Thermogravimetric Evidence of Nickel or Copper Isomorphously Substituted into a Zeolite.
Abstract
The synthesis of pure silica ZSM-5 has been modified to produce highly crystalline material in the protonated form, necessary for catalytic activity, directly from a low water fluoride gel. Tetrahedrally co-ordinated divalent species of nickel and copper have been synthesised as salts of large organic cations and increasing mole fractions incorporated into the zeolite gels. The products have been analysed and characterised using simultaneous thermogravimetric and derivative thermogravimetric analysis (TG-DTG). The thermal decomposition under nitrogen of the metal associated cations, tetraethylammonium (TEA+), occluded within the zeolite channels is indicative and characteristic of the incorporation of heteroatoms into the zeolite framework. Anomalous losses in the systems can be explained by Jahn–Teller distortions. The mass losses increased with increased metal loading and were consistent with those reported in full water system, analysis also confirmed that the material was hydrophobic and thermally stable. Analysis by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR) and Atomic Absorption Spectroscopy (AAS) has confirmed the reliability of TG-DTG as a diagnostic tool. The maximum levels of substitution achieved were (mass%) Ni 3.93 and Cu 4.38.Citation
Journal of Thermal Analysis and Calorimetry, 63(2): 329-338Publisher
SpringerLinkJournal
Journal of Thermal Analysis and CalorimetryAdditional Links
https://link.springer.com/article/10.1023%2FA%3A1010133822423Type
Journal articleLanguage
enISSN
1418287415728943
ae974a485f413a2113503eed53cd6c53
10.1023/A:1010133822423