Olefin Metathesis by Supported MoOx/Al2O3 Catalysts

Meeting Program — October 2017

Anisha Chakrabar­ti — Stu­dent Speak­er

Advi­sor: Israel E. Wachs
Operan­do Mol­e­c­u­lar Spec­troscopy & Catal­y­sis Lab­o­ra­to­ry
Depart­ment of Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing
Lehigh Uni­ver­si­ty, Beth­le­hem, PA 18015 USA

Abstract — The olefin metathe­sis reac­tion was com­mer­cial­ized in the late 1960s to pro­duce eth­yl­ene and 2-butene from propy­lene in the Phillips Tri­olefin Process. The reverse reac­tion, how­ev­er, is cur­rent­ly desired due to a glob­al propy­lene short­age caused by the shift to lighter feed­stocks derived from shale gas frack­ing. Het­ero­ge­neous sup­port­ed MoOx/Al2O3 cat­a­lysts are employed for olefin metathe­sis in the Shell High­er Olefin Process (SHOP) that oper­ates between room tem­per­a­ture and ~200°C.

To probe the mol­e­c­u­lar details of the sup­port­ed MoOx/Al2O3 cat­a­lysts, a mod­ern in situ spec­troscopy approach was under­tak­en. In situ UV-vis mea­sure­ments (Eg val­ues) con­firmed the pres­ence of iso­lat­ed and oligomer­ic MoOx sur­face sites, with the lat­ter increas­ing with molyb­de­na load­ing. In situ Raman spec­troscopy revealed that at low load­ings of molyb­de­na (1 Mo atoms/nm2), only iso­lat­ed dioxo (O=)2MoO2 sur­face sites are present. As the molyb­de­na load­ing is increased (1–4.6 Mo atoms/nm2), oligomer­ic mono-oxo O=MoO4 sur­face sites co-exist with the iso­lat­ed dioxo (O=)2MoO2 sur­face sites. Above mono­lay­er load­ings (>4.6 Mo atoms/nm2), crys­talline MoO3 nanopar­ti­cles are also present. In situ IR indi­cates that the iso­lat­ed dioxo MoO4 sites are anchored at more basic HO-μ1-AlIV sur­face hydrox­yls, while the sur­face oligomer­ic mono-oxo sites are anchored to more acidic HO-μ1/3-AlV/VI sur­face hydrox­yls. Propy­lene metathe­sis at reac­tion con­di­tions sug­gest that the iso­lat­ed dioxo (O=)2MoO2 sur­face site may still be present after acti­va­tion of the mono-oxo sur­face sites with propy­lene. In situ UV-vis dur­ing propy­lene metathe­sis indi­cates that Mo+6 sites are dom­i­nant dur­ing propy­lene metathe­sis due to the pres­ence of unre­duced sur­face dioxo Mo+6O4 sites and re-oxi­da­tion of reduced Mo+4 sites by propy­lene back to Mo+6=CH2 and Mo+6=CHCH3 reac­tion inter­me­di­ates. The sur­face chem­istry was chem­i­cal­ly probed by C3H6-TPSR that ini­tial­ly formed oxy­genat­ed prod­ucts (CH3CHO, H2CO, CH3COCH3, H2O and CO/CO2) dur­ing cat­a­lyst acti­va­tion. The reac­tiv­i­ty of the acti­vat­ed cat­a­lysts to butene pro­gres­sive­ly increased with molyb­de­na load­ing, indi­cat­ing that the oligomer­ic mono-oxo MoOx sites are much more active than iso­lat­ed dioxo MoO4 sites for olefin metathe­sis. The crys­talline MoO3 nanopar­ti­cles, how­ev­er, were found to be inac­tive for metathe­sis. This pre­sen­ta­tion will address the fun­da­men­tal mol­e­c­u­lar and struc­tur­al details of the sup­port­ed MoOx/Al2O3 cat­a­lysts dur­ing propy­lene metathe­sis and estab­lish their struc­ture-activ­i­ty rela­tion­ships.

Converting CO2 via Thermocatalysis and Electrocatalysis

Meeting Program — October 2017

Jingguang Chen
Jing­guang Chen
Thay­er Lind­s­ley Pro­fes­sor of Chem­i­cal Engi­neer­ing
Colum­bia Uni­ver­si­ty


Abstract — Ris­ing atmos­pher­ic con­cen­tra­tion of CO2 is fore­cast­ed to have poten­tial­ly dis­as­trous effects on the envi­ro­ment from its role in glob­al warm­ing and ocean acid­i­fi­ca­tion. Con­vert­ing CO2 into valu­able chem­i­cals and fuels is one of the most prac­ti­cal routes for reduc­ing CO2 emis­sions while fos­sil fuels con­tin­ue to dom­i­nate the ener­gy sec­tor. The cat­alyt­ic reduc­tion of CO2 by H2 can lead to the for­ma­tion of three types of prod­ucts: CO through the reverse water-gas shift (RWGS) reac­tion, methanol via selec­tive hydro­gena­tion, and methane by the metha­na­tion path­way. In the cur­rent talk we will first describe our efforts in con­trol­ling the cat­alyt­ic selec­tiv­i­ty for the three prod­ucts using a com­bi­na­tion of DFT cal­cu­la­tions and sur­face sci­ence stud­ies over sin­gle crys­tal sur­faces, cat­alyt­ic eval­u­a­tion of sup­port­ed cat­a­lysts, and in-situ char­ac­ter­i­za­tion under reac­tion con­di­tions. Next, we will dis­cuss our efforts in con­vert­ing CO2 with­out using H2. This is moti­vat­ed by the fact that ~95% of H2 is gen­er­at­ed from hydro­car­bon-based feed­stocks, pro­duc­ing CO2 as a byprod­uct. We will present two approach­es to avoid using H2 for CO2 con­ver­sion. The first approach involves the uti­liza­tion of light alka­nes, such as ethane, to direct­ly reduce CO2 via the dry reform­ing path­way to pro­duce syn­the­sis gas (C2H6 + 2CO2 → 4CO + 3H2) and the oxida­tive dehy­dro­gena­tion route to gen­er­ate eth­yl­ene (C2H6 + CO2 → C2H4 + CO + H2O). The sec­ond approach is the elec­trol­y­sis of CO2 to pro­duce syn­the­sis gas with con­trolled CO/H2 ratios. We will con­clude our pre­sen­ta­tion by pro­vid­ing a per­spec­tive on the chal­lenges and oppor­tu­ni­ties in con­vert­ing CO2 via var­i­ous routes in ther­mo­catal­y­sis and elec­tro­catal­y­sis.

Biog­ra­phy — Jing­guang Chen is the Thay­er Lind­s­ley Pro­fes­sor of chem­i­cal engi­neer­ing at Colum­bia Uni­ver­si­ty, with a joint appoint­ment as a senior chemist at Brookhaven Nation­al Lab­o­ra­to­ry. He received his PhD degree from the Uni­ver­si­ty of Pitts­burgh and then car­ried out his Hum­boldt post­doc­tor­al research in KFA-Julich in Ger­many. After spend­ing sev­er­al years as a staff sci­en­tist at Exxon Cor­po­rate Research, he start­ed his aca­d­e­m­ic career at the Uni­ver­si­ty of Delaware in 1998 and rose to the rank of the Claire LeClaire Pro­fes­sor of chem­i­cal engi­neer­ing and the direc­tor of the Cen­ter for Cat­alyt­ic Sci­ence and Tech­nol­o­gy. He moved to Colum­bia Uni­ver­si­ty in 2012. He is the co-author of 21 US patents and over 340 jour­nal pub­li­ca­tions with over 15,000 cita­tions. He is cur­rent­ly the pres­i­dent of the North Amer­i­can Catal­y­sis Soci­ety (NACS) and an asso­ciate edi­tor of ACS Catal­y­sis. He received many catal­y­sis awards, includ­ing the 2015 George Olah award from ACS and the 2017 Robert Bur­well Lec­ture­ship from NACS.

Structure Activity Relationships in Homogeneous Catalysis

Meeting Program — September 2017

Thomas Colacot
Thomas Cola­cot
Tech­ni­cal Fel­low & Glob­al R & D Man­ag­er
John­son Matthey


Abstract — Homo­ge­neous catal­y­sis is a mol­e­c­u­lar phe­nom­e­non, where the struc­ture of the cat­a­lyst plays a sig­nif­i­cant role on the activ­i­ty and selec­tiv­i­ty of a cat­alyt­ic reac­tion. Three cas­es stud­ies will be dis­cussed dur­ing the talk to explain the phe­nom­e­na. The top­ics are

  1. High puri­ty pal­la­di­um acetate vs com­mer­cial in organ­ic syn­the­sis
  2. Ir pre cat­a­lysts for C-H acti­vat­ed bory­la­tion
  3. Gen­er­a­tion of L1Pd(0) cat­a­lysts for advanced cross cou­pling.


  • Book: New Trends in Cross Cou­pling: The­o­ry and Appli­ca­tions, ed. Thomas J. Cola­cot, Roy­al Soci­ety of Chem­istry, Cam­bridge, UK, 2015. ISBN: 978–1-84973–896-5
  • Carin C. C. Johans­son Seechurn, Thomas Sperg­er, There­sa. G. Scrase, Franziska. Schoenebeck and Thomas. J. Cola­cot*, J. Am. Chem. Soc., 2017 (DOI: 10.1021/jacs.7b01110). This work was fea­tured in the April 5 th issue of C & EN. Please see: http://​acsmeet​ings​.cen​mag​.org/​c​h​e​m​i​s​t​s​-​g​e​t​-​b​e​t​t​e​r​-​a​c​q​u​a​i​n​t​e​d​-​w​i​t​h​-​p​a​l​l​a​d​i​u​m​-​c​a​t​a​l​y​s​ts/
  • William A. Car­ole and Thomas J. Cola­cot* Chem. Eur. J, 2016, 22, 7686 (with jour­nal cov­er graph­ics – this work was fea­tured in C & EN. page 20, May 2 nd, 2016)
  • Peter G. Gild­ner, Andrew DeAn­ge­lis, and Thomas J. Cola­cot*, Org. Lett., 2016, 18 (6), 1442–1445 DOI: 10.1021/acs.orglett.6b0037
  • William A. Car­ole, Jonathan Bradley, Mis­bah Sar­war and Thomas J. Cola­cot* Org. Lett., 2015, 17 (21), 5472–5475. DOI: 10.1021/acs.orglett. 5b02835
  • Thomas. J. Cola­cot, Angew Chem. Int. Ed. 2016, 54, 15611–15612.
  • Peter G. Gild­ner and Thomas J. Cola­cot* Organometallics, 2015, 34 (23), 5497–5508. DOI: 10.1021/acs.organomet.5b00567
  • Andrew J. DeAn­ge­lis , Peter G. Gild­ner , Ruis­han Chow , and Thomas J. Cola­cot* J. Org. Chem., 2015, 80 (13), pp 6794–6813, DOI: 10.1021/acs.joc.5b01005
  • Carin C. C. Johans­son Seechurn, Vil­vanathan Sivaku­mar, Deep­ak Satoskar and Thomas J. Cola­cot*, Organometallics, 2014, 33, 3514−3522.

Biog­ra­phy — Dr. Thomas J. Cola­cot received his Ph.D. in Chem­istry from IIT Madras in 1989, fol­low­ing a B.Sc. and M.Sc. in Chem­istry from the Uni­ver­si­ty of Ker­ala in 1981 and 1983, respec­tive­ly. After his doc­tor­al and post-doc­tor­al stud­ies in the US, Dr. Cola­cot went on to pur­sue an edu­ca­tion in man­age­ment, acquir­ing an MBA from Penn­syl­va­nia State Uni­ver­si­ty in 2005, while work­ing at John­son Matthey. Before join­ing John­son Matthey in 1995, Dr. Cola­cot had also worked as a Research Asso­ciate South­ern Methodist Uni­ver­si­ty (TX, USA) on a project fund­ed by Advanced Tech­nol­o­gy Pro­gram, as an Assis­tant Pro­fes­sor at Flori­da A&M Uni­ver­si­ty, and as a Post-Doc­tor­al/Teach­ing Fel­low at Uni­ver­si­ty of Alaba­ma. Hav­ing climbed up the ranks from Devel­op­ment Asso­ciate (bench chemist), Dr. Cola­cot is cur­rent­ly the Tech­ni­cal Fel­low at John­son Matthey, USA, the high­est tech­ni­cal rank for a sci­en­tist with reports from dif­fer­ent parts of the world.

As a researcher, Dr. Cola­cot has focused on many areas of homoge­nous catal­y­sis, par­tic­u­lar­ly becom­ing pro­fi­cient in pal­la­di­um-cat­alyzed cross-cou­pling. He also has exten­sive expe­ri­ence in organometal­lic and organ­ic syn­the­ses, and in process chem­istry. His work is reflect­ed in sev­er­al patents to his name, more than one hun­dred peer-reviewed pub­li­ca­tions, and numer­ous invit­ed lec­tures and sem­i­nars span­ning India, USA, Chi­na, and Europe. His recent­ly edit­ed book: New Trends in Cross Cou­pling: The­o­ry and Appli­ca­tions by the Roy­al Soci­ety of Chem­istry is wide­ly used in acad­e­mia and indus­try. Through his work, Dr. Cola­cot is cred­it­ed with being a lead­ing influ­ence in devel­op­ing excep­tion­al cat­alyt­ic sys­tems for the advance­ment of met­al-cat­alyzed syn­thet­ic organ­ic chem­istry for real world appli­ca­tions such as drug devel­op­ment, OLED’s/liquid crys­tals and agri­cul­ture. His empha­sis in design­ing cat­a­lysts and cat­alyt­ic process­es has been on their applic­a­bil­i­ty in indus­tri­al set­tings, par­tic­u­lar­ly per­tain­ing to agri­cul­ture, elec­tron­ics and med­i­cine. He is the finest exam­ple of a link between acad­e­mia and indus­try.

Dr. Colacot’s con­tri­bu­tions to the field have result­ed in many awards and acco­lades, amongst them the recent pres­ti­gious IIT Madras 2016 Dis­tin­guished Alum­nus Award for Tech­nol­o­gy Inno­va­tions and Chem­i­cal Research Soci­ety of India (2016 CRSI) Medal for out­stand­ing con­tri­bu­tions in Organometallics and Homo­ge­neous Catal­y­sis. He is the first Indi­an to be award­ed the Amer­i­can Chem­i­cal Soci­ety (ACS) Nation­al Award in Indus­tri­al Chem­istry in 2015. He also received the 2015 IPMI Hen­ry Alfred Award (2015) from the Inter­na­tion­al Pre­cious Met­al Insti­tute, spon­sored by the BASF. In 2014 he received the Indi­an Amer­i­can Ker­ala Cul­ture and Civic Cen­ter Award for his out­stand­ing con­tri­bu­tions in Applied Sci­ences. In addi­tion, he received Roy­al Soci­ety of Chem­istry 2012 Applied Catal­y­sis Award and Medal. He is also a Fel­low of the Roy­al Soci­ety of Chem­istry, UK.

Production of para-methylstyrene and para-divinylbenzene from furanic compounds

2017 Spring Symposium

Mol­ly Koehle and Raul Lobo, Chem­i­cal and Bio­mol­e­c­u­lar Engi­neer­ing, Uni­ver­si­ty of Delaware, Newark, DE

Abstract — Of the three iso­mers of methyl­styrene, para-methyl­styrene is high­ly desir­able because it yields poly­mers with supe­ri­or prop­er­ties over poly­styrene and mixed poly-methyl­styrene [1]. How­ev­er, con­trol­ling the sub­sti­tu­tion of methyl­styrene via direct acy­la­tion or alky­la­tion of toluene is dif­fi­cult because even though the para iso­mer is favored, meta and ortho iso­mers are also formed [1, 2], and sep­a­ra­tion of the iso­mer mix­ture is very dif­fi­cult due to their near­ly iden­ti­cal prop­er­ties.

The Diels-Alder cycload­di­tion and dehy­dra­tion of sub­sti­tut­ed furans with eth­yl­ene is a plau­si­ble route to p-methyl­styrene since it is inher­ent­ly selec­tive to para aro­mat­ic species. We have suc­cess­ful­ly devel­oped a three-step cat­alyt­ic route to p-methyl­styrene from methyl­fu­ran (Scheme 1) at high yield and very high iso­mer selec­tiv­i­ty. The process uses Friedel-Crafts acy­la­tion, selec­tive reduc­tions with hydro­gen and Diels-Alder cycload­di­tion with eth­yl­ene. The raw materials—furans, eth­yl­ene and acetic acid—can all be derived from bio­mass [3,4], thus allow­ing ‘green’ styrene pro­duc­tion from renew­able car­bon sources. This approach has also been extend­ed to the pro­duc­tion of p-divinyl­ben­zene. As the acy­la­tion step is known to be cat­alyzed by Lewis acids, recent work has focused on study­ing this step on Brøn­st­ed and Lewis acid zeo­lites and will be pre­sent­ed as well.

Scheme 1: Pro­duc­tion of para-methyl­styrene from methyl­fu­ran

[1] W.W. Kaed­ing and G.C. Bar­ile, in: B.M. Cul­bert­son and C.U. Pittman, Jr. (Eds.), New Monomers and Poly­mers, Plenum Press, New York, NY, 1984, pp. 223–241.
[2]“Aromatic Sub­sti­tu­tion Reac­tions.” http://​www2​.chem​istry​.msu​.edu/​f​a​c​u​l​t​y​/​r​e​u​s​c​h​/​V​i​r​t​T​x​t​J​m​l​/​b​e​n​z​r​x​1​.​htm
[3] A.A. Rosatel­la; S.P. Sime­onov; R.F.M. Frade, R.F.M..; C.A.M. Afon­so, Green Chem., 13 (2011) 754.
[4] C.H. Chris­tensen; J. Rass-Hansen; C.C. Mars­den; E. Taarn­ing; K. Ege­blad, Chem­SusChem, 1 (2008) 283.

Biog­ra­phy — Mol­ly obtained her B.S. in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Pitts­burgh and her M.S. in Chem­i­cal Engi­neer­ing from the Uni­ver­si­ty of Con­necti­cut. She has worked at the Catal­y­sis Cen­ter for Ener­gy Inno­va­tion in Prof. Raul Lobo’s group since 2013. Her work focus­es on trans­for­ma­tions of bio­mass to fuels and chem­i­cals with Bron­st­ed and Lewis acid zeo­lites.

The mechanism of CO2 reduction over Pd/Al2O3: a combined steady state isotope transient kinetic analysis (SSITKA) and operando FTIR investigation

2017 Spring Symposium

Xiang Wang, Hui Shi and János Szanyi, Insti­tute for Inte­grat­ed Catal­y­sis, Pacif­ic North­west Nation­al Lab­o­ra­to­ry, Rich­land, WA

Abstract — Under­stand­ing the crit­i­cal steps involved in the het­ero­ge­neous cat­alyt­ic CO2 reduc­tion has attract­ed a lot of atten­tion recent­ly. In order to ful­ly under­stand the mech­a­nism of this reac­tion the deter­mi­na­tion of both the rate-deter­min­ing steps and reac­tion inter­me­di­ates are vital. Steady-State Iso­topic Tran­sient Kinet­ic Analy­sis (SSITKA) is one of the most pow­er­ful tech­niques used to inves­ti­gate the ele­men­tary steps under steady-state reac­tion con­di­tions. This tech­nique pro­vides valu­able infor­ma­tion on mean res­i­dent life­time of sur­face inter­me­di­ates, sur­face con­cen­tra­tions of adsorbed reac­tant species and an upper bound of the turnover fre­quen­cy. Cou­pling SSITKA with operan­do-FTIR spec­troscopy allows us to dis­crim­i­nate between active and spec­ta­tor species present on the cat­alyt­ic sur­face under steady state reac­tion con­di­tions.  In the present work operan­do SSITKA exper­i­ments cou­pled with trans­mis­sion FTIR, mass spec­trom­e­try (MS) and gas chro­matog­ra­phy (GC) were per­formed to probe both the chem­i­cal nature and kinet­ics of reac­tive inter­me­di­ates over a Pd-Al2O3 cat­a­lysts and pro­vide a clear mech­a­nis­tic pic­ture of the CO2 hydro­gena­tion reac­tion by reveal­ing the rate-deter­min­ing steps for CH4 and CO pro­duc­tion.

Fig­ure 1 shows nor­mal­ized real-time sig­nals for the decay and increase of methane (a) and car­bon-monox­ide (b) in the efflu­ent at 533 K reac­tion tem­per­a­ture after the feed gas was switched at 0 s from CO2/H2/Ar mix­ture to 13CO2/H2 mix­ture.  With increas­ing tem­per­a­ture, the decay of CH4 and CO get faster.  By inte­gra­tion under the decay curves , the mean sur­face-res­i­dence times CH4 and  CO), the abun­dance of adsorbed sur­face inter­me­di­ates lead­ing to CH4 and CO prod­ucts  CH4 and  CO) at 533–573 K were cal­cu­lat­ed. At low tem­per­a­ture, CO2 metha­na­tion is slow­er than the reverse water-gas shift reac­tion, but became faster as the tem­per­a­ture was increased over 563 K.  The sim­i­lar appar­ent acti­va­tion ener­gies obtained for the hydro­gena­tion of adsorbed CO and for the for­ma­tion of CH4 indi­cates that the hydro­gena­tion of CO is the rate-deter­min­ing step dur­ing the CO2 metha­na­tion reac­tion. More­over, the sim­i­lar appar­ent acti­va­tion ener­gies esti­mat­ed for the con­sump­tion of adsorbed for­mates (FTIR) and for the for­ma­tion of CO (MS), indi­cates that the H-assist­ed decom­po­si­tion of for­mates is the rate deter­min­ing step in the reverse water gas shift reac­tion.  The rate-deter­min­ing step for CO for­ma­tion is the con­ver­sion of adsorbed for­mate, while that for CH4 for­ma­tion is the hydro­gena­tion of adsorbed car­bonyl. The bal­ance of the hydro­gena­tion kinet­ics between adsorbed for­mates and car­bonyls gov­erns the selec­tiv­i­ties to CH4 and CO. We applied this knowl­edge to design cat­a­lysts and achieved high selec­tiv­i­ties to desired prod­ucts. 

Fig­ure 1. Nor­mal­ized response of (a) CH4 and 13CH4 prod­ucts and (b) CO and 13CO prod­ucts as func­tions of time.

Biog­ra­phy — Dr. Szanyi‘s research is focused on sur­face sci­ence, spec­troscopy and kinet­ic stud­ies on het­ero­ge­neous cat­alyt­ic reac­tion sys­tems aimed at under­stand­ing struc­ture-reac­tiv­i­ty rela­tion­ships. In par­tic­u­lar, he is inter­est­ed in under­stand­ing the mech­a­nis­tic con­se­quences of very high (atom­ic) met­al dis­per­sion on dif­fer­ent sup­port mate­ri­als. Using a series of ensem­ble aver­aged spec­troscopy meth­ods he inves­ti­gates the fun­da­men­tal prop­er­ties of met­al atoms and small met­al clus­ters pre­pared under well con­trolled UHV con­di­tions. These results pro­vide infor­ma­tion on the ener­get­ics of the inter­ac­tions between high­ly dis­persed met­als and select­ed probe mol­e­cules. Apply­ing in situ RAIR spec­troscopy they study the bind­ing con­fig­u­ra­tions of adsor­bates to met­als, and iden­ti­fy sur­face species present on the met­al and sup­port mate­ri­als under ele­vat­ed reac­tant pres­sures. Simul­ta­ne­ous­ly, they are con­duct­ing detailed kinet­ics and operan­do spec­troscopy mea­sure­ments on mod­el high sur­face area sup­port­ed met­al cat­a­lysts using flow reac­tors and SSITKA/FTIR/MS tech­niques. These mea­sure­ments pro­vide detailed kinet­ic infor­ma­tion togeth­er with sur­face spe­ci­a­tion that allow them to great­ly enhance our mech­a­nis­tic under­stand­ing of het­ero­ge­neous cat­alyt­ic sys­tems, in par­tic­u­lar the reduc­tion of CO2. Dr Szanyi is also involved in research relat­ed to the fun­da­men­tal under­stand­ing of auto­mo­tive emis­sion con­trol catal­y­sis, con­duct­ing research in selec­tive cat­alyt­ic reduc­tion of NOx on zeo­lite-based cat­a­lysts, low tem­per­a­ture NO and CO oxi­da­tion on met­al oxides, and low tem­per­a­tures NOx and HC stor­age in zeo­lites.

Design of complex metal/metal-oxide heterogeneous catalytic materials for energy and chemical conversion

2017 Spring Symposium

Eran­da Nikol­la, Depart­ment of Chem­i­cal Engi­neer­ing and Mate­ri­als Sci­ence, Wayne State Uni­ver­si­ty, Detroit, MI

Abstract — Dwin­dling fuel resources and high lev­els of CO2 emis­sions have increased the need for renew­able ener­gy resources and more effi­cient ener­gy con­ver­sion and stor­age sys­tems. In this talk, some of our recent work on design­ing effi­cient (active, selec­tive and sta­ble) cat­alyt­ic sys­tems for ener­gy and chem­i­cal con­ver­sions will be dis­cussed. First, I will talk about our work on design­ing lay­ered nick­e­late oxide elec­tro­cat­a­lysts for elec­tro­chem­i­cal oxy­gen reduc­tion and evo­lu­tion reac­tions. These process­es play an impor­tant role in fuel cells, elec­trolyz­ers and Li-air bat­ter­ies. We have uti­lized den­si­ty func­tion­al the­o­ry (DFT) cal­cu­la­tions to iden­ti­fy the fac­tors that gov­ern the activ­i­ty of nick­e­late oxides toward these process­es. Using a reverse microemul­sion approach we demon­strate an approach for syn­the­siz­ing nanos­truc­tured nick­e­late oxide elec­tro­cat­a­lysts with con­trolled sur­face struc­ture. These nanos­truc­tures are thor­ough­ly char­ac­ter­ized using atom­ic-res­o­lu­tion high angle annu­lar dark field (HAADF) imag­ing along with elec­tron ener­gy-loss spec­troscopy (EELS) per­formed using an aber­ra­tion cor­rect­ed scan­ning trans­mis­sion elec­tron micro­scope (STEM). Con­trolled kinet­ic iso­topic and elec­tro­chem­i­cal stud­ies are used to devel­op structure/performance rela­tion­ships to iden­ti­fy nick­e­late oxides with opti­mal elec­tro­cat­alyt­ic activ­i­ty. Sec­ond­ly, I will dis­cuss our efforts on design­ing effi­cient cat­alyt­ic sys­tems for bio­mass con­ver­sion process­es. Devel­op­ment of active and selec­tive cat­a­lysts for bio­mass con­ver­sion is crit­i­cal in real­iz­ing a renew­able plat­form for fuels and chem­i­cals. I will high­light some of our recent work on uti­liz­ing reducible met­al oxide encap­su­lat­ed noble met­al cat­alyt­ic mate­ri­als to pro­mote hydrodeoxy­gena­tion (HDO) of bio­mass-derived com­pounds. We show enhance­ment in HDO activ­i­ty and selec­tiv­i­ty due to the encap­su­la­tion of the met­al nanopar­ti­cles by an oxide film pro­vid­ing high inter­fa­cial con­tact between the met­al and met­al oxide sites, and restric­tive acces­si­ble con­for­ma­tions of aro­mat­ics on the met­al sur­face.

Biog­ra­phy — Eran­da Nikol­la is an assis­tant pro­fes­sor in the Depart­ment of Chem­i­cal Engi­neer­ing and Mate­ri­als Sci­ence at Wayne State Uni­ver­si­ty since Fall 2011. Her research inter­ests lie in the devel­op­ment of het­ero­ge­neous cat­a­lysts and elec­tro­cat­a­lysts for chem­i­cal con­ver­sion process­es and elec­tro­chem­i­cal sys­tems (i.e., fuel cells, elec­trolyz­ers) using a com­bi­na­tion of exper­i­men­tal and the­o­ret­i­cal tech­niques. Dr. Nikol­la received her Ph.D. in Chem­i­cal Engi­neer­ing from Uni­ver­si­ty of Michi­gan in 2009 work­ing with Prof. Suljo Lin­ic and Prof. Johannes Schwank in the area of sol­id-state elec­tro­catal­y­sis. She con­duct­ed a two-year post­doc­tor­al work at Cal­i­for­nia Insti­tute of Tech­nol­o­gy with Prof. Mark E. Davis pri­or to join­ing Wayne State Uni­ver­si­ty. At Cal­tech she devel­oped exper­tise in syn­the­sis and char­ac­ter­i­za­tion of meso/microporous mate­ri­als and func­tion­al­ized sur­faces. Dr. Nikol­la is the recip­i­ent of a num­ber of awards includ­ing the Nation­al Sci­ence Foun­da­tion CAREER Award, the Depart­ment of Ener­gy CAREER Award, 2016 Camille Drey­fus Teacher-Schol­ar Award and the Young Sci­en­tist Award from the Inter­na­tion­al Con­gress on Catal­y­sis.

Mechanisms and Materials for Alkaline Hydrogen Electrocatalysis

2017 Spring Symposium

Mau­reen Tang, Chem­i­cal and Bio­log­i­cal Engi­neer­ing, Drex­el Uni­ver­si­ty, Philadel­phia, PA

Abstract — Hydro­gen is a poten­tial low cost, scal­able ener­gy stor­age medi­um for renew­able elec­tric­i­ty gen­er­a­tion. More impor­tant­ly, study of the hydro­gen elec­trode reac­tions has led to the dis­cov­ery of many of the fun­da­men­tal con­cepts in elec­tro­chem­istry and elec­tro­catal­y­sis. It has long been rec­og­nized that the reac­tion rates of the hydro­gen oxi­da­tion and hydro­gen evo­lu­tion reac­tions (HOR and HER) are slow­er in basic than acidic elec­trolytes, even though the sur­face inter­me­di­ate of adsorbed hydro­gen is inde­pen­dent of solu­tion pH. Under­stand­ing the root of this obser­va­tion is crit­i­cal to design­ing cat­a­lysts for a mul­ti­tude of elec­tro­chem­i­cal reac­tions with rel­e­vance to ener­gy con­ver­sion and stor­age. In this work, we under­take both applied and fun­da­men­tal efforts to under­stand the mech­a­nisms and devel­op low-cost, active cat­a­lysts for the hydro­gen reac­tions in base.

In the first part of the talk, we uti­lize a the­o­ry-guid­ed approach to devel­op nick­el-sil­ver cat­a­lysts for alka­line hydro­gen evo­lu­tion and oxi­da­tion. Den­si­ty-func­tion­al-the­o­ry cal­cu­la­tions pre­dict these alloys will be active for hydro­gen evo­lu­tion and oxi­da­tion. To cir­cum­vent the ther­mo­dy­nam­ic insol­u­bil­i­ty of these two met­als and iso­late cat­alyt­ic activ­i­ty, we employ an uncom­mon phys­i­cal vapor code­po­si­tion syn­the­sis. Our mea­sure­ments show that the alloy is indeed more active for hydro­gen evo­lu­tion than pure nick­el. In the sec­ond part of the talk, we exam­ine specif­i­cal­ly the hypoth­e­sis that water ori­en­ta­tion gov­erns the rate of hydro­gen adsorp­tion and thus the over­all HER/HOR kinet­ics by mod­u­lat­ing the poten­tial of zero charge of oxide sup­ports in acid and base. Final­ly, we com­bine micro­ki­net­ic mod­el­ing and sin­gle-crys­tal mea­sure­ments to deter­mine if adsorbed hydrox­ide func­tions as an active inter­me­di­ate or spec­ta­tor in the reac­tion. The results of these stud­ies high­light the impor­tance of kinet­ic bar­ri­ers, as well as adsorp­tion ener­gies, and con­tribute to resolv­ing a long-stand­ing para­dox in elec­tro­catal­y­sis and sur­face sci­ence.

Biog­ra­phy — Mau­reen Tang joined the fac­ul­ty of Chem­i­cal and Bio­log­i­cal Engi­neer­ing at Drex­el Uni­ver­si­ty in Fall 2014. She received her B.S. in Chem­i­cal Engi­neer­ing from Carnegie Mel­lon Uni­ver­si­ty and her Ph. D. from the Uni­ver­si­ty of Cal­i­for­nia, Berke­ley. While at Berke­ley, she received a NSF Grad­u­ate Research Fel­low­ship, an NSF East Asia Pacif­ic Sum­mer Fel­low­ship, and the Daniel Cubi­ciot­ti Stu­dent Award of the Elec­tro­chem­i­cal Soci­ety. Dr. Tang has com­plet­ed post­doc­tor­al work at Stan­ford Uni­ver­si­ty and research intern­ships at Kyoto Uni­ver­si­ty, the Uni­ver­si­ty of Dort­mund, and Dupont. Her research at Drex­el devel­ops mate­ri­als, archi­tec­tures, and fun­da­men­tal insight for elec­tro­chem­i­cal ener­gy stor­age and con­ver­sion.