Catalytic ketonisation of acetic acid over modified zirconia - 1. Effect of alkali-metal cations as promoter

The catalytic ketonisation of acetic acid was studied over fifteen different metal-doped zirconia samples. Among all, the catalytic aspects of alkali-metal cation-promoted zirconia were extensively studied and found most effective for ketonisation of acetic acid. The reactions were performed in a fixed-bed reactor by varying the temperatures, flow rates of reactant and mole percent of alkali on the catalyst. Except Li, all the alkali-metal ions were capable of enhancing the catalytic activity. Complete conversion with high selectivity for acetone was observed in the temperature range of 623-698 K. Among all the alkali-metal-modified zirconia, sodium was the most effective promoter for ketonisation reaction. The observed activity order followed Na > K > Cs > Li. (C) 1999 Elsevier Science B.V. All rights reserved.