Synthesis and characterization of boron modified alumina catalyst for ethanol dehydration to ethylene

Abstract

Alumina catalyst is interesting due to its excellent thermal stability, high surface area and fine particle size. In this research, the alumina catalysts having different phases were synthesized by the solvothermal method. This method possesses high crystallinity, high surface area and uniform morphology. When γ-phase alumina is adjusted with χ-phase alumina, it results in the improvement of catalyst acidity. So, the mixed phase alumina gave the highest ethanol conversion. Ethylene production from ethanol dehydration reaction requires solid acid catalysts consisting of Brønsted acid site on surface. Acidity of alumina catalyst affected on dehydration activity. To improve catalyst acidity, it can be modified by boron loading. In this research, we investigated the effect of alumina catalysts with boron modification on ethanol dehydration. All samples were characterized by XRD, FTIR, N2 physisorption, SEM, TEM and NH3-TPD analysis. The alumina catalyst containing 2wt% boron content gave more weak acid sites, which is good for ethanol dehydration. When boron was introduced into γ-χ Al2O3 catalyst, at temperature 400°C, the catalyst gave a complete conversion. Besides, the stability of catalysts was investigated at 400°C for 72 hours.