Thermolytic Molecular Precursor Route to Site-IsolatedVanadia-Silica Materials and Their Catalytic Performance in MethaneSelective Oxidation

Journal Article · Wed Nov 23 04:00:00 EST 2005 · Journal of Catalysis

OSTI ID:919832

Ruddy, Daniel A; Ohler, Nicholas L; Bell, Alexis T; Tilley, T Don

The thermolytic molecular precursor (TMP) method was used to prepare site-isolated, high-surface area vanadia-silica (V/SBA15) materials of various V loadings via the grafting of two precursors, OV[OSi(O{sup t}Bu){sub 3}]{sub 3} (1) and Ov(O{sup t}Bu){sub 3} (2). Spectroscopic analysis indicates that excellent synthetic control was established for the exclusive formation of a pseudotetrahedral monovanadate (VO4) structure on all catalyst surfaces. Another V/SBA15 catalyst was prepared via conventional incipient wetness impregnation (WI) with aqueous NH4VO3. A spectroscopic investigation of this catalyst revealed the presence of monovanadate and polyvanadate species along with small domains of V2O5. The TMP materials behave as single-site catalysts in the selective oxidation of methane to formaldehyde up to a V coverage of 0.47 Vnm-2 and demonstrate superior activity compared with the WI catalyst. A space-time yield of 5.84 kgCH2Okg-1cat h-1 was observed, more than twice the highest value previously reported.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Basic EnergySciences
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 919832
• Report Number(s): LBNL--59613; BnR: KC0302010
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Vol. 238; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CATALYSTS
FORMALDEHYDE
IMPREGNATION
METHANE
OXIDATION
PERFORMANCE
PRECURSOR