چكيده به لاتين
In the present dissertation, the synthesis and study of microstructure and physical properties of active aluminas used in catalysts and the effect of two additives containing Ba and Sr, both separately and mixed in different percentages have been investigated. To study the samples, X-ray diffraction (XRD) analysis, and Fourier transition infrared analysis (FTIR) were used and to determine the thermal behavior of the samples, thermal STA analysis was used. In addition, the microstructure of the samples was measured using a scanning electron microscope (SEM) and the specific surface area was measured using BET.Samples 100A, 1B99A and 1S99A were selected as optimal samples for further studies due to the high percentage of gamma alumina. According to the XRD results, barium and strontium-containing effluents increased the thermal stability of Phasgama alumina, while in the sample without additive 100A, only the alumina alpha phase was detected after calcination at 1200 ° C. Significant amounts of gamma alumina phase along with alpha alumina phase were detected in samples with 1% barium and strontium additive.According to the results of FT-IR, in the raw samples bands related to Al-OH vibrations in bohemite and bands related to Al-O were identified and after calcination bands related to bohemite phase were not seen and only Al-O bands in gamma Alumina were identified. Electron microscopic images showed gibsite, bohemite, and diaspore phases in the raw samples, which, after calcination, formed the gamma alumina and alpha alumina phases with porosity. The specific surface area of the sample without additive 100A was measured as 100.1 (m2.g-1) and increased to 61.52 and (m2.g-1) 135.32, respectively, in samples with barium and strontium additives. .
