The selective hydrogenation of propyne over copper powder and various supported copper catalysts has been examined in a dynamic flow system. Increased hydrogenation activities were found for supported copper catalysts, where for example, the turnover frequency over an ion-exchanged Cu/SiO2 catalyst was 3.5·10-2 s-1 at 140°C as compared to 1.1·10-3 s-1 over unsupported copper powder. The increased selectivity to propene with increasing temperature was found to be a general property of all copper catalysts. However, the exact pattern of activity and selectivity was found to depend upon the particular supported copper system. Deactivation was found to depend on the acidity of the support and the dispersion of copper. Overall, the most active and selective catalysts that deactivate least were copper on silica prepared by the ion-exchange technique and copper on magnesia.
- propyne hydrogenation
- support effects