Palladium Supported on Carbon Nanotubes Decorated Nickel Foam as the Catalytic Stirrer in Heterogeneous Hydrogenation of Polystyrene

Carbon nanotubes supported palladium (Pd/CNTs) catalyst displayed excellent activity toward hydrogenation of polystyrene (PS) to produce polycyclohexylethylene (PCHE) with added commercial values. However, its application is limited by the costly catalyst filtration process and energy-consuming elevated agitation speed. Herein, a dense, homogeneous and strongly attached layer of CNTs was decorated on nickel foams and employed as the catalyst support for palladium nanoparticles. Structured catalyst (Pd/CNTs@NF) was directly used as the catalyst stirrer in a rotating foam stirrer reactor (RFSR) for PS hydrogenation. Owing to the enhanced mass-transfer process, the hydrogenation degree reached 68.8%, which was 45.1% higher than that obtained in a slurry reactor using powdered Pd/CNTs catalyst under identical reaction conditions. Outstanding attachment strength of CNTs on the foam and catalytic stability in eight runs of recycling were also demonstrated. This work elucidates the promising feasibility of structured Pd/CNTs@NF catalyst as the catalytic stirrer in RFSR.