Silication of γ-alumina catalyst during the dehydration of linear primary alcohols

摘要: Abstract The dehydration of alcohols to alkenes over heterogeneous catalysts such as γ-alumina occurs at temperatures around 300 °C, and it could be accompanied by undesirable reactions double-bond shift and, in severe cases, skeletal isomerization the alkene products. In 1-hexanol 1-octanol (separately) γ-alumina, we found that selectivity 1-alkenes decreased substantially with time-on-stream (TOS), while alcohol conversion remained virtually constant. loss 1-alkene is a result an increase extent increasing TOS. Upon analysis (fresh used) feeds (all ICP spectroscopy), was contained on average 1 ppm silicon content used high 15 times fresh one (3000 ppm compared 200 ppm, our examples). results show, therefore, there accumulation catalyst during reaction this leads formation additional stronger acid sites, those silicated aluminas, which account for activity catalyst.