Synthesis and Characterization of V-MCM-41 and V-SBA-15 Catalysts for C-1 Hydrocarbon Oxidation

2009 Spring Symposium

 
Gary Haller
Depart­ment of Chem­istry
Yale Uni­ver­si­ty
New Haven, CT


Abstract — Mobil com­po­si­tion of mate­r­i­al No. 41 (MCM-41) was dis­closed in 1992 and short­ly after a research project was ini­ti­at­ed at Yale to use these mate­ri­als to demon­strate a radius of cur­va­ture effect on cat­alyt­ic activ­i­ty. The “radius of cur­va­ture” effect implies a change in the sol­id sur­face ten­sion of the pore wall as the pore diam­e­ter (cur­va­ture) is changed that is expect­ed to change the activity/selectivity of an iso­lat­ed cat­alyt­ic site on the pore wall of the sup­port. An iso­lat­ed site can be formed by iso­mor­phous sub­sti­tu­tion (dur­ing syn­the­sis) of some Si cations by V cations in the MCM-41 sil­i­ca matrix. Sev­er­al labs have report­ed that iso­lat­ed V sites on a sil­i­ca sup­port are prefer­able to dimers, oligomers or poly­mers of van­dia on a sil­i­ca sup­port for the oxi­da­tion of methanol to formalde­hyde. MCM-41 might have an advan­tage rel­a­tive to oth­er sil­i­cas because of its very high sur­face area, >1000 m2/g. Both the air oxi­da­tion of methanol and methane to formalde­hyde have been used as probe reac­tions for cat­alyt­ic char­ac­ter­i­za­tion of V-MCM-41. SBA-15 has a sim­i­lar struc­ture to MCM-41, but larg­er pores and thick­er walls. Iso­mor­phous sub­sti­tu­tion of V dur­ing syn­the­sis is not prac­ti­cal, but well dis­persed V can be pre­pared post-syn­the­sis by graft­ing (reac­tion with sur­face hydrox­yls). The activ­i­ty for methanol oxi­da­tion on V-MCM-41 and V-SBA-15 will be com­pared and dis­cussed.

Speaker’s Biog­ra­phy — Gary L. Haller is the Hen­ry Pren­tiss Bec­ton Pro­fes­sor of Engi­neer­ing and Applied Sci­ence at Yale Uni­ver­si­ty with joint appoint­ments in the Depart­ments of Chem­i­cal Engi­neer­ing and Chem­istry. Pro­fes­sor Haller received a B.S. in math­e­mat­ics and chem­istry from the Uni­ver­si­ty of Nebras­ka at Kear­ney in 1962 and a Ph.D. in phys­i­cal chem­istry from North­west­ern Uni­ver­si­ty in 1966. Fol­low­ing a NATO Post-doc­tor­al Fel­low­ship at Oxford Uni­ver­si­ty, he joined the fac­ul­ty of Yale where he has held a vari­ety of admin­is­tra­tive posts that include Chair of the Depart­ment of Chem­i­cal Engi­neer­ing, Chair of the Coun­cil of Engi­neer­ing, and Deputy Provost for Phys­i­cal Sci­ences and Engi­neer­ing. He was Mas­ter of Jonathan Edwards Col­lege, one of twelve res­i­den­tial col­leges that com­prise Yale Col­lege 1997–2008.

Pro­fes­sor Haller’s research involved the mol­e­c­u­lar under­stand­ing of het­ero­ge­neous cat­a­lysts. His research com­bines the inor­gan­ic chem­istry of cat­a­lyst syn­the­sis, phys­i­cal chem­istry of spec­tro­scop­ic char­ac­ter­i­za­tion of het­ero­ge­neous cat­a­lysts, and the kinet­ics and mech­a­nism of sim­ple organ­ic reac­tions. Cur­rent research is focused on cat­a­lysts for the syn­the­sis of sin­gle walled car­bon nan­otubes and the appli­ca­tion of these car­bon nan­otubes as sup­ports for nov­el cat­alyt­ic reac­tions such as aque­ous phase reform­ing (a route to renew­able ener­gy sources).