Industrialized Study Of Pd/C Catalyst And Its Applying In Catalytic Transfer Hydrogenation

In our study, the parameter of preparation Pd/C catalyst was confirmed by selecting the hydrogenation of acetophenone and benzenecarboxylic acid as probe reaction. Types of surported material and its pretreatment, concentration and PH value of precursor, adsorption temperature and time, reduction temperature and time and other factors on the activity of catalysts were systematicly studied . In contrast with domestic and imported catalysts,catalysts as synthsized, either 5% of palladium or 10% of palladium both showed higher activity than similar domestic and imported catalysts respectively.In the same react condition, using 5% Pd/C catalyst as synthsized, the hydrogenation conversion of benzenecarboxylic acid was 40.34% , which was 1.87times than domestic catalyst and 1.42 times than American catalyst. Using 10% Pd/C catalyst as synthsized, the conversion hydrogenation conversion of benzenecarboxylic acid was 77.78%, which was 1.64 times than than American catalyst.Compared with American 10% Pd/C catalyst, the as synthesized 10% catalyst showed longer catalytic lifetime obviously . The activity of as synthesized 10% catalyst skipped after five times' use which happened only after one times' use for American 10% catalyst. The value of press descent of as synthesized 10% catalyst was 0.45Mpa after 17 times'use while the value of press descent of American 10% catalyst was 0.4Mpa after 11 times'use.After laboratory experiment, the preparation process was enlarged to kilograms level. The product were sent to three domestic pharmaceutical plants for evaluation. Compared our product with the catalysts which they use at present, as synthesized product was superior to those catalysts in activity and lifetime.The surported material was changed to carbon nanotubes, and Pd/CNTs catalyst was prepared through the same method and was used in the heterogeneous catalytic transfer hydrogenation of acetophenone. Catalytic transfer hydrogenation is commonly used in organic synthesis as a means of hydrogenation. The hydrogen source is not the hydrogen gas but some other chemical substances containing hydrogen atoms. Compared with the hydrogen gas hydrogenation process, it has more advantages such as higher security, lower temperature, lower requirements of equipment and so on. Meanwhile, it supplied a new way to increase the selectivity in the process of catalitic transfer hydrogenation because of its diversity of hydrogen sources.In this paper, a new system of heterogeneous catalytic transfer hydrogenation was found. In the process, secondary butyl alcohol was hydrogen donor as well as solvent, Pd/CNTs was catalyst, and sodium hydroxide was assistant catalyst. It showed a high activity for the hydrogenation of acetophenone, the yield of acetophenonol reached 96% in 10 hours.