Selective and scalable catalytic dehydration of primary alcohols to linear alpha-olefins over CeO2-doped Al2O3

Abstract

Catalytic dehydration of primary alcohols has been developed for selective and sustainable linear alpha-olefins (LAOs) production. While Al2O3-based catalysts with tunable Lewis acidity and thermal stability have shown promise in enhancing LAO selectivity, challenges like acidity loss and compromised selectivity persist. This study addresses the need for an efficient catalyst system, synthesizing CeO2-doped Al2O3 catalysts with varying Ce loading and assessing their performance in the dehydration of 1-hexanol. Characterization using various techniques revealed that 10 wt% CeO2–Al2O3 (10CA) catalyst exhibited the highest 1-hexene yield (88.1%) under optimized conditions. CeO2 doping enhanced both acidic and basic strength, with excess Ce (>15%) leading to acidity and basicity loss. The 10CA catalyst demonstrated effectiveness across alcohols of different chain lengths (C5 and C8) at varying temperatures, showcasing the impact of carbon chain length on product selectivity. The scalability of the process was explored, with the 10CA catalyst successfully applied from lab-scale (0.0072 L/day) to bench-scale (4.33 L/day) reactions. The bench-scale reaction yielded 79.9% 1-hexene with 90.5% conversion of 1-hexanol and 88.2% selectivity for 1-hexene. The successful scale-up of the catalytic dehydration process using the 10CA catalyst underscores its potential as a pivotal component in the green economy, promoting sustainability and environmental friendliness in producing LAO.