­ly to 12te/h com­mer­cial scale. The plant was com­mis­sioned from first intro­duc­tion of chem­i­cals to 100% rate with­in 3 weeks and cur­rent­ly oper­ates at over 16te/h with excep­tion­al reli­a­bil­i­ty.

Two cat­alyt­ic steps are key to the tech­nol­o­gy. In the first, car­bon monox­ide, eth­yl­ene and methanol are react­ed in solu­tion with a nov­el pal­la­di­um phos­phine cat­a­lyst which gives methyl pro­pi­onate in 99.9+% selec­tiv­i­ty in a con­tin­u­ous process at ppm lev­el pal­la­di­um con­cen­tra­tions at 100C and 10bar total pres­sure. The cat­a­lyst activ­i­ty and life is very sen­si­tive to oper­at­ing con­di­tions. After exten­sive process devel­op­ment, activ­i­ties of 15,000 moles/mole Pd/h and life of >1x107moles methyl propionate/mole Pd are rou­tine­ly achieved on the com­mer­cial plant.

The sec­ond stage cat­a­lyst, com­posed of caesium/zirconia/silica reacts methyl pro­pi­onate with formalde­hyde at 330C and 1–2barg to form methyl methacry­late (MMA) and water. The selec­tiv­i­ty is about 93% to MMA based on methyl pro­pi­onate and over 80% on formalde­hyde fed. The pre­sen­ta­tion describes some of the steps in devel­op­ment of the cat­a­lyst includ­ing com­par­isons with cat­a­lysts for sim­i­lar process dis­closed by com­peti­tors. A dis­cus­sion of the mech­a­nism of for­ma­tion of MMA and byprod­ucts is made in terms of sur­face reac­tions between reac­tants and prod­ucts. A 2-site mod­el is pro­posed involv­ing both strong­ly basic and hydrox­ylic, weak­ly acidic sites. Reac­tions catal­ysed in byprod­uct for­ma­tion include decar­boxy­la­tions, com­bined con­den­sa­tion-decar­boxy­la­tions, hydride trans­fers and acid catal­y­sis. Lucite has found that com­pet­i­tive cat­a­lysts have the wrong bal­ance of acid­i­ty and basic­i­ty and result gen­er­al­ly in high lev­els of hydride trans­fer and acid catal­y­sis prod­ucts.

Speaker’s Biog­ra­phy: The author has a BA (Nat­ur­al Sci­ences, Chem­istry) from Oxford Uni­ver­si­ty a PhD in radi­a­tion chem­istry and car­ried out post­doc­tor­al research in LEED/XPS/UPS before join­ing ICI Ltd in 1977. With­in ICI he worked ini­tial­ly on nitrate pro­mot­ed sil­ver eth­yl­ene oxide cat­a­lysts fol­lowed by 4 years in ICI’s New Sci­ence Group study­ing the struc­ture of nov­el zeo­lites syn­the­sised by ICI co-work­ers. Since 1990 he has worked in the area of MMA process design and led the explorato­ry research team which defined the Alpha process and cur­rent­ly leads Lucite’s (for­mer­ly ICI Acrylics) chem­istry team. His cur­rent inter­ests are process improve­ment for the Alpha tech­nol­o­gy and intro­duc­tion of biotech­nol­o­gy into MMA man­u­fac­ture.

Challenges in Catalysis Applied to Pharmaceutical Development

2012 Spring Symposium

 
Alan M. All­geier
DuPont (for­mer­ly Amgen Inc.)

Abstract — In the devel­op­ment of phar­ma­ceu­ti­cals, catal­y­sis plays a crit­i­cal role and its prac­ti­tion­ers must nim­bly assim­i­late knowl­edge of organ­ic chem­istry, sur­face reac­tions, reac­tion engi­neer­ing and prod­uct iso­la­tion. In this pre­sen­ta­tion we explore three themes in catal­y­sis for the phar­ma­ceu­ti­cal indus­try: 1) Enabling New Reac­tiv­i­ty, 2) Qual­i­ty… Above All Else and 3) Speed to Deci­sions… Speed to Mar­ket.

New Reac­tiv­i­ty: Asym­met­ric hydro­formy­la­tion of nor­bornene and uti­liza­tion of keto­lac­tols as alde­hyde sur­ro­gates in reduc­tive ami­na­tion are described as nov­el chemistries demon­strat­ed on clin­i­cal man­u­fac­tur­ing scale. In the lat­ter case, den­si­ty func­tion­al the­o­ry pro­vides insight into the mech­a­nism of the reac­tion.
Qual­i­ty: The use of pre­cious met­al cat­a­lysts engen­ders chal­lenges of remov­ing poten­tial­ly tox­ic met­als to meet qual­i­ty spec­i­fi­ca­tions. The emerg­ing tech­nique of HPLC with ICP/MS detec­tion is a valu­able tool for under­stand­ing the diver­si­ty of resid­ual met­al com­plex­es and iden­ti­fy­ing process options to clear met­al impu­ri­ties. In one such devel­op­ment effort a unique dearom­a­ti­za­tion reac­tion was char­ac­ter­ized and its mech­a­nism elu­ci­dat­ed.

Speed: In con­duct­ing hydro­gena­tion catal­y­sis for phar­ma­ceu­ti­cals cat­a­lyst deac­ti­va­tion is inevitably observed at some stage of devel­op­ment. In one case deac­ti­va­tion was par­tic­u­lar­ly depen­dent upon gas to liq­uid mass trans­fer rates in batch reac­tors. A method for mea­sur­ing the vol­u­met­ric mass trans­fer coef­fi­cient (kLa) is described. Using this infor­ma­tion reduces risk asso­ci­at­ed with scale up from lab­o­ra­to­ry to man­u­fac­tur­ing equip­ment.

Speaker’s Biog­ra­phy — Alan All­geier grew up in the beau­ti­ful coun­try­side of north­west Penn­syl­va­nia. He earned his Ph.D. in Inor­gan­ic Chem­istry in 1997 from North­west­ern Uni­ver­si­ty under the direc­tion of Prof. Chad Mirkin. He com­plet­ed post-doc­tor­al stud­ies in het­ero­ge­neous catal­y­sis at DuPont under Dr. Theodore Koch and con­tin­ued at DuPont work­ing on hydro­gena­tion process­es for nylon monomers and spe­cial­ty chem­i­cals, as well as, homo­ge­neous­ly cat­alyzed olefin hydro­cya­na­tion for spe­cial­ty chem­i­cal appli­ca­tions. In 2004 Dr. All­geier moved to Amgen to estab­lish a com­pe­ten­cy in het­ero­ge­neous catal­y­sis and pres­sure chem­istry in sup­port of drug dis­cov­ery and devel­op­ment. In 2011 he returned to DuPont to lead a lab­o­ra­to­ry in the Sur­face and Par­ti­cle Sci­ence Com­pe­ten­cy. Through his career Dr. All­geier has been a leader in pro­fes­sion­al orga­ni­za­tions includ­ing Arrange­ments Chair, Pro­gram Chair, Trea­sur­er and Chair of the Philadel­phia Catal­y­sis Club, Board mem­ber of the 19th North Amer­i­can Catal­y­sis Soci­ety Meet­ing, and Chair of the Organ­ic Reac­tions Catal­y­sis Soci­ety and its 23rd Con­fer­ence. He is a con­tribut­ing author / inven­tor of six­teen jour­nal arti­cles and four­teen patents or patent appli­ca­tions and served as Guest Edi­tor for Top­ics in Catal­y­sis. His tech­ni­cal inter­ests include cat­alyt­ic reac­tions for hydro­gena­tion, car­bony­la­tion, and cou­pling, as well as, cat­a­lyst deac­ti­va­tion and reac­tor design.

Density Functional Theory Studies of Electrocatalysis

2012 Spring Symposium

 
Michael J. Janik
Depart­ment of Chem­i­cal Engi­neer­ing
Penn­syl­va­nia State Uni­ver­si­ty

Abstract — Den­si­ty func­tion­al the­o­ry (DFT) meth­ods are wide­ly used to eval­u­ate sur­face cat­alyt­ic reac­tion mech­a­nisms and to pre­dict the rel­a­tive per­for­mance of var­i­ous cat­a­lyst for­mu­la­tions or struc­tures. The use of mod­el sys­tems, such as the sin­gle-crys­tal sur­face, to exam­ine cat­alyt­ic prop­er­ties is well-estab­lished, with the gaps between mod­el sys­tems and real­is­tic sup­port­ed cat­a­lysts rel­a­tive­ly under­stood. Trans­la­tion of DFT approach­es to the elec­tro­cat­alyt­ic envi­ron­ment requires addi­tion­al method­olog­i­cal choic­es due to addi­tion­al com­plex­i­ties offered by the elec­tri­fied cat­a­lyst-elec­trolyte inter­face. This talk will pro­vide an overview of these chal­lenges and the var­i­ous DFT approach­es used to mod­el elec­tro­cat­alyt­ic sys­tems. The use of DFT to deter­mine elec­tro­cat­alyt­ic reac­tion mech­a­nisms and guide the design of cat­alyt­ic mate­ri­als will be dis­cussed using exam­ples from our group’s research; boro­hy­dride oxi­da­tion, oxy­gen reduc­tion, and car­bon diox­ide reduc­tion.

Speaker’s Biog­ra­phy — Dr. Janik is an assis­tant pro­fes­sor of Chem­i­cal Engi­neer­ing at PSU, begin­ning his appoint­ment August, 2006. His research inter­ests are in the use of com­pu­ta­tion­al meth­ods to under­stand and design mate­ri­als for alter­na­tive ener­gy con­ver­sion sys­tems. Cur­rent activ­i­ties address a wide-range of ener­gy tech­nolo­gies includ­ing fuel cells and bat­ter­ies, hydro­gen gen­er­a­tion, desul­fu­r­iza­tion, and CO2 cap­ture. Research meth­ods empha­size atom­istic sim­u­la­tion using quan­tum chem­i­cal meth­ods and kinet­ic mod­el­ing. Janik is affil­i­at­ed with the PSU Elec­tro­chem­i­cal Engine Cen­ter, Bat­tery and Ener­gy Stor­age Tech­nol­o­gy Cen­ter and the PSU Insti­tutes of Ener­gy and the Envi­ron­ment. Janik is the direc­tor of a Nation­al Sci­ence Foun­da­tion sup­port­ed Research Expe­ri­ence for Under­grad­u­ates cite in “Chem­i­cal Ener­gy Stor­age and Con­ver­sion.” The Janik research group cur­rent­ly includes 8 grad­u­ate stu­dents and 11 under­grad­u­ate stu­dents. Dr. Janik received his B. S. in Chem­i­cal Engi­neer­ing from Yale Uni­ver­si­ty. Fol­low­ing three years as a Process Engi­neer for Proc­ter and Gam­ble, Janik com­plet­ed his doc­tor­al stud­ies at the Uni­ver­si­ty of Vir­ginia. Janik com­plet­ed his doc­tor­al the­sis in 2006 exam­in­ing acid catal­y­sis by poly­ox­omet­a­lates fol­lowed by post-doc­tor­al work study­ing methanol elec­troox­i­da­tion. He is the author of approx­i­mate­ly 50 peer reviewed papers.

Desktop Molecular Modeling Help in Clarifying Odd Experimental Observations on Zeolites and Silica Gels

2012 Spring Symposium

 
Ist­van Halasz
PQ Cor­po­ra­tion

Abstract — Zeo­lites and amor­phous sil­i­ca gels are wide­ly used in adsorp­tion and catal­y­sis. PQ com­mer­cial­izes sil­i­ca based mate­ri­als by tai­lor­ing them to spe­cif­ic cus­tomer needs world­wide. These mod­i­fi­ca­tions usu­al­ly require series of mate­r­i­al tests which most­ly car­ried out at the company’s R&D Cen­ter where I have been assigned to inves­ti­gate the poros­i­ty, acid­i­ty, sorp­tion capac­i­ty, activ­i­ty and oth­er tar­get­ed prop­er­ties of exper­i­men­tal and com­mer­cial prod­ucts. Some­times these exper­i­ments lead to unex­pect­ed, sur­pris­ing, con­tra­dic­to­ry results which usu­al­ly gen­er­ate var­i­ous spec­u­la­tive expla­na­tions. In this pre­sen­ta­tion I’ll illus­trate through a few exam­ples how mol­e­c­u­lar mod­el­ing can help in resolv­ing con­flicts between ideas and empir­i­cal find­ings. I intend to show that the com­mon­ly avail­able com­put­er pow­er and mod­el­ing pro­grams have devel­oped so much dur­ing the past few years that even an exper­i­men­tal­ist with lim­it­ed resources and the­o­ret­i­cal back­ground can mim­ic var­i­ous empir­i­cal data which is the basis to under­stand­ing mate­r­i­al prop­er­ties at the mol­e­c­u­lar lev­el. It will be also shown how com­put­er chem­istry can lead to improved quan­tifi­ca­tion of oth­er­wise rou­tine­ly mea­sured mol­e­c­u­lar spec­tro­scop­ic data. The pre­sent­ed exam­ples will include mod­el cal­cu­la­tions based on force field relat­ed Monte Car­lo algo­rithm, time depen­dent den­si­ty func­tion­al the­o­ry, and a com­bi­na­tion of quan­tum mechanical/molecular mechan­i­cal meth­ods. Sim­u­lat­ed exper­i­men­tal sorp­tion isotherms and FTUV spec­tra of two hydropho­bic zeo­lites will be pre­sent­ed to explain their unusu­al sorp­tion prop­er­ties and redox cat­alyt­ic activ­i­ties. More­over, we com­pare the mod­el and exper­i­men­tal FTIR and laser Raman spec­tra of some amor­phous sil­i­cates and present the first exper­i­men­tal proof that sil­i­ca gels obtained from aque­ous alka­line sil­i­cate solu­tions or tetra-eth­yl-orthosil­i­cate at acidic or basic con­di­tions can have dis­tinct mol­e­c­u­lar struc­tures which affect their final phys­i­cal prop­er­ties.

Speaker’s Biog­ra­phy — Ist­van obtained a physics and chem­istry teacher diplo­ma from the Lajos Kos­suth Uni­ver­si­ty, Hun­gary. Lat­er he was award­ed magna cum laude doc­tor­ate degree from the same uni­ver­si­ty and a high­er degree from the Hun­gar­i­an Acad­e­my of Sci­ences, HAS. Fol­low­ing three years of teach­ing phys­i­cal chem­istry, he joined the Hun­gar­i­an Hydro­car­bon Insti­tute, where he devel­oped new, eco­nom­ic process­es for phar­ma­ceu­ti­cal, fine chem­i­cal and petro­chem­i­cal plants and stud­ied the fun­da­men­tals of acid-base catal­y­sis over met­al oxides. As a young sci­en­tist he won sev­er­al com­pet­i­tive awards and a research schol­ar­ship for the Uni­ver­si­ty of Tech­nol­o­gy in Vien­na, Aus­tria. After 12 years of indus­tri­al research, he moved to the Chem­i­cal Research Insti­tute of HAS where his major research top­ics includ­ed shape selec­tive catal­y­sis on zeo­lites and syn­the­sis of high tem­per­a­ture ceram­ic super­con­duc­tors. Ist­van also worked as post­doc­tor­al researcher at Wayne State Uni­ver­si­ty and Uni­ver­si­ty of Iowa, focus­ing main­ly on the cat­alyt­ic abate­ment of auto­mo­bile exhausts and indus­tri­al stack gas­es. He joined PQ near­ly 14 years ago. He has been mem­ber of sev­er­al sci­en­tif­ic orga­ni­za­tions and cur­rent­ly serves as pres­i­dent of NECZA (North East Cor­ri­dor Zeo­lite Asso­ci­a­tion). Ist­van has authored and co-authored more than 180 pub­li­ca­tions.