Aditya Bhan
Depart­ment of Chem­i­cal Engi­neer­ing and Mate­ri­als Sci­ence
Uni­ver­si­ty of Min­neso­ta
Twin Cities
 
Abstract — Zeo­lites are crys­talline inor­gan­ic frame­work oxides with chan­nel and pock­et dimen­sions typ­i­cal­ly small­er than 1 nanome­ter. Their con­strained envi­ron­ments are well known to select for chem­i­cal reac­tions via steric mech­a­nisms, typ­i­cal­ly, by exclu­sion of mol­e­cules or tran­si­tion states based on size. The strong effects of pore size and shape as they become com­men­su­rate with those of reac­tant species and the con­comi­tant effects on the enthalpy and entropy of adsorp­tion have also been broad­ly and con­vinc­ing­ly not­ed. We inquire instead, what are the effects of con­fine­ment in small chan­nels?

In this talk, I will present three exam­ples where reac­tiv­i­ty in small 8-mem­bered ring pock­ets of H-MOR dif­fers from that in larg­er 12-mem­bered ring chan­nels of MOR.

(i) We show that the appar­ent effects of pro­ton den­si­ty and of hydrox­yl group envi­ron­ment on DME car­bony­la­tion turnover rates reflect instead the remark­able speci­fici­ty of eight-mem­bered ring zeo­lite chan­nels in accel­er­at­ing kinet­i­cal­ly rel­e­vant *CH3-CO reac­tion steps.

(ii) In zeo­lite pores large enough to accom­mo­date ethanol dimers, ethanol pref­er­en­tial­ly dehy­drates via a bimol­e­c­u­lar path­way to gen­er­ate diethyl ether since the for­ma­tion of ethanol dimer­ic species is ener­get­i­cal­ly more favor­able than the for­ma­tion of ethanol monomers. In zeo­lite chan­nels too small to accom­mo­date ethanol dimers, ethanol is selec­tive­ly dehy­drat­ed via a uni­mol­e­c­u­lar reac­tion path­way to gen­er­ate eth­yl­ene.

(iii) For iso­mer­iza­tion reac­tions of n-hexa­ne, 8-MR chan­nels of H-MOR min­i­mize the free ener­gy of required car­bo­ca­tion­ic tran­si­tion states, pos­si­bly via par­tial con­fine­ment effects that increase the entropy of the tran­si­tion state at the expense of the reac­tion enthalpy.

These find­ings show that con­fine­ment in zeo­lite chan­nels influ­ences rate and selec­tiv­i­ty of hydro­car­bon reac­tions more fun­da­men­tal­ly than sim­ple con­sid­er­a­tions of size and shape.
 
Speaker’s Biog­ra­phy — Aditya Bhan received his Bach­e­lor of Tech­nol­o­gy (B. Tech.) in Chem­i­cal Engi­neer­ing from IIT Kan­pur in 2000. Sub­se­quent­ly, he moved to West Lafayette, Indi­ana and joined the group of Nick Del­gass at Pur­due, where he devel­oped micro­ki­net­ic mod­els to describe propane arom­a­ti­za­tion on pro­ton- and gal­li­um- form ZSM-5 mate­ri­als for his PhD. In 2005, he moved to the Uni­ver­si­ty of Cal­i­for­nia at Berke­ley to pur­sue post-doc­tor­al stud­ies in Pro­fes­sor Enrique Iglesia’s group to study the kinet­ics, mech­a­nism, and site require­ments of dimethyl ether car­bony­la­tion. In Sep­tem­ber 2007, Dr. Bhan took up his present posi­tion as an Assis­tant Pro­fes­sor in the Depart­ment of Chem­i­cal Engi­neer­ing and Mate­ri­als Sci­ence at the Uni­ver­si­ty of Min­neso­ta. Dr. Bhan leads a research group that focus­es on the struc­tur­al and mech­a­nis­tic char­ac­ter­i­za­tion of inor­gan­ic mol­e­c­u­lar sieve cat­a­lysts use­ful in ener­gy con­ver­sion and petro­chem­i­cal syn­the­sis. His research at Min­neso­ta has been rec­og­nized with the McK­night Land Grant Pro­fes­sor and 3M Non-tenured Fac­ul­ty awards.

2010 Spring Symposium

 
Mark A. Sny­der
P.C. Rossin Assis­tant Pro­fes­sor
Depart­ment of Chem­i­cal Engi­neer­ing
Lehigh Uni­ver­si­ty
Beth­le­hem, PA 18015

Abstract — Despite the promise for deriv­ing liq­uid hydro­car­bon fuels and high-val­ue chem­i­cals from renew­able cel­lu­losic feed­stocks, var­i­ous tech­no­log­i­cal chal­lenges have sti­fled the rapid com­mer­cial­iza­tion of the inte­grat­ed biore­fin­ery. The effi­cient and selec­tive down­stream pro­cess­ing of cel­lu­lose deriv­a­tives (e.g., hex­ose, fruc­tose, glu­cose, etc.) exists as a for­mi­da­ble pro­cess­ing bot­tle­neck. Owing to prop­er­ties such as breadth of oper­at­ing con­di­tions, des­ignable chem­i­cal selec­tiv­i­ty, and recy­cla­bil­i­ty, het­ero­ge­neous cat­alyt­ic routes serve as an attrac­tive means, in lieu of bio­log­i­cal, ther­mo­chem­i­cal, and homo­ge­neous ones, for effi­cient hydrother­mal pro­cess­ing of sug­ary cel­lu­lose deriv­a­tives. Yet, hydrother­mal insta­bil­i­ty of cur­rent cat­alyt­ic sup­ports opens excit­ing oppor­tu­ni­ties for the devel­op­ment of next-gen­er­a­tion cat­a­lysts capa­ble of meet­ing selec­tiv­i­ty, effi­cien­cy, and sta­bil­i­ty needs of the future biore­fin­ery.

This talk will high­light efforts to real­ize hydrother­mal­ly sta­ble inor­gan­ic mate­ri­als bear­ing mul­ti­scale, three-dimen­sion­al­ly ordered pore topol­o­gy and tun­able sur­face func­tion­al­i­ty. Specif­i­cal­ly, it will focus on a hier­ar­chi­cal nan­otem­plat­ing approach in which pre-formed inor­gan­ic nanopar­ti­cles are assem­bled into ordered col­loidal crys­tal struc­tures and employed as hard, sac­ri­fi­cial tem­plates for both direct and indi­rect repli­ca for­ma­tion of var­i­ous hydrother­mal­ly sta­ble porous mate­ri­als (e.g., car­bon, tita­nia, zeo­lite). The work is pred­i­cat­ed upon the hypoth­e­sis that hard inor­gan­ic tem­plates help resist pore col­lapse dur­ing struc­tur­al coars­en­ing or con­fined growth of inor­gan­ic repli­ca mate­ri­als, and that decou­pling tem­plate for­ma­tion and repli­ca­tion allows for pre­cise and ver­sa­tile engi­neer­ing of the tem­plate, and thus the repli­ca pore topol­o­gy.

This talk will focus on var­i­ous stages of hier­ar­chi­cal mate­ri­als assem­bly, begin­ning with tech­niques for con­trolled syn­the­sis of pri­ma­ry inor­gan­ic nanopar­ti­cle build­ing units with nanome­ter res­o­lu­tion, and encom­pass­ing descrip­tions of their assem­bly into ordered porous struc­tures, tem­plat­ing of high­er-order porous mate­ri­als, and real­iza­tion of mul­ti­scale (e.g., micro-/me­so­porous) porous sub­strates. Exam­ples of mate­ri­als that will be dis­cussed include mono- and mul­ti-lay­er col­loidal crys­tal films, three-dimen­sion­al­ly ordered meso­porous (3DOm) car­bon and tita­nia repli­ca par­ti­cles and thin films, size-tun­able, uni­form­ly shaped zeolitic (i.e., sil­i­calilte-1) nanocrys­tals, and 3DOm-imprint­ed sin­gle crys­tal zeo­lite par­ti­cles. The result­ing tun­able porous mate­ri­als hold excit­ing impli­ca­tions for appli­ca­tions rang­ing from catal­y­sis to mol­e­c­u­lar sep­a­ra­tions, and simul­ta­ne­ous reac­tion-sep­a­ra­tions tech­nolo­gies.

Speaker’s Biog­ra­phy — Mark A. Sny­der obtained his B.S in Chem­i­cal Engi­neer­ing with high­est hon­ors from Lehigh Uni­ver­si­ty in 2000, and his Ph.D. in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Delaware in 2006. His doc­tor­al research on mul­ti­scale mod­el­ing of mol­e­c­u­lar trans­port in poly­crys­talline zeo­lite mem­branes was rec­og­nized with an Amer­i­can Insti­tute of Chem­i­cal Engi­neers (AIChE) Grad­u­ate Research Award in 2005. Dur­ing his doc­tor­al work, he was also award­ed the T.W. Fras­er and Shirley Rus­sell Teach­ing Fel­low­ship (2004), the Robert L. Pig­ford Teach­ing Assis­tant Award (2003), and the Robert L. Pig­ford Grad­u­ate Fel­low­ship (2000). Sny­der car­ried out post-doc­tor­al research in the Depart­ment of Chem­i­cal Engi­neer­ing and Mate­ri­als Sci­ence at the Uni­ver­si­ty of Min­neso­ta from 2006–2008, inves­ti­gat­ing the benign syn­the­sis of met­al oxide nanopar­ti­cles and their assem­bly into mono- to mul­ti-lay­er porous thin films, perms­e­lec­tive encap­su­la­tion of liv­ing cells towards nov­el ther­a­peu­tics, and for­ma­tion of repli­ca porous struc­tures. Sny­der joined Lehigh University’s Depart­ment of Chem­i­cal Engi­neer­ing in August 2008 as an Assis­tant Pro­fes­sor, and was award­ed a P.C. Rossin Assis­tant Pro­fes­sor­ship in June 2009, a posi­tion that he will hold through 2011. At Lehigh, Snyder’s Porous and Func­tion­al­ized Nano­ma­te­ri­als Lab focus­es on the ratio­nal design and engi­neer­ing of func­tion­al­ized inor­gan­ic nanopar­ti­cles and porous mate­ri­als pri­mar­i­ly for catal­y­sis, mem­brane-based sep­a­ra­tions, and inte­grat­ed reac­tion-sep­a­ra­tion tech­nolo­gies span­ning appli­ca­tions in bio­fu­els, renew­able chem­i­cals, dye-sen­si­tized solar cells, and car­bon cap­ture.

2010 Spring Symposium

 
Dr. William F. Schnei­der
Pro­fes­sor, Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing
Con­cur­rent Pro­fes­sor, Depart­ment of Chem­istry and Bio­chem­istry
Uni­ver­si­ty of Notre Dame

Abstract — Het­ero­ge­neous catal­y­sis enabled a rev­o­lu­tion in the 20th cen­tu­ry in terms of mankind’s abil­i­ty to turn moth­er nature’s mate­ri­als into use­ful prod­ucts for soci­ety. In most cas­es, these appli­ca­tions have pre­ced­ed rather than fol­lowed detailed under­stand­ing of cat­alyt­ic mate­ri­als and mech­a­nisms. In order to meet the increas­ing demands of ener­gy sus­tain­abil­i­ty and envi­ron­men­tal pro­tec­tion, catal­y­sis sci­ence and appli­ca­tion in the 21st cen­tu­ry has to be dri­ven by basic insights into how mate­ri­als func­tion and how they can be improved. The advent of first-prin­ci­ples sim­u­la­tions based on den­si­ty func­tion­al the­o­ry (DFT), which are able to reli­ably sim­u­late chem­i­cal struc­tures and reac­tions at the mol­e­c­u­lar scale, has been instru­men­tal in the recent renais­sance in het­ero­ge­neous catal­y­sis research. In this talk, I will illus­trate the capa­bil­i­ties and chal­lenges of apply­ing these sim­u­la­tion tools in the con­text of the cat­alyt­ic chem­istry of nitro­gen oxides (NOx). NOx is an unwant­ed by-prod­uct of com­bus­tion and is par­tic­u­lar­ly dif­fi­cult to remove from lean com­bus­tion sources, such as diesel engines. NOx also has rather com­plex chem­istry that presents spe­cial chal­lenges to sim­u­la­tion. I will describe some of our suc­cess­es in under­stand­ing NOx chem­istry from first-prin­ci­ples, with a par­tic­u­lar empha­sis on recent work to cap­ture the essen­tial fea­tures of the beguil­ing sim­ple cat­alyt­ic oxi­da­tion of NO to NO₂ in mol­e­c­u­lar mod­els, to rec­on­cile these mod­els with exper­i­men­tal results, and to use these insights to guide the selec­tion of new and improved cat­a­lysts.

Speaker’s Biog­ra­phy — Bill Schneider’s exper­tise is in chem­i­cal appli­ca­tions of den­si­ty func­tion­al the­o­ry (DFT) sim­u­la­tions. He began his pro­fes­sion­al career in the Ford Motor Com­pa­ny Research Lab­o­ra­to­ry work­ing on a vari­ety of prob­lems relat­ed to the envi­ron­men­tal impacts of auto­mo­bile emis­sions. There he devel­oped an inter­est in the cat­alyt­ic chem­istry of NOx for diesel emis­sions con­trol, and he has pub­lished exten­sive­ly on the chem­istry and mech­a­nisms of NOx decom­po­si­tion, selec­tive cat­alyt­ic reduc­tion, trap­ping, and oxi­da­tion catal­y­sis. In 2004 he joined the Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing fac­ul­ty at the Uni­ver­si­ty of Notre Dame as a tenured Asso­ciate Pro­fes­sor. At Notre Dame he has con­tin­ued his research into the the­o­ry and mol­e­c­u­lar sim­u­la­tion of het­ero­ge­neous catal­y­sis, with par­tic­u­lar empha­sis on reac­tion envi­ron­ment effects on cat­alyt­ic mate­ri­als and their impli­ca­tions for mech­a­nism and reac­tiv­i­ty. He has co-authored more than 90 papers and book chap­ters.

2010 Spring Symposium

 
Mark Stew­art
Research Sci­en­tist
Hydro­car­bons & Ener­gy and Alter­na­tive Feed­stocks
The Dow Chem­i­cal Com­pa­ny

Abstract — Tech­nol­o­gy devel­op­ment and mar­ket forces are con­verg­ing to por­tend the unthink­able: viable options for olefin pro­duc­tion with­out a steam crack­er. The Alter­na­tive Feed­stock Pro­gram at Dow Chem­i­cal is imple­ment­ing routes to olefin deriv­a­tives that would have been unthink­able a decade ago. This talk will describe these efforts and, in par­tic­u­lar, high­light the emer­gence of bio-based poly­eth­yl­ene made by cat­alyt­ic dehy­dra­tion of ethanol to form eth­yl­ene. Next gen­er­a­tion bioethanol options are described. The extinc­tion of steam crack­ers is not immi­nent, but new tech­nolo­gies are find­ing their place. New alco­hol pro­duc­tion brings both vibran­cy and uncer­tain­ty to olefin pro­duc­tion.

Speaker’s Biog­ra­phy — Mark began his career with Dow in 1998 work­ing in the Dow’s Cen­tral Research lab­o­ra­to­ries in Reac­tion Engi­neer­ing on a vari­ety of pro­grams rang­ing from tra­di­tion­al semi-batch poly­ol reac­tors to mod­el­ing polyurethane reac­tions on straw in the pro­duc­tion of wheat par­ti­cle­board. In 2002 he moved to Hydro­car­bons Research for the sup­port of Styrene Plants, dur­ing which time he worked on sev­er­al projects receiv­ing Tech Cen­ter Awards val­ued in total over $60MM and inte­grat­ed the tech­ni­cal reac­tor mod­els into the com­mer­cial cost mod­els to opti­mize over­all pro­duc­tion. In 2006 Mark tran­si­tioned to olefins research where he is cur­rent­ly work­ing on the intro­duc­tion of new tech­nolo­gies into tra­di­tion­al steam crack­ers and the devel­op­ment of alter­na­tive feed­stocks for olefins pro­duc­tion. Dur­ing this time he worked close­ly in Dow’s effort in Brazil for the con­ver­sion of ethanol to poly­eth­yl­ene.

Mark earned his bachelor’s degree in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Wash­ing­ton in 1997, his Master’s in Chem­i­cal Engi­neer­ing Prac­tice from MIT in 1998, and his Master’s in Busi­ness Admin­is­tra­tion from the Uni­ver­si­ty of Texas in 2008.

2010 Spring Symposium

 
Paul J. Dauen­hauer
Uni­ver­si­ty of Mass­a­chu­setts, Amherst


Abstract — Par­ti­cles of micro­crys­talline cel­lu­lose approx­i­mate­ly 300 µm in diam­e­ter ther­mal­ly decom­pose on high tem­per­a­ture (700 °C) inor­gan­ic sur­faces coat­ed with Rh-based reform­ing cat­a­lyst to an inter­me­di­ate liq­uid. The inter­me­di­ate liq­uid main­tains con­tact with the sur­face per­mit­ting high heat trans­fer which results in an inter­nal ther­mal gra­di­ent with­in the par­ti­cle. Con­ver­sion from sol­id to liq­uid occurs along the inter­nal ther­mal gra­di­ent final­ly result­ing in a ful­ly liq­uid droplet which com­plete­ly boils to vapors.

Speaker’s Biog­ra­phy — Paul Dauen­hauer is an assis­tant pro­fes­sor of Chem­i­cal Engi­neer­ing at the Uni­ver­si­ty of Mass­a­chu­setts, Amherst. His research cur­rent­ly exam­ines the chem­istry of bio­mass pyrol­y­sis in the pres­ence of reform­ing and com­bus­tion cat­a­lysts. He was for­mer­ly a Senior Research Engi­neer with the Dow Chem­i­cal Com­pa­ny in Mid­land, MI, and Freeport, TX, as part of both Core R&D – Reac­tion Engi­neer­ing and Chem­istry and Catal­y­sis, as well as the Hydro­car­bons and Ener­gy R&D divi­sion. He was the co-inven­tor of the process Reac­tive Flash Volatiliza­tion for the con­ver­sion of bio­mass to syn­the­sis gas at mil­lisec­ond res­i­dence times, and he cur­rent­ly is a co-author of four patent appli­ca­tions relat­ed to cat­alyt­ic bio­mass pro­cess­ing. For­mer employ­ment includ­ed Cargill, Inc. at Gainesville, GA, as part of the Grain & Oilseeds Divi­sion as well as Wah­peton, ND, as part of the Sweet­en­ers divi­sion for the wet milling of maize.

2010 Spring Symposium

 
Dustin W. Fick­el and Raul F. Lobo
*Cen­ter for Cat­alyt­ic Sci­ence and Tech­nol­o­gy
Depart­ment of Chem­i­cal Engi­neer­ing
Uni­ver­si­ty of Delaware
Newark, Delaware 19716

Abstract — Nitro­gen oxides (NOx) are a major atmos­pher­ic pol­lu­tant pro­duced through the com­bus­tion of fos­sil fuels in inter­nal com­bus­tion engines. Cop­per-exchanged zeo­lites are promis­ing as selec­tive cat­alyt­ic reduc­tion cat­a­lysts for the direct con­ver­sion of NO into N₂ and O₂, and recent reports have shown the enhanced per­for­mance of Cu-CHA cat­a­lysts over oth­er zeo­lite frame­works in the NO decom­po­si­tion of exhaust gas streams.

In the present study, Rietveld refine­ment of vari­able-tem­per­a­ture XRD syn­chro­tron data obtained for Cu-SSZ-13 and Cu-SSZ-16 is used to inves­ti­gate the loca­tion of cop­per cations in the zeo­lite pores and the effect of tem­per­a­ture on these sites and on frame­work sta­bil­i­ty. The XRD pat­terns show that the ther­mal sta­bil­i­ty of SSZ-13 is increased sig­nif­i­cant­ly when cop­per is exchanged into the frame­work com­pared with the acid form of the zeo­lite, H-SSZ-13. Cu-SSZ-13 is also more ther­mal­ly sta­ble than Cu-SSZ-16. From the refined dif­frac­tion pat­terns, the atom­ic posi­tions of atoms, cop­per loca­tions and occu­pan­cies, and ther­mal dis­place­ment para­me­ters were deter­mined as a func­tion of tem­per­a­ture for both zeo­lites. Cop­per is found in the cages coor­di­nat­ed to three oxy­gen atoms of the six-mem­bered rings. This study also shows the enhanced per­for­mance of cop­per exchanged small-pore zeo­lites towards the selec­tive cat­alyt­ic reduc­tion of nitric oxide com­pared to Cu-ZSM-5 after hydrother­mal­ly treat­ing the zeo­lites.

* Fick­el, D.W., Lobo, R.F., Cop­per Loca­tion Study of Cu-SSZ-13 and Cu-SSZ-16 Vari­able Tem­per­a­ture XRD Riet­feld Refine­ment, J. Phys. Chem. C, DOI: 10.1021/jp9105025.

2010 Spring Symposium

 
Ray­mond J. Gorte
Chem­i­cal & Bio­mol­e­c­u­lar Engi­neer­ing
Uni­ver­si­ty of Penn­syl­va­nia
Philadel­phia, PA 19104 USA
gorte@​seas.​upenn.​edu

Abstract — SOFC and SOE are based on elec­trolytes that are oxy­gen-ion con­duc­tors. SOFC can there­fore oper­ate on a wide range of fuels, includ­ing methane and oth­er hydro­car­bons. Like­wise, elec­trol­y­sis of CO₂ is fea­si­ble in an SOE. How­ev­er, to allow sta­ble oper­a­tion with a wider range of feeds to the elec­trodes, new elec­trode mate­ri­als must be devel­oped. This talk will describe the meth­ods being devel­oped at Penn that allow the elec­trode com­po­si­tion and struc­ture to be var­ied eas­i­ly. Results for both fuel- and air-side elec­trodes will be dis­cussed.

Speaker’s Biog­ra­phy — Dr. 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, Dr. Gorte 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). His present research inter­ests are focused on elec­trodes for sol­id-oxide fuel cells and on ther­mo­dy­nam­ic stud­ies of redox prop­er­ties with oxi­da­tion cat­a­lysts. 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.