Synthesis and characterization of pure STW-zeotype germanosilicate, Cu- and Co-substituted STW-zeotype materials

Journal Article · Fri May 15 00:00:00 EDT 2015 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2014.12.031· OSTI ID:22475604

Zhang, Na ^[1]; Shi, Lei ^[1]; Yu, Tingting ^[1]; Li, Tianduo ^[1]; Hua, Wei; Lin, Cong ^[2]

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1. Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China)
2. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

Pure STW-type germanosilicate (denoted as GeSi-STW), Cu- and Co-containing STW-zeotype (denoted as Cu-STW and Co-STW) materials were synthesized by the hydrothermal method in the presence of an organic structure-directing agent (OSDA), N,N-diethylethylenediamine (DEEDA). The effects of the reaction mixture ratio and the incorporation of transition metals M (M=Cu and Co) on the synthesis of the pure product was investigated. The synthesized samples were characterized by powder and single-crystal X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma analysis (ICP), thermogravimetric and differential scanning calorimetry (TG–DSC) analysis and UV–vis diffuse reflectance spectra (DRS). The results reveal that the crystallization time, the concentration of H{sub 2}O in the reaction mixture and the addition of HF all have an important impact on the synthesis of pure STW-type zeolite. GeSi-STW is stable up to 800 °C, and has much higher thermal stability than SU-32 (stable to 400 °C). Co and Cu have been introduced for the first time into STW-zeotype materials. - Graphical abstract: SEM images of GeSi-STW (A and B), Co-STW (C and D) and Cu-STW (E and F). - Highlights: • Pure STW-type germanosilicate materials were hydrothermally synthesized. • The STW-type germanosilicate has high thermal stability up to 800 °C. • Co and Cu have been introduced for the first time in the STW-zeotype materials.

• OSTI ID: 22475604
• Journal Information: Journal of Solid State Chemistry, Vol. 225; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMINES
CALORIMETRY
COBALT COMPOUNDS
CONCENTRATION RATIO
COPPER COMPOUNDS
CRYSTALLIZATION
GERMANIUM SILICIDES
HYDROFLUORIC ACID
HYDROTHERMAL SYNTHESIS
MONOCRYSTALS
POWDERS
SCANNING ELECTRON MICROSCOPY
SPECTRAL REFLECTANCE
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION
ZEOLITES