2013 Spring Symposium

 
Andrew M. Rappe
Pen­ner­gy Co-Direc­tor
Depart­ment of Chem­istry
Uni­ver­si­ty of Penn­syl­va­nia
Philadel­phia, PA 19104
rappe@​sas.​upenn.​edu
 
Abstract — The quest to design sur­faces with use­ful cat­alyt­ic activ­i­ty has received a dra­mat­ic boost from mod­ern tech­niques of oxide epi­tax­i­al growth and char­ac­ter­i­za­tion. This unprece­dent­ed exper­i­men­tal con­trol of oxide sur­faces opens great oppor­tu­ni­ties to design new cat­a­lysts using the­o­ry and mod­el­ing. In this talk, I will describe a vari­ety of new approach­es for tai­lor­ing sur­face prop­er­ties by con­trol­ling oxide com­po­si­tion and struc­ture, before focus­ing on two spe­cif­ic exam­ples. 1. Polar oxides show struc­tur­al defor­ma­tions that change the struc­ture and com­po­si­tion of sur­faces. 2. Anneal­ing com­plex oxides can lead to sur­face recon­struc­tions with com­po­si­tions dif­fer­ent from any bulk mate­r­i­al. These tech­niques lead to sur­faces with under­co­or­di­nat­ed tran­si­tion met­al cations that should offer nov­el reac­tiv­i­ty.
 

Biog­ra­phy — Andrew M. Rappe is a Pro­fes­sor of Chem­istry and Pro­fes­sor of Mate­ri­als Sci­ence and Engi­neer­ing at the Uni­ver­si­ty of Penn­syl­va­nia. He received his A. B. in “Chem­istry and Physics” sum­ma cum laude from Har­vard Uni­ver­si­ty in 1986, and his Ph. D. in “Physics and Chem­istry” from MIT in 1992. He was an IBM Post­doc­tor­al Fel­low at UC Berke­ley before start­ing at Penn in 1994.

Andrew received an NSF CAREER award in 1997, an Alfred P. Sloan Research Fel­low­ship in 1998, and a Camille Drey­fus Teacher-Schol­ar Award in 1999. He was named a Fel­low of the Amer­i­can Phys­i­cal Soci­ety in 2006.

Andrew is one of the two found­ing co-direc­tors of Pen­ner­gy: the Penn Cen­ter for Ener­gy Inno­va­tion. He is also one of the found­ing co-direc­tors of the VIPER hon­ors pro­gram at Penn, the Vage­los Inte­grat­ed Pro­gram in Ener­gy Research.

His cur­rent research inter­ests revolve around fer­ro­elec­tric phase tran­si­tions in oxides, sur­face chem­istry and catal­y­sis of com­plex oxides, and the inter­play between the two: a) He helped estab­lish rela­tion­ships between com­po­si­tion and fer­ro­elec­tric phase tran­si­tion tem­per­a­ture in bis­muth-con­tain­ing per­ovskites oxides, b) He pre­dict­ed that chang­ing chem­i­cal vapor com­po­si­tion above a fer­ro­elec­tric oxide could reori­ent its polar­iza­tion, c) He revealed the mech­a­nism of domain wall motion in fer­ro­elec­tric oxides, d) He showed that chang­ing fer­ro­elec­tric polar­iza­tion dra­mat­i­cal­ly changes cat­alyt­ic activ­i­ty of sup­port­ed met­al films and nanopar­ti­cles, and e) He uses com­pu­ta­tion­al mate­ri­als design to invent new fer­ro­elec­tric pho­to­voltaics for solar appli­ca­tions.

2013 Spring Symposium

 
Michael T. Klein
Direc­tor, Uni­ver­si­ty of Delaware Ener­gy Insti­tute
Dan Rich Chair of Ener­gy
Depart­ment of Chem­i­cal Engi­neer­ing
Uni­ver­si­ty of Delaware
Newark, DE 19716
mtk@​udel.​edu
 
Abstract — The world-wide ener­gy trans­porta­tion sec­tor is almost entire­ly depen­dent on petro­le­um, a remark­able resource on which a high­ly sophis­ti­cat­ed refin­ing and vehi­cle infra­struc­ture has grown. Giv­en the cap­i­tal val­ue of the exist­ing world-wide refin­ing and trans­porta­tion infra­struc­tures, and the decadal char­ac­ter­is­tic time for their change, it is like­ly that car­bon-based resources, includ­ing uncon­ven­tion­al feed­stocks that will be upgrad­ed for use with petro­le­um in the exist­ing infra­struc­ture, will be uti­lized for decades to come. Math­e­mat­i­cal mod­els of the chem­istry of their upgrad­ing and con­ver­sion will assist the com­mer­cial real­iza­tion of these pos­si­bil­i­ties.

The con­sid­er­able inter­est in mol­e­cule-based mod­els of these chemistries is moti­vat­ed by the need to pre­dict both upstream and down­stream prop­er­ties. This is because the mol­e­c­u­lar com­po­si­tion is an opti­mal start­ing point for the pre­dic­tion of mix­ture prop­er­ties. The chal­lenge of build­ing these mod­els is due to the stag­ger­ing com­plex­i­ty of the com­plex reac­tion mix­tures. There will often be thou­sands of poten­tial mol­e­c­u­lar and inter­me­di­ate (e.g., ions or rad­i­cals) species. Clear­ly, the use of the com­put­er to not only solve but also for­mu­late the mod­el would be help­ful in that it would allow the mod­el­er to focus on the basic chem­istry, physics and approx­i­ma­tions of the mod­el.

Our recent work has led to the devel­op­ment of an auto­mat­ed capa­bil­i­ty to mod­el devel­op­ment. Sta­tis­ti­cal sim­u­la­tion of feed­stock struc­ture casts the mod­el­ing prob­lem in mol­e­c­u­lar terms. Reac­tiv­i­ty infor­ma­tion is then orga­nized in terms of quan­ti­ta­tive lin­ear free ener­gy rela­tion­ships. The mod­el equa­tions are then built and cod­ed on the com­put­er. Solu­tion of this chem­i­cal reac­tion net­work, in the con­text of the chem­i­cal reac­tor, pro­vides a pre­dic­tion of the mol­e­c­u­lar com­po­si­tion, which is then orga­nized into any desired com­mer­cial­ly rel­e­vant out­puts. Of par­tic­u­lar note is the Attribute Reac­tion Mod­el approach that is use­ful when the num­ber of desired com­po­nents in the mol­e­c­u­lar mix­ture is con­strained by the prac­ti­cal lim­its of hard­ware and soft­ware.

Biog­ra­phy — Michael T. Klein start­ed his career at the Uni­ver­si­ty of Delaware, where he served as the Eliz­a­beth Inez Kel­ley Pro­fes­sor of Chem­i­cal Engi­neer­ing as well as Depart­ment Chair, Direc­tor of the Cen­ter for Cat­alyt­ic Sci­ence and Tech­nol­o­gy, and Asso­ciate Dean. He then moved to Rut­gers, The State Uni­ver­si­ty of New Jer­sey, to become the Dean of Engi­neer­ing and the Board of Gov­er­nors Pro­fes­sor of Chem­i­cal Engi­neer­ing. On July 1, 2010, he returned to the Uni­ver­si­ty of Delaware to assume his present posi­tion as the Direc­tor of the Uni­ver­si­ty of Delaware Ener­gy Insti­tute and the Dan Rich Chair of Ener­gy.

Pro­fes­sor Klein received a BChE from the Uni­ver­si­ty of Delaware in 1977 and a Sc. D. from MIT in 1981, both in Chem­i­cal Engi­neer­ing. The author of over 200 tech­ni­cal papers and the lead author of the text Mol­e­c­u­lar Mod­el­ing in Heavy Hydro­car­bon Con­ver­sions, he is active in research in the area of chem­i­cal reac­tion engi­neer­ing, with spe­cial empha­sis on the kinet­ics of com­plex sys­tems. He is the Edi­tor-in-Chief of the ACS jour­nal Ener­gy and Fuels and has received the R. H. Wil­helm Award in Chem­i­cal Reac­tion Engi­neer­ing from the AIChE, the NSF PYI Award and the ACS Delaware Val­ley Sec­tion Award. In 2011 Pro­fes­sor Klein was ele­vat­ed to the lev­el of Fel­low of the ACS.

2013 Spring Symposium

2012 Ciapetta Award Lecture

 
Thomas F. Deg­nan, Jr.
Exxon­Mo­bil Research and Engi­neer­ing Com­pa­ny
Annan­dale, NJ 08801
thomas.​f.​degnan@​exxonmobil.​com
 
Abstract — MCM-22 (MTW) is among a unique class of mul­ti­di­men­sion­al pore shape selec­tive zeo­lites where­in the prin­ci­pal locus for catal­y­sis is in 12 mem­ber ring (12-MR) sur­face pock­ets. The zeo­lite con­tains two inde­pen­dent pore sys­tems, both of which are accessed through rings com­prised of ten tetra­he­dral (T) atoms (such as Si, Al, and B). One of these pore sys­tems is defined by two-dimen­sion­al, sinu­soidal chan­nels and the oth­er is defined by large 12-MR supercages with an inner free diam­e­ter of 0.71 nm and a height of 1.82 nm. Vir­tu­al­ly all acid cat­alyzed reac­tions take place in pock­ets formed from the sur­face ter­mi­na­tion of the 1.82 nm high and 0.71 nm diam­e­ter supercages. The zeo­lite has been eval­u­at­ed and found promis­ing for a num­ber of acid-cat­alyzed reac­tions. Most impor­tant­ly, it has been found to be unusu­al­ly selec­tive for aro­mat­ic alky­la­tion in the pres­ence of a wide range of olefins under liq­uid phase con­di­tions. This pre­sen­ta­tion will describe the dis­cov­ery, devel­op­ment and com­mer­cial deploy­ment of this zeo­lite that is used wide­ly in sev­er­al aro­mat­ic alky­la­tion process­es.
 

Biog­ra­phy — Tom received his B.S. in chem­i­cal engi­neer­ing from the Uni­ver­si­ty of Notre Dame, a Ph.D. in the same dis­ci­pline from the Uni­ver­si­ty of Delaware, and an M.B.A. in Finance from the Uni­ver­si­ty of Min­neso­ta. He spent four years in 3M’s Cen­tral Research orga­ni­za­tion in St. Paul, MN before mov­ing to Mobil Research and Devel­op­ment in 1980.

Tom has spent most of his career in explorato­ry process devel­op­ment, catal­y­sis, cat­a­lyst devel­op­ment, and research man­age­ment work­ing for Mobil and now Exxon­Mo­bil Research and Engi­neer­ing Com­pa­ny. He is present­ly Man­ag­er, New Leads Gen­er­a­tion and Break­through Tech­nolo­gies and is locat­ed at ExxonMobil’s Clin­ton, NJ facil­i­ty.

He is a mem­ber of the North Amer­i­can Catal­y­sis Soci­ety, the Amer­i­can Insti­tute of Chem­i­cal Engi­neers, the Amer­i­can Chem­i­cal Soci­ety and the Research and Devel­op­ment Coun­cil of New Jer­sey.

2013 Spring Symposium

CCP Stu­dent Poster Com­pe­ti­tion Win­ner

 
Thomas R. Gor­don
Depart­ment of Chem­istry
Uni­ver­si­ty of Penn­syl­va­nia
Philadel­phia, PA 19104
thomasrgordon@​gmail.​com
 
Abstract — Con­trol over faceting in nanocrys­tals (NCs) is piv­otal for many appli­ca­tions, but most notably when inves­ti­gat­ing cat­alyt­ic reac­tions which occur on the sur­faces of nanos­truc­tures. Tita­ni­um diox­ide (TiO₂) is one of the most stud­ied pho­to­cat­a­lysts, but the depen­dence of its activ­i­ty on mor­phol­o­gy and phase has not yet been sat­is­fac­to­ri­ly inves­ti­gat­ed, due to a lack of appro­pri­ate mod­els. We report the non­aque­ous sur­fac­tant-assist­ed syn­the­sis of high­ly uni­form TiO2 NCs with tai­lorable mor­phol­o­gy in the 1–100 nm size régime. Meth­ods are described to engi­neer the per­cent­age of {001} and {101} facets in anatase and to con­trol the mor­phol­o­gy and phase of TiO₂ nanorods. The sur­fac­tants on the sur­face of the NCs, which direct growth of uni­form par­ti­cles, may be removed through a sim­ple lig­and exchange pro­ce­dure, allow­ing for the shape depen­dence of pho­to­cat­alyt­ic hydro­gen evo­lu­tion to be stud­ied using monodis­perse TiO₂ NCs pre­pared with­out any high tem­per­a­ture anneal­ing. Such high­ly uni­form nanocrys­tals may act as mod­el sys­tems to inves­ti­gate the influ­ence of faceting on a vari­ety of process­es under oper­at­ing con­di­tions.
 

Biog­ra­phy — Dr. Thomas R. Gor­don recent­ly earned his Ph.D in Phys­i­cal Chem­istry from the Uni­ver­si­ty of Penn­syl­va­nia, under the direc­tion of Prof. Christo­pher B. Mur­ray, after defend­ing his the­sis in Feb­ru­ary 2013, enti­tled “Direct­ed Syn­the­sis and Dop­ing of Wide Bandgap Semi­con­duct­ing Oxides.” He received a B.S. in Chem­istry with a minor in Math­e­mat­ics (sum­ma cum laude) from Lebanon Val­ley Col­lege. Dr. Gor­don is the 2006 recip­i­ent of the Dr. Judith Bond Endowed schol­ar­ship win­ner award­ed to out­stand­ing chem­istry major attend­ing a col­lege or uni­ver­si­ty in south­east­ern Penn­syl­va­nia. His research inter­ests include the pre­cise syn­the­sis of nanocrys­talline mate­ri­als and their appli­ca­tions in catal­y­sis, pho­to­catal­y­sis, and plas­mon­ics. In June 2013, he will begin work as a post­doc­tor­al fel­low in the lab­o­ra­to­ry of Prof. Ray­mond Schaak at Penn­syl­va­nia State Uni­ver­si­ty as a mem­ber of the Mate­ri­als Research Sci­ence and Engi­neer­ing Cen­ter (MRSEC). He is the author or co-author of 9 sci­en­tif­ic pub­li­ca­tions.

2013 Spring Symposium

 
Michael A. Smith
Depart­ment of Chem­i­cal Engi­neer­ing
Vil­lano­va Uni­ver­si­ty
Vil­lano­va, PA 19085
michael.​a.​smith@​villanova.​edu
 
Abstract — SBA-15 is a tem­plate-syn­the­sized meso­porous sil­i­cate that has found exten­sive use as a mod­el sup­port for stud­ies of sup­port­ed catalysis.[1, 2] Thor­ough struc­tur­al analy­ses clear­ly describe the dual micro­p­ore-meso­pore struc­ture with a broad dis­tri­b­u­tion of micro­p­ore sizes.[3] Sil­i­cas such as SBA-15 have long been con­sid­ered a rel­a­tive­ly inert sup­port, quite in con­trast to oth­er oxides such as tita­nia or ceria. We find the effect of sur­face rough­ness of SBA-15 has an under­ap­pre­ci­at­ed effect on cat­a­lyst per­for­mance. Specif­i­cal­ly, sam­ples of VO_x-SBA-15 where the sup­port sur­face rough­ness was sys­tem­at­i­cal­ly var­ied were chara­ter­ized using UV-Vis and Raman spec­troscopy, then test­ed in the cat­alyt­ic par­tial oxi­da­tion of methanol to formalde­hyde, and propane to propene. Results show that sup­ports with smoother sur­faces per­mit the devel­op­ment of more poly­mer­ic vana­dia species at the same sur­face den­si­ty load­ing. Such smoother-sur­face cat­a­lysts result in a low­er selec­tiv­i­ty of methanol to for­made­hyde, yet con­verse­ly show a high­er selec­tiv­i­ty of propane to propene. This result is sig­nif­i­cant with respect to our under­stand­ing the role of vana­di­um in in par­tial oxi­da­tion cat­a­lysts, and illus­trates the impor­tance of con­sid­er­ing dif­fer­ences in sup­port sur­face mor­phol­o­gy in ana­lyz­ing cat­alyt­ic behav­ior.
 
Ref­er­ences
[1] V. Dufaud, M. E. Davis, J. Am. Chem. Soc. 125 (2003) 9403–9413.
[2] R. K. Zei­dan, S. J. Hwang, M. E. Davis, Angew. Chem.-Int. Edit. 45 (2006) 6332–6335.
[3] M. Kruk, M. Jaroniec, R. Ryoo, J. M. Kim, Chem. Mat. 11 (1999) 2568–2572.
 

Biog­ra­phy — Pro­fes­sor Michael A. Smith is cur­rent­ly an Assis­tant Pro­fes­sor in the Depart­ment of Chem­i­cal Engi­neer­ing at Vil­lano­va Uni­ver­si­ty. He received his BS in Chem­i­cal Engi­neer­ing from Lafayette Col­lege in 1980, then worked in a vari­ety of assign­ments with the DuPont Com­pa­ny for 17 years. Dr. Smith returned to school to obtain a Mas­ters at Vil­lano­va Uni­ver­si­ty, and obtained his PhD in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Delaware in 2004 work­ing with Prof Raul Lobo. Since he has work as a research sci­en­tist for an SBIR start­up, and has been at Vil­lano­va since 2006, first as a Vis­it­ing Assis­tant Pro­fes­sor, then in a tenure track posi­tion since 2008. Dr Smith’s research inter­ests include the syn­the­sis and char­ac­ter­i­za­tion of nanos­truc­tured mate­ri­als made using col­loidal self-assem­bly and sol-gel tech­niques, and het­ero­ge­neous catal­y­sis with an empha­sis on catal­y­sis by met­al oxides.

2013 Spring Symposium

 
Jef­frey Gree­ley
Depart­ment of Chem­i­cal Engi­neer­ing
Pur­due Uni­ver­si­ty
West Lafayette, IN 47907
jgreeley@​purdue.​edu
 
Abstract — Het­ero­ge­neous catal­y­sis and elec­tro­catal­y­sis have, in recent years, con­tributed sig­nif­i­cant­ly to the devel­op­ment of renew­able and ener­gy-effi­cient tech­nolo­gies, rang­ing from the pro­duc­tion of biore­new­able fuels to the effi­cient gen­er­a­tion of elec­tric­i­ty in fuel cells. Com­pu­ta­tion­al tech­niques, based pri­mar­i­ly on Den­si­ty Func­tion­al The­o­ry (DFT) cal­cu­la­tions, have, at the same time, played an increas­ing­ly impor­tant role in sci­en­tif­ic and engi­neer­ing stud­ies of these cat­alyt­ic process­es. These tech­niques have per­mit­ted the elu­ci­da­tion of fun­da­men­tal cat­alyt­ic reac­tion mech­a­nisms and, in some cas­es, have con­tributed to the com­pu­ta­tion­al design of new cat­a­lysts.

In this talk, I will describe some recent devel­op­ments in the use of DFT-based analy­ses to describe trends in the sci­ence and engi­neer­ing of inter­fa­cial catal­y­sis. Draw­ing on exam­ples in both het­ero­ge­neous catal­y­sis and elec­tro­catal­y­sis, I will out­line some sim­ple strate­gies for com­pu­ta­tion­al analy­sis of com­plex cat­alyt­ic reac­tion net­works and will show how, by tak­ing advan­tage of fun­da­men­tal cor­re­la­tions between the ther­mo­dy­nam­ics and kinet­ics of the rel­e­vant react­ing species, it is often pos­si­ble to describe reac­tiv­i­ty trends in terms of sim­ple vol­cano plots. I will demon­strate the appli­ca­tion of these trends-based analy­ses to tra­di­tion­al con­cepts of cat­alyt­ic activ­i­ty and will fur­ther illus­trate how impor­tant ques­tions of cat­a­lyst selec­tiv­i­ty and elec­tro­chem­i­cal cor­ro­sion may fur­ther be addressed. Next, I will describe how it is now becom­ing pos­si­ble, using nov­el exten­sions of bond order con­ser­va­tion the­o­ries, to under­stand and describe trends in com­plex bio­cat­alyt­ic reac­tion net­works that have pre­vi­ous­ly been beyond the reach of elec­tron­ic struc­ture cal­cu­la­tions. I will close with a dis­cus­sion of a nov­el het­ero­ge­neous cat­alyt­ic and elec­tro­cat­alyt­ic mate­ri­als, includ­ing bifunc­tion­al mate­ri­als, to which these tech­niques may be applied in the future.
 

Biog­ra­phy — Dr. Jef­frey Gree­ley obtained his PhD from the Uni­ver­si­ty of Wis­con­sin-Madi­son in 2004. He then postdoc’d with Jens Nørskov at the Tech­ni­cal Uni­ver­si­ty of Den­mark and devel­oped meth­ods to rapid­ly screen tran­si­tion met­al alloys for promis­ing cat­alyt­ic prop­er­ties. From 2007 to 2013, he was a staff sci­en­tist at Argonne’s Cen­ter for Nanoscale Mate­ri­als where he devel­oped a research pro­gram in com­pu­ta­tion­al nanocatal­y­sis and elec­tro­chem­istry. In 2013, he joined the Depart­ment of Chem­i­cal Engi­neer­ing at Pur­due Uni­ver­si­ty as an asso­ciate pro­fes­sor.