Catalytic ketonisation over oxide catalysts. Part VII. Ketonisation and cross-ketonisation of aliphatic esters over CeO2 and ZrO2 supported alumina

Catalysts of general formula x wt.% MO2/Al2O3 where x = 10, 20, or 30 and M = Ce or Zr have been studied in the ketonisation and cross-ketonisation of aliphatic esters under flow conditions between 548-723 K. Ketonisation of pentanoate, heptanoate and nonanoate has led to nonan-5-one, tridecan-7-one and heptadecan-9-one respectively. The conversion of esters increased with temperature and at 698 K a quantitative conversion was observed, irrespective of the type of ester used. A maximum yield of ketone (46% for nonan-5-one, 60% for tridecan-7-one and 50% for heptadecan-9-one) was observed at 673 K. As a result of cross-ketonisation of a mixture of ethyl pentanoate and ethyl nonanoate (3:1 molar ratio), three ketones are formed: nonan-5-one, tridecan-7-one and heptadecan-9-one. At 698 K, maximum yields of ketones were noted (37, 46 and 8%, respectively) together with 90% conversion of esters. The catalysts were characterized by XRD, TPR and surface area measurements. (author)