Nano BEA zeolite catalysts for the selective catalytic cracking of n-dodecane to light olefins

Nano BEA zeolite catalysts were synthesized and modified by desilication and then ion-exchanged with Co. The desilication was carried out using 0.1 M of NaOH. The synthesized and modified nano BEA catalysts were characterized via different characterization techniques. Ammonia temperature program desorption (NH3-TPD) and the pyridine Fourier transform infrared (pyridine-FTIR) were utilized to investigate the acidity of catalysts. X-ray diffraction (XRD), Al-27 and Si-29 nuclear magnetic resonance (NMR) spectroscopy techniques were used to examine the structure of the catalysts. The XRD patterns of the as-synthesized nano BEA catalysts were identical to that of the reference, while the NMR analysis revealed the distribution of silicon and aluminum in the BEA structure. The scanning electron microscope (SEM) analysis confirmed that the fabricated catalysts were less than 100 nm. The desilication and Co ion-exchange altered the acidity of the catalyst. The catalysts were evaluated in the cracking of sssssss to light olefins in the temperature range from 400 degrees C to 600 degrees C. The conversion increased with the increase in the reaction temperature for both catalysts; the conversion was above 90% for the Co-BEA catalyst at a temperature above 450 degrees C. The yield of light olefins also increased at higher temperatures for both catalysts, while at a lower temperature the yield to light olefins was ca. 40% over that of Co-BEA.

Automated summary

Nano BEA zeolite catalysts were synthesized and modified by desilication and Co ion-exchange, altering the acidity of the catalysts. The conversion and yield of light olefins increased with higher reaction temperatures in the range of 400 to 600 degrees Celsius.