Nitrile Butadiene Rubber Hydrogenation over a Monolithic Pd/CNTs@Nickel Foam Catalysts: Tunable CNTs Morphology Effect on Catalytic Performance

In heterogeneous catalyst systems, catalytic performance was often negatively influenced by mass transfer limitations in which macromolecular reactants cannot diffuse into the inner pores to attach active sites. Carbon nanotubes (CNTs) with no-porous structure were the promising supports to solve the problem. In this work,CNTs were directly prepared by the CVD (chemical vapor deposition) method on nickel foam (NF). The morphology of the as-synthesized CNTs were effectively tailored by varying temperature for growing CNTs. The prepared CNTs composites (CNTs@NF) with good mechanical strength were employed as a palladium catalyst (Pd/CNTs@NF) for nitrile butadiene rubber (NBR) hydrogenation, where a high degree of hydrogenation (HD) was accomplished via Pd/CNTs@NF catalyst. The HD for fifth reuse was only slightly reduced, demonstrating its great recyclable activity. Remarkably, the structured Pd/CNTs@NF catalyst could be easily separated from the hydrogenated products, avoiding the necessity of filtration for industrialization.