Ethanol upgrading via alkali-exchanged KL-zeolite: Unravelling catalytic behavior, reaction mechanism and thermodynamic effects.

Catalysts based on KL-zeolite exchanged with alkali metal ions (Rb+ and Cs+) were studied for conversion of ethanol to oligomerization through the Guerbet reaction pathway. The catalysts were characterized by techniques such as ICP-AES, FESEM-EDX, N2-adsorption-desorption, and CO2-TPD to assess their physio-chemical properties. Effects of operating parameters, namely reaction temperature, pressure, and feed flow rate on catalytic activity for the conversion of ethanol to n-butanol were examined. Furthermore, influence of alkali metal loading on KL-zeolite was explored. Substantial ethanol conversion (42.6%) and n-butanol yield (13.9%) were achieved at 450°C and 30 kg/cm2 after a 6 h reaction employing Cs-KL zeolite catalyst. Observations indicated that the butanol selectivity is highest among the reported literature. Additionally, this catalyst has exhibited low deactivation rate attributable to coke formation. Spent catalysts were studied for XRD and DTG/TGA analysis. Present investigation establishes that KL-zeolite, particularly when modified with alkali metal ions, proves to be an efficient catalyst for the Guerbet conversion of ethanol, highlighting its potential for ethanol upgrading. [ABSTRACT FROM AUTHOR]