Dehydration of Long-chain n-Alcohols to Linear α-Olefins using Sodium Modified γ-Al2O3

Linear α-olefins (C8-C12 α-olefin, LAOs) are acknowledged as high-value added chemicals in both lubricant production and polyolefin industry. An alternative route to synthesis high-purity LAOs is the dehydration of linear long-chain n-alcohols, whereas elevating the activity and selectivity of catalysts remain a challenge. Herein we presented that using sodium-modified γ-Al2O3 as the catalyst, a high selectivity (up to 96.87%) to 1-decene was achieved, and an optimized experimental condition (329 oC and 0.25 h-1) was found using the response surface method. Characterization results including XRD, BET, Py-IR, NH3-TPD and CO2-TPD showed that a suitable ratio (~0.4 wt%) of sodium impregnating could inhibit the strong acid sites of catalyst, and sodium led to the formation of additional base sites, which accounted for the synergistic effect with other acid sites to promote the further conversion of ethers to olefins. This work is of significance for the synthesis of LAOs from long-chain n-alcohols.