Alex Bell awarded 2003 Robert Burwell Lectureship in Catalysis

Pro­fes­sor Alex­is T. Bell has been award­ed the 2003 Robert Bur­well Lec­ture­ship in Catal­y­sis by the North Amer­i­can Catal­y­sis Soci­ety. The Lec­ture­ship is spon­sored by John­son Matthey PLC’s Cat­a­lysts and Chem­i­cals Divi­sion and is giv­en in recog­ni­tion of sub­stan­tial con­tri­bu­tions to one or more areas in the field of catal­y­sis with empha­sis on dis­cov­ery and under­stand­ing of cat­alyt­ic phe­nom­e­na, cat­alyt­ic reac­tion mech­a­nisms and iden­ti­fi­ca­tion and descrip­tion of cat­alyt­ic sites and species. His research activ­i­ties have led to more than 400 pub­li­ca­tions in the most pres­ti­gious jour­nals in catal­y­sis, chem­istry and chem­i­cal engi­neer­ing. Over many years he has applied cut­ting-edge spec­troscopy and the­o­ry to study sur­faces before and after cat­alyt­ic reac­tions.

His nom­i­na­tors offered some of the fol­low­ing remarks. His ear­li­er work with Pro­fes­sor Doros Theodor­ou pio­neered the appli­ca­tion of sta­tis­ti­cal mechan­ics and mol­e­c­u­lar dynam­ics for pre­dict­ing the adsorp­tion and dif­fu­sion of mol­e­cules in zeo­lites. This rep­re­sent­ed one of the first quan­ti­ta­tive appli­ca­tions of the­o­ret­i­cal meth­ods to sys­tems of direct cat­alyt­ic rel­e­vance. Lat­er his work with Pro­fes­sor Arup Chakraborty suc­ceed­ed in using quan­tum mechan­i­cal cal­cu­la­tions to deter­mine the sit­ing and sta­bil­i­ty of met­al cations exchanged into zeo­lites. In the area of Fis­ch­er-Trop­sch syn­the­sis, his ele­gant use of in situ infrared meth­ods, sur­face sci­ence tech­niques, and iso­topic switch meth­ods led to a mech­a­nis­tic pic­ture of “unprece­dent­ed clar­i­ty and rel­e­vance.” Rate con­stants for ele­men­tary steps and the iden­ti­ty and reac­tiv­i­ty of spe­cif­ic adsorbed inter­me­di­ates were mea­sured and ulti­mate­ly used to elu­ci­date the under­ly­ing struc­ture-func­tion rela­tions for chain growth as well as the oper­a­tive basis for wide­ly report­ed strong meta-sup­port­ed inter­ac­tions. His stud­ies have led to demon­stra­tion of a nov­el bifunc­tion­al mech­a­nism for methanol syn­the­sis and leads to strong effects of Lewis acid­i­ty and basic­i­ty of ZrO2 on activ­i­ty and selec­tiv­i­ty. He has also made sig­nif­i­cant con­tri­bu­tions in the area of zeo­lite catal­y­sis by elu­ci­dat­ing the mech­a­nism of both the syn­the­sis and func­tion of these het­ero­ge­neous cat­a­lysts.

Togeth­er with Pro­fes­sor Clay Rad­ke, the appli­ca­tion of NMR meth­ods led to the direct obser­va­tion of the struc­ture-direct­ing role of organ­ic and inor­gan­ic cations dur­ing syn­the­sis and to a clear mech­a­nis­tic pic­ture of their self-assem­bly in com­plex solu­tions and gels. A com­bi­na­tion of kinet­ic, infrared, iso­topic and the­o­ret­i­cal stud­ies also led to a clear­er mech­a­nis­tic and struc­tur­al pic­ture of the nature of exchanged cations in zeo­lites and their involve­ment in form­ing and sta­bi­liz­ing reac­tive inter­me­di­ates in the reduc­tion of NO by hydro­car­bons. In the area of met­al oxides, Alex pio­neered the use of Raman spec­troscopy for the struc­tur­al char­ac­ter­i­za­tion of dis­persed struc­tures. His appli­ca­tions of these meth­ods to the char­ac­ter­i­za­tion of oxida­tive dehy­dro­gena­tion cat­a­lysts led to spe­cif­ic assign­ments of site reac­tiv­i­ty and to a com­pre­hen­sive pic­ture of the mech­a­nism and site require­ments for desired and unde­sired reac­tions of alka­nes on dis­persed oxides. More recent­ly, work­ing in col­lab­o­ra­tion with Pro­fes­sor Enrique Igle­sia, he has also explored the use of in situ UV-vis­i­ble and X‑ray absorp­tion spec­troscopy in mea­sur­ing the num­ber of active sites and reduced cen­ters dur­ing alka­ne oxi­da­tion reac­tions. Through­out all this work, Alex has repeat­ed­ly demon­strat­ed a nat­ur­al tal­ent that allows him to trans­late his research on cat­alyt­ic phe­nom­e­na, cat­alyt­ic reac­tion mech­a­nisms, and the iden­ti­fi­ca­tion and descrip­tion of cat­alyt­ic sites for a wide range of chemistries into under­stand­able terms for his audi­ence.

The lec­ture­ship comes with an hon­o­rar­i­um and trav­el stipend that will allow him to vis­it many of the local clubs of the North Amer­i­can Catal­y­sis Soci­ety in order to stim­u­late both young and old minds to the mar­vels of catal­y­sis.
John N. Armor