(163a) Selective Hydrogenation of Alkynes to Alkenes

Selective hydrogenation of alkynes to alkenes is an important process for various industries. In this study, our investigation focuses on the effects of pretreatments, such as non-thermal plasma with various gases and reduction temperature, on supported palladium-ceria catalysts for liquid-phase semi-hydrogenation of ethyl phenylpropiolate at room temperature. The current results from different reduction temperatures show that the activity order is 400°C ~ 500°C > 300°C > 600°C while the selectivity order is 600°C > 500°C ~ 300°C > 400°C. Overall, with 500°C reduction, its yield of cis ethyl cinnamate is the highest of 90.9% at 30-min of reaction time.

It is interesting that the reduction temperature and plasma treatments are both critical to the performance of catalysts. This is likely due to the strong interaction between Pd and ceria after pre-treatments. The detailed surface and bulk properties of PdCeOx will be investigated by pulse chemisorption and temperature programmed techniques.