Selective esterification of tert-butanol by acetic acid anhydride over clay supported InCl3, GaCl3, FeCl3 and InCl2 catalysts

Clay (kaolin, mont-K10 and mont-KSF) supported InCl 3 , GaCl 3 , FeCl 3 and ZnCl 2 catalysts (metal chloride loading=1.1 mmol g −1 ) show high selectivity (⩾98%) at high conversion in the esterification of tert-butanol by acetic anhydride to tert-butyl acetate ( t -BA) and very low activity for the dehydration of tert-butanol at ⩽50°C. For all the catalysts, mont-K10 is the best support and the order of their esterification activity (at 26°C) is: InCl 3 /mont-K10 (TOF=0.025 s −1 ) > GaCl 3 /mont-K10 (0.023 s −1 ) > FeCl 3 /mont-K10 (0.02 s −1 ) ⩾ ZnCl 2 /mont-K10 (0.019 s −1 ). InCl 3 /mont-K10 is highly active, selective and reusable catalyst for the esterification.