Papers by Keyword: ETS-4

Abstract: Titanosilicate ETS-4 with the Sr and Ni cations modification were prepared by hydrotherrmal method using titanium trichloride and tetraethoxysilane as raw materials. The properties and morphology of the materials were characterized by XRD, SEM techniques, Sr and Ni introduced to the molecular sieve affected the frame contraction when they were heated, and did little effect on the crystallization and morphology. N₂ and CH₄ isotherms of each sample were measured at room temperature. The Sr and Ni doping could improve the N₂ and CH₄ adsorption capacities of ETS-4. The capacities of the two gases increased in the pressurization process for ETS-4-Sr and ETS-4-Ni, with the pressure increasing, no significant change in capacities of N₂ and CH₄ was observed over the ETS-4 sample. Compared to ETS-4 molecular sieves, the capacity for N₂ of ETS-4-Sr and ETS-4-Ni at the pressure of 1200 mmHg increased 4.2 and 3.9 times, respectively. At last, the results indicated that the cations doping (Sr²⁺ and Ni²⁺) can improve the adsorption performance of ETS-4 greatly.

Abstract: ETS-4 with a Si:Ti ratio of 10:1 has been successfully synthesized in our laboratory and its characterization was done using X-ray diffraction (XRD) and scanning electron microscope (SEM). The thermal behavior was studied by thermogravimetric analysis (TGA). The synthesized crystals were pelletized under high pressure without any binder. Thus the pellets have a bidispersed pore structure – intracrystalline macropores and crystal micropores of the order of 0.4 nanometers. Equilibrium isotherms of oxygen, nitrogen and methane on the ETS-4 sample were measured volumetrically. The capacity compares favorably with that of a commercially available adsorbent of similar pore size. Langmuir isotherm fits well to the experimental equilibrium data.