Synthesis and NMR characterization of SAPO-35 from non-aqueous systems using hexamethyleneimine template

Journal Article · Tue Jul 12 04:00:00 EDT 2005 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2005.03.008· OSTI ID:20889797

Venkatathri, N ^[1]

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1. Catalysis Division, National Chemical Laboratory, Pune 411 008 (India)

SAPO-35 was synthesized using hexamethyleneimine template in non-aqueous systems. X-ray diffraction and scanning electron micrograph analysis shows the synthesized sample is pure and well crystalline. Presence of four stages (1.6%, 0.8%, 7.8% and 8.4%) of weight loss is observed by TG/DTA analysis. FT-IR analysis in the framework region shows the presence of tetrahedral T-O-T vibrations is similar to the other known aluminophosphate molecular sieves. FT-IR spectrum in the -OH region shows stretching vibrations at 3631, 3604 and 3580 cm{sup -1} can be assigned to OH groups in bigger cages near S6R, in bigger cages near D6R and those actually confined inside the D6R, respectively. The spectra for the as-synthesized sample show a single symmetrical {sup 27}Al MAS NMR line at {delta} = 36.26 indicating the presence of a single tetrahedral aluminium species. Where as {sup 29}Si and {sup 31}P MAS NMR shows the presence of two peaks in both at (-89.9 and -95.15 ppm) and (-34.01 and -40.45 ppm) due to the Si substitution of P present in two different locations in double 6 ring (D6R) and in single 6 ring (S6R). {sup 27}Al 3Q-MAS NMR shows two peaks for environmentally different tetrahedral aluminium atoms. This is the first time we are showing such a fact which is not observable using ordinary MAS NMR.

• OSTI ID: 20889797
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 7 Vol. 40; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ALUMINIUM 27
CHEMICAL PREPARATION
DIFFERENTIAL THERMAL ANALYSIS
ELECTRON SCANNING
FOURIER TRANSFORMATION
INFRARED SPECTRA
MOLECULAR SIEVES
NUCLEAR MAGNETIC RESONANCE
PHOSPHORUS 31
RINGS
SILICON 29
X-RAY DIFFRACTION