Preparation of Pd/Al₂O₃/Nickel Microfoam Catalysts by Electrodeposition for Hydrogenation in a Micropacked Bed Reactor

In this study, an electrodeposition (ED) method is developed to prepare Pd/Al2O3/nickel microfoam (NMF) monolithic catalysts, which are used for hydrogenation in micropacked beds (MPBs). Compared with the sol-gel slurry circulation (SC) method, the ED method has a lower coating weight and smaller specific surface area but better uniformity for the coatings. The distribution of the coatings by ED and the active component Pd shows little difference between the outer and inner surfaces of NMFs. Because of the good uniformity, the catalysts by ED exhibit higher activity and stability in the hydrogenation of α-methylstyrene than those by SC. The overall external mass transfer performance of the catalysts is also evaluated, showing that the mass transfer performance is affected by the catalyst uniformity. The catalysts by this simple, fast, and cheap ED method can effectively enhance the hydrogenation and mass transfer performance in MPBs.