TY - JOUR
T1 - The targeted synthesis of single site vanadyl species on the surface and in the framework of silicate building block materials
AU - Lee, Ming Yung
AU - Jiao, Jian
AU - Mayes, Richard
AU - Hagaman, Edward
AU - Barnes, Craig E.
PY - 2011/2/2
Y1 - 2011/2/2
N2 - A new synthetic methodology for the targeted preparation of single site, atomically dispersed vanadyl groups in silicate matrices is described. This methodology requires functionalized silicate building blocks Si 8O20(OSnMe3)8 that become linked together through vanadyl (≡VO) groups in the matrix. A sequential addition strategy is illustrated which allows the targeting of specific connectivities for the vanadyl group to the silicate building block matrix (i.e. the number of V-O-Si bonds linking the vanadyl unit). Silicate matrices containing exclusively 3-connected (OV(OSicube)3), 2-connected (OV(OR)(OSi cube)2) or 1-connected (OVCl2(OSi cube)) vanadyl sites are described and characterized via a wide variety spectroscopic and physical techniques (gravimetric analysis, EXAFS, AA and solid state NMR (51V, 29Si, and 17O)). We demonstrate how the combination of gravimetric, solid state NMR (SSNMR) and EXAFS data can be used to uniquely define the vanadyl sites in these matrices. Furthermore, the use of 17O SSNMR (1D and MQMAS) is illustrated as an indirect spectroscopic probe to follow changes in the ligands bound to vanadium atom within the vanadyl groups in these matrices.
AB - A new synthetic methodology for the targeted preparation of single site, atomically dispersed vanadyl groups in silicate matrices is described. This methodology requires functionalized silicate building blocks Si 8O20(OSnMe3)8 that become linked together through vanadyl (≡VO) groups in the matrix. A sequential addition strategy is illustrated which allows the targeting of specific connectivities for the vanadyl group to the silicate building block matrix (i.e. the number of V-O-Si bonds linking the vanadyl unit). Silicate matrices containing exclusively 3-connected (OV(OSicube)3), 2-connected (OV(OR)(OSi cube)2) or 1-connected (OVCl2(OSi cube)) vanadyl sites are described and characterized via a wide variety spectroscopic and physical techniques (gravimetric analysis, EXAFS, AA and solid state NMR (51V, 29Si, and 17O)). We demonstrate how the combination of gravimetric, solid state NMR (SSNMR) and EXAFS data can be used to uniquely define the vanadyl sites in these matrices. Furthermore, the use of 17O SSNMR (1D and MQMAS) is illustrated as an indirect spectroscopic probe to follow changes in the ligands bound to vanadium atom within the vanadyl groups in these matrices.
KW - Building block
KW - Nanostructured solids
KW - Orthovanadate on silica
KW - Single site catalysts
KW - Vanadyl
UR - http://www.scopus.com/inward/record.url?scp=78951491186&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2010.06.029
DO - 10.1016/j.cattod.2010.06.029
M3 - Article
AN - SCOPUS:78951491186
SN - 0920-5861
VL - 160
SP - 153
EP - 164
JO - Catalysis Today
JF - Catalysis Today
IS - 1
ER -