One-step fabrication of HNBR/MIL-100 composites via selective hydrogenation of acrylonitrile-butadiene rubber with a catalyst derived from MIL-100(Fe)

Heterogeneous catalyst has been widely used in hydrogenation process. However, the heterogeneous catalytic hydrogenation of acrylonitrile-butadiene rubber (NBR) usually requires high temperature and thus remains a significant challenge. Herein, an efficient MIL-100(Fe)-supported palladium (Pd) catalyst was successfully synthesized via a solution impregnation method without stabilizing and reducing agents and applied in selective hydrogenation of NBR with an in situ reduction process. Specifically, Pd²⁺ could be directly reduced to Pd⁰ during hydrogenation process, which would further get involved in the hydrogenation of NBR rapidly. As-obtained Pd(II)/MIL-100(Fe) composite exhibited highly catalytic activity toward NBR at room temperature due to the well-dispersed and small-sized Pd nanoparticles and the high external surface area of MIL-100(Fe). Furthermore, the hydrogenation degree of hydrogenated acrylonitrile-butadiene rubber (HNBR) could reach to 93% even at 10 °C. More importantly, the MIL-100/HNBR composites with improved mechanical properties could be also prepared by the one-step method through using the remained catalysts in HNBR substrate.