Intrinsic Deactivation in Cobalt-Catalyzed Fischer-Tropsch Synthesis

Meeting Program — April 2014

 
Gabor Kiss, Stu­art Soled, Chris Kliew­er
Exxon­Mo­bil Res. and Eng. Co.
Annan­dale, NJ

gabor.​kiss@​exxonmobil.​com
 
Abstract — In this paper, we describe three intrin­sic deac­ti­va­tion modes observed in exper­i­men­tal cobalt Fis­ch­er-Trop­sch syn­the­sis cat­a­lysts: cobalt oxi­da­tion reversible by mild hydro­gen treat­ment, cobalt agglom­er­a­tion, and cobalt-sup­port mixed oxide for­ma­tion. All three mech­a­nisms involve redox trans­for­ma­tion of the cat­alyt­i­cal­ly active cobalt met­al.
 
Gabor_KissBiog­ra­phy — Gabor Kiss received his M.Sc. in chem­i­cal engi­neer­ing from the Uni­ver­si­ty of Veszprem (now Pan­non Uni­ver­si­ty), Hun­gary, in 1981. He worked in the Hun­gar­i­an oil indus­try for eight years before enrolling the grad­u­ate school at the Uni­ver­si­ty of Mia­mi. After receiv­ing his Ph.D. in chem­istry in 1993, he accept­ed a posi­tion at Exxon’s (now Exxon­Mo­bil) Cor­po­rate Research Lab­o­ra­to­ries in Clin­ton, NJ, where he is cur­rent­ly a Sr. Sci­en­tif­ic Asso­ciate. His research inter­ests include the kinet­ics, ther­mo­dy­nam­ics, and mech­a­nism of both homo­ge­neous and het­ero­ge­neous cat­alyt­ic process­es. He has pub­lished 26 peer-reviewed papers and has 38 patents.

Explor­ing the Cat­alytic Prop­er­ties of Cu/SSZ-13 using NO Oxi­da­tion and Stan­dard Selec­tive Reduc­tion of NO with NH3

2014 Spring Symposium

 
Fabio H. Ribeiro*1, W. Nicholas Del­gass1, William F. Schnei­der2, Jef­frey T. Miller3, Alek­sey Yez­erets4, Truno­joyo Anggara2, Christo­pher Paoluc­ci2, Shane A. Bates1, Anuj Ver­ma1, and Atish Parekh1
1School of Chem­i­cal Engi­neer­ing, Pur­due Uni­ver­si­ty, West Lafayette, Indi­ana 47907 (USA)
2Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing, Uni­ver­si­ty of Notre Dame, Notre Dame, Indi­ana
46556 (USA)
3Argonne Nation­al Lab­o­ra­to­ry, Darien, IL 60439 (USA)
4Cum­mins Inc., Colum­bus, IN 47202 (USA)

*fabio@​purdue.​edu
 
Abstract — The Cu/SSZ-13 cat­a­lyst (CHA frame­work) is pre­ferred for SCR appli­ca­tions because it shows both SCR per­for­mance and hydrother­mal sta­bil­i­ty. In this work, the site require­ments of the Stan­dard SCR and NO oxi­da­tion reac­tions have been stud­ied on Cu/SSZ-13. Based on an inte­grat­ed exper­i­men­tal and mod­el­ing approach, the active site for the Stan­dard SCR on Cu/SSZ-13 has been assigned to an iso­lat­ed Cu ion locat­ed near the 6 mem­ber rings of SSZ-13, while NO oxi­da­tion required local Cu – O – Cu bonds in the 8 mem­ber cage of SSZ-13. The for­ma­tion of local Cu – O – Cu bonds was a result of sat­u­ra­tion of the num­ber of favor­able Al pairs near the 6 mem­ber ring to sta­bi­lize iso­lat­ed Cu ions. The vari­a­tion of the NO oxi­da­tion and the SCR rates of reac­tion with Cu/Al ratios was thus a cat­alyt­ic con­se­quence of dif­fer­ent Cu ion con­fig­u­ra­tions with­in SSZ-13. The work­ing state of cat­a­lyst under SCR, more­over, was exam­ined by Operan­do X – Ray Absorp­tion Spec­troscopy (XAS). Under reac­tion con­di­tions, the Stan­dard SCR involved a redox mech­a­nism with both Cu(I) and Cu (II) species present. Fur­ther exper­i­ments using operan­do XAS to probe the redox cycle of Cu were car­ried out by remov­ing the oxi­diz­ing half-reac­tion, which pro­duced most­ly the Cu(I) state, and then the reduc­ing half reac­tion, which pro­duced most­ly the Cu(II) state. Thus, any mech­a­nism of Stan­dard SCR has to incor­po­rate a redox cycle. In sum­ma­ry, the stan­dard SCR on Cu-SSZ13 required iso­lat­ed Cu ions to under­go a redox cycle near the 6 mem­ber ring of SSZ13.
 
Fabio_H_RibeiroBiog­ra­phy — Fabio H. Ribeiro is cur­rent­ly the R. Nor­ris and Eleanor Shreve Pro­fes­sor of Chem­i­cal Engi­neer­ing at the School of Chem­i­cal Engi­neer­ing, Pur­due Uni­ver­si­ty. He received his Ph.D. degree from Stan­ford Uni­ver­si­ty in 1989, held a post-doc­tor­al fel­low­ship at the Uni­ver­si­ty of Cal­i­for­nia – Berke­ley, and was on the Worces­ter Poly­tech­nic Insti­tute fac­ul­ty before join­ing Pur­due Uni­ver­si­ty in August 2003. His research inter­ests con­sist of the kinet­ics of het­ero­ge­neous cat­alyt­ic reac­tions and cat­a­lyst char­ac­ter­i­za­tion by in situ tech­niques. He was Chair for AIChE’s Catal­y­sis and Reac­tion Engi­neer­ing Divi­sion (2010) and is edi­tor for Jour­nal of Catal­y­sis.

Nanoporous Mate­ri­als for Solar Fuel Pro­duc­tion

2014 Spring Symposium

 
Feng Jiao
Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing
Uni­ver­si­ty of Delaware
Newark, DE 19716

jiao@​udel.​edu
 
Abstract — Solar fuel pro­duc­tion is an impor­tant tech­no­log­i­cal chal­lenge, con­sid­er­ing that the ener­gy of sun­light that strikes the earth’s sur­face in an hour is suf­fi­cient to meet our ener­gy demands for a year. Irre­spec­tive of the approach that is pur­sued, oxy­gen evo­lu­tion from water is the crit­i­cal reac­tion, because water is the only cheap, clean and abun­dant source that is capa­ble of com­plet­ing the redox cycle for pro­duc­ing either hydro­gen (from H2O) or car­bona­ceous fuels (from CO2) on a ter­awatt scale. Here, we will show our recent stud­ies in meso­porous spinel sys­tems, which sug­gest the met­al sit­ting at the octa­he­dral site has huge impact on the water oxi­da­tion activ­i­ty of spinel cat­a­lysts. Anoth­er top­ic will be dis­cussed in the pre­sen­ta­tion is the devel­op­ment of selec­tive and robust CO2 reduc­tion elec­tro­cat­a­lyst. We will present a nanoporous Ag elec­tro­cat­a­lyst, which is able to elec­tro­chem­i­cal­ly reduce CO2 to CO with a ~92% selec­tiv­i­ty at a rate (i.e. cur­rent) of over 3000 times high­er than its poly­crys­talline coun­ter­part under a mod­er­ate over­po­ten­tial of less than 0.50 V. Such an excep­tion­al­ly high activ­i­ty is a result of a large elec­tro­chem­i­cal sur­face area (ca. 150 times larg­er) and intrin­si­cal­ly high activ­i­ties (ca. 20 times high­er) com­pared to poly­crys­talline Ag.
 
Feng_JiaoBiog­ra­phy — Feng Jiao obtained his BS in chem­istry at Fudan Uni­ver­si­ty (2001) and his PhD degree in Chem­istry at Uni­ver­si­ty of St Andrews (Scot­land, 2008), before mov­ing to Lawrence Berke­ley Nation­al Lab­o­ra­to­ry as a post­doc schol­ar. He spent two years in Berke­ley devel­op­ing solar fuel tech­nol­o­gy and joined in the Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing Depart­ment at the Uni­ver­si­ty of Delaware as an assis­tant pro­fes­sor in 2010. He has already pub­lished more than 35 jour­nal papers in lead­ing sci­en­tif­ic jour­nals, such as Nature Com­mu­ni­ca­tions, J. Am. Chem. Soc., and Angew. Chem. Int. Ed. His research activ­i­ties include syn­the­sis of nanoporous mate­ri­als and their poten­tial appli­ca­tions in ener­gy stor­age and con­ver­sion.

Sur­face Reac­tions of Biomass-Derived Poly­ols on Metal Oxides and Sup­ported Metal Cat­a­lysts

2014 Spring Symposium

 
Carsten Siev­ers
Geor­gia Insti­tute of Tech­nol­o­gy
School of Chem­i­cal & Bio­mol­e­c­u­lar Engi­neer­ing
Atlanta, GA 30332

carsten.​sievers@​chbe.​gatech.​edu
 
Abstract — Aque­ous phase process­es are expect­ed to play a key role in the pro­duc­tion of renew­able chem­i­cals and fuels from bio­mass. Facile sep­a­ra­tion makes het­ero­ge­neous cat­a­lysts an attrac­tive option for achiev­ing high effi­cien­cy in these process­es. Unfor­tu­nate­ly, lit­tle is known about the sur­face chem­istry of bio­mass-derived oxy­genates in an aque­ous envi­ron­ment. How­ev­er, this knowl­edge will be need­ed to improve the activ­i­ty, selec­tiv­i­ty, and sta­bil­i­ty of cat­a­lysts for aque­ous phase process­es to the lev­el we are used to in vapor phase reac­tions. This pre­sen­ta­tion will focus on sur­face inter­ac­tions of bio­mass-derived oxy­genates with met­al oxides (Al2O3, TiO2, ZrO2, CeO2, MgO, Nb2O5) and sup­port­ed met­al cat­a­lysts (Pt/Al2O3).

The sur­face chem­istry of aque­ous solu­tions of poly­ols on polar met­al oxides is strong­ly affect­ed by the com­pe­ti­tion between water and the poly­ols for adsorp­tion sites. Direct­ed inter­ac­tions with spe­cif­ic sur­face sites dom­i­nate. Even in the pres­ence of water, poly­ols with suf­fi­cient spa­tial sep­a­ra­tion between their alco­hol groups (e.g. glyc­erol) can chemisorb on Lewis acid sites form­ing sta­ble mul­ti­den­tate sur­face species. The fre­quen­cies of C-O stretch­ing vibra­tions of par­tic­i­pat­ing groups scale lin­ear­ly with the elec­troneg­a­tiv­i­ty of the met­al atom pro­vid­ing an indi­ca­tion for reac­tiv­i­ty trends in acid cat­alyzed reac­tions, such as dehy­dra­tion. The sur­face species described here can also sta­bi­lize met­al oxides like γ-Al2O3 against hydrol­y­sis in hot liq­uid water that would oth­er­wise dete­ri­o­rate the mate­r­i­al. Direct dehy­dra­tion of adsorbed glyc­erol on the Lewis acid sites of Nb2O5 yields hydrox­y­ace­tone as the main prod­ucts, where­as acrolein is formed when Brøn­st­ed acid sites are involved in the con­ver­sion.

In-situ spec­tro­scop­ic stud­ies pro­vide addi­tion­al insight into the kinet­ics of the con­ver­sion of oxy­genates in water. Specif­i­cal­ly, ATR-IR spec­troscopy is used to demon­strate that Pt/Al2O3 read­i­ly acti­vates bio­mass-derived oxy­genates, such as glyc­erol, to form sur­face bound CO on the Pt par­ti­cles. The num­ber of avail­able sur­face sites is increased when Pt/γ-Al2O3 is cleaned by hydro­gen and oxy­gen sat­u­rat­ed water. After this pre­treat­ment, some of the Pt sites that bind bridg­ing CO show activ­i­ty for the water-gas-shift reac­tion even at room tem­per­a­ture.
 
Model Release-YESBiog­ra­phy — Carsten Siev­ers obtained his Diplom and Dr. rer nat. degrees in Tech­ni­cal Chem­istry at the Tech­ni­cal Uni­ver­si­ty of Munich, Ger­many. Under the guid­ance of Prof. Johannes A. Lercher he worked on het­ero­ge­neous cat­a­lysts for var­i­ous process­es in petro­le­um refin­ing includ­ing hydro­gena­tion of aro­mat­ics in Diesel fuel, alky­la­tion, alka­ne acti­va­tion, and cat­alyt­ic crack­ing. Addi­tion­al research projects includ­ed nov­el cat­alyt­ic sys­tem, such as sup­port­ed ion­ic liq­uids. In 2007, he moved to the Geor­gia Insti­tute of Tech­nol­o­gy to work with Profs. Christo­pher W. Jones and Pradeep K. Agraw­al as a post­doc­tor­al fel­low. His pri­ma­ry focus was the devel­op­ment of cat­alyt­ic process­es for bio­mass depoly­mer­iza­tion and syn­the­sis of bio­fu­els. He joined the fac­ul­ty at the Geor­gia Insti­tute of Tech­nol­o­gy in 2009. His research group is devel­op­ing cat­alyt­ic process­es for the sus­tain­able pro­duc­tion of fuels and chem­i­cals. Spe­cif­ic foci are on the sta­bil­i­ty and reac­tiv­i­ty of sol­id cat­a­lysts in aque­ous phase, sur­face chem­istry of oxy­genates in water, applied spec­troscopy, physic­o­chem­i­cal char­ac­ter­i­za­tion of sol­id mate­ri­als, syn­the­sis of well-defined cat­a­lysts, methane con­ver­sion, pyrol­y­sis, and gasi­fi­ca­tion. He is Pres­i­dent of the South­east­ern Catal­y­sis Soci­ety and Pro­gram Chair of the ACS Divi­sion of Catal­y­sis Sci­ence & Tech­nol­o­gy.

Zn Mod­i­fi­ca­tion of Pt(111) for the Hydrodeoxy­gena­tion of Aldoses

2014 Spring Symposium

 
Jesse R. McManus, Eddie Martono, & John M. Vohs
Uni­ver­si­ty of Penn­syl­va­nia
 
Abstract — The high oxy­gen con­tent and mul­ti­ple func­tion­al groups in bio­mass-derived plat­form mol­e­cules like glu­cose pose an inter­est­ing reac­tion engi­neer­ing chal­lenge for the con­ver­sion of bio­mass to val­ue-added fuels and chem­i­cals. The key to under­stand­ing the reac­tion path­ways nec­es­sary for these con­ver­sions lies in elu­ci­dat­ing reac­tion active sites on cat­alyt­i­cal­ly rel­e­vant sur­faces and iden­ti­fy­ing the role of each func­tion­al­i­ty exhib­it­ed by the feed mol­e­cule in the reac­tion mech­a­nism. In this study, tem­per­a­ture pro­grammed des­orp­tion (TPD) and high res­o­lu­tion elec­tron ener­gy loss (HREEL) spec­troscopy are uti­lized to probe the reac­tion path­way of the bio­mass-rel­e­vant glu­cose mol­e­cule, as well as mod­el aldos­es glyc­er­alde­hyde and gly­co­lalde­hyde, and sim­ple alde­hyde acetalde­hyde on a Pt cat­a­lyst sur­face. The effects of mod­i­fi­ca­tion of the Pt(111) sur­face with oxyphilic Zn adatoms are explored with regard to hydrodeoxy­gena­tion chem­istry, and reac­tion mech­a­nisms are pro­posed. With all mol­e­cules stud­ied, it was found that Zn addi­tion to Pt(111) result­ed in an increase in the bar­ri­er for C-H and C-C scis­sion, as well as notable activ­i­ty for deoxy­gena­tion at the alde­hyde oxy­gen as a func­tion of polyal­co­hol con­tent. These results help elu­ci­date the role of mul­ti­ple alco­hol func­tion­al­i­ties in bio­mass-derived oxy­genates and high­light the poten­tial of using alloy effects to mod­i­fy cat­alyt­ic chem­istry.
 
Jess_R_McManusBiog­ra­phy — Dr. Jesse R. McManus recent­ly com­plet­ed his PhD research in Chem­i­cal Engi­neer­ing at the Uni­ver­si­ty of Penn­syl­va­nia under the tute­lage of Prof. John M. Vohs, suc­cess­ful­ly defend­ing his the­sis “Reac­tion Char­ac­ter­i­za­tion of Bio­mass-Derived Oxy­genates on Noble Met­al Cat­a­lysts”. In 2009, he received his BSE in Chem­i­cal Engi­neer­ing at Tulane Uni­ver­si­ty, grad­u­at­ing Sum­ma Cum Laude with an Hon­ors dis­tinc­tion. Dur­ing his stud­ies, Dr. McManus has received sev­er­al awards for his aca­d­e­m­ic accom­plish­ments, includ­ing the Tulane-Richards Schol­ar­ship for Aca­d­e­m­ic Excel­lence, The R.C. Reed Schol­ar Award for aca­d­e­m­ic achieve­ment and promise for the future, and the Doc­tor­al Franklin Schol­ar Award for stu­dents with high promise to suc­ceed in cre­ative research at the cut­ting edge of their dis­ci­pline. In the spring, Dr. McManus plans to depart from aca­d­e­m­ic research and pur­sue a career in the ener­gy sec­tor with a major ener­gy com­pa­ny.

Alkene Metathe­sis for Propy­lene Pro­duc­tion over W-based Cat­a­lysts: Insights from Multi-Functional Cat­a­lysts and Met­al­la­cy­clobu­tanes

2014 Spring Symposium

 
Christo­pher P. Nicholas

 
Abstract — Tung­sten oxide sup­port­ed on sil­i­ca is an effi­cient cat­a­lyst for olefin metathe­sis used in indus­tri­al process­es since the 1960s. Sev­er­al ele­ments point to iso­lat­ed met­al cen­ters as the active sites, and from the Chau­vin mech­a­nism, it is rea­son­able to expect that car­bene species are involved, pos­si­bly bear­ing an oxide lig­and in the metal’s lig­and sphere. Owing to the strate­gic impor­tance of olefins as build­ing blocks for the world chem­i­cal indus­try, devel­op­ment of effi­cient process­es is of utmost rel­e­vance. More specif­i­cal­ly, tai­lored het­ero­ge­neous cat­a­lysts with known structure–activity rela­tion­ships may improve life­times and have high­er num­bers of active sites.

With our col­lab­o­ra­tors, we have been study­ing tung­sten hydride sup­port­ed on alu­mi­na pre­pared by the sur­face organometal­lic chem­istry method as an active pre­cur­sor for metathe­sis process­es at low tem­per­a­ture and pres­sure. Taoufik, et​.al. showed that eth­yl­ene can be con­vert­ed to propy­lene at very high selec­tiv­i­ties of 99% via a tri-func­tion­al mech­a­nism involv­ing dimer­iza­tion, iso­mer­iza­tion and cross-metathe­sis of eth­yl­ene and the pro­duced 2-butene. Recent­ly, via a con­tact time study we revealed that the dimer­iza­tion of eth­yl­ene to 1-butene is the pri­ma­ry and also the rate lim­it­ing step in this reac­tion and results in deac­ti­va­tion of the cat­a­lyst due to a side reac­tion like olefin poly­mer­iza­tion pro­duc­ing car­bona­ceous deposits on the cat­a­lyst.

With that knowl­edge, we have also inves­ti­gat­ed per­for­mance of the cat­a­lyst in the pres­ence of eth­yl­ene and butenes. At low tem­per­a­ture (120 °C) in the cross-metathe­sis of eth­yl­ene and 2-butene, the cat­a­lyst deac­ti­vates notably with time on stream. How­ev­er, at 150 °C, the cat­a­lyst was sta­ble with time and there­by gave a high pro­duc­tiv­i­ty in propy­lene. The ratio of eth­yl­ene to trans-2-butene was also stud­ied, and the W-H/Al2O3 cat­a­lyst is sta­ble and high­ly selec­tive to propy­lene even at sub-sto­i­chio­met­ric eth­yl­ene ratios.

Sur­pris­ing­ly, we have also been able to obtain propy­lene in high yields from butene only feeds. 1-butene and 2-butene are both able to be con­vert­ed into propy­lene at high­er selec­tiv­i­ty than expect­ed due to iso­mer­iza­tion and metathe­sis occur­ring simul­ta­ne­ous­ly. Then, by study­ing isobutene / 2-butene cross-metathe­sis, we observed that the cat­alyt­ic cycle involv­ing the less ster­i­cal­ly hin­dered tungsta­cy­clobu­tane inter­me­di­ate gov­erns the con­ver­sion rate of the cross-metathe­sis reac­tion for propy­lene pro­duc­tion from butenes and/or eth­yl­ene.
 

References

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Christopher_P_NicholasBiog­ra­phy — Chris joined UOP in 2006 after earn­ing a Ph.D. from North­west­ern Uni­ver­si­ty and work­ing in the Hard Mate­ri­als Cen­ter of Excel­lence at Sig­ma-Aldrich. He has worked in the Catal­y­sis and Explorato­ry Research depart­ments and is cur­rent­ly focused on New Mate­ri­als Research. Chris is an inven­tor or co-inven­tor on 30+ US and for­eign patents and coau­thor of 13 peer reviewed jour­nal arti­cles and a book chap­ter. He has been involved with the Chica­go Catal­y­sis Club since grad­u­ate stu­dent days and is cur­rent­ly serv­ing as the Pro­gram Chair for the Chica­go Catal­y­sis Club. Chris’ research inter­ests encom­pass the gamut of inor­gan­ic and cat­alyt­ic tech­nolo­gies rang­ing from mate­ri­als syn­the­sis to char­ac­ter­i­za­tion to cat­a­lyst and process devel­op­ment. He has par­tic­u­lar­ly enjoyed under­stand­ing the rela­tion­ship between homo­ge­neous and het­ero­ge­neous cat­a­lysts.