@article { ISI:000241320000007, title = {Synthesis and characterization of high silica content silicoaluminophosphate SAPO-35 from non-aqueous medium}, journal = {Catalysis Communications}, volume = {7}, number = {10}, year = {2006}, month = {OCT}, pages = {773-777}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

SAPO-35 with up to 15.6 Si atoms per unit cell have been synthesized, using hexamethyleneimine as template in ethylene glycol medium (molar ratio of silica in the reaction gets up to 2.5). Crystallinity and silicon incorporation was confirmed by XRD, XRF, TG/DTA, SEM, FT-IR and Al-27 and Si-29 MASNMR. These SAPO-35 materials with high Si concentration show higher activity for methanol to olefin reaction than samples prepared with up to 0.3 molar ratio of silica in the get. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {ammonia adsorption, FT-IR, MASNMR, methanol to olefin, non-aqueous medium, SAPO-35, SEM, TG/DTA, XRD}, issn = {1566-7367}, doi = {10.1016/j.catcom.2005.10.014}, author = {Venkatathri, N.} } @article { ISI:000242793800020, title = {Synthesis and characterization of TAPO-31 molecular sieves using tripropylamine template}, journal = {Catalysis Communications}, volume = {7}, number = {12}, year = {2006}, month = {DEC}, pages = {1015-1021}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

TAPO-31 was synthesized hydrothermally using a novel template tri-n-propylamine for the first time. C and N analysis shows the butanol from titanium tetrabutoxide plays an important role in the synthesis. The incorporation of titanium into framework of phosphorous and both aluminiurn and phosphorous sites was suggested from elemental analysis. Isomorphous substitution of titanium (III) in AlPO framework was confirmed from ESR and (31)p MASNMR spectra. UV-Vis and XPS spectra revealed a partial oxidation of framework titanium (III) into titanium (IV) in the calcined TAPO-31 and thus the presence of redox centers in the products. The higher titanium content (Al/Ti = 10) TAPO-31 sample shows higher activity for phenol hydroxylation compared to lower titanium content (Al/Ti = 20) and Titanium impregnated AIPO(4)-31. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {ESR, FT-IR, MASNMR, SEM, TAPO-31, TG/DTA, tripropylamine, UV-Vis, XPS, XRD}, issn = {1566-7367}, doi = {10.1016/j.catcom.2006.05.010}, author = {Venkatathri, N. and Shetty, V. N.} } @article { ISI:000242775700046, title = {Synthesis and MASNMR characterization of VPI-5 molecular sieve}, journal = {Asian Journal of Chemsitry}, volume = {19}, number = {1}, year = {2007}, month = {FEB}, pages = {347-353}, publisher = {ASIAN JOURNAL OF CHEMISTRY}, type = {Article}, address = {11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA}, abstract = {

The synthesized VPI-5 sample was characterized by XRD, SEM, FTIR, TG/DTA, Al-27, P-31 and 3Q MASNMR techniques, which shows that the sample was highly crystalline. Carbon and nitrogen analysis reveals that the sample contains no template molecules; however, TG/DTA analysis shows the presence of physisorbed template molecules. MASNMR results show the presence of two different types of aluminium and phosphorus, 3Q MASNMR shows the presence of two types of environmentally different tetrahedral aluminium, which are not observable by ordinary MASNMR along with known octahedral aluminium.

}, keywords = {3Q-MASNMR, FTIR, MASNMR, SEM, synthesis, TG/DTA, VPI-5, XRD}, issn = {0970-7077}, author = {Venkatathri, N.} }