Polychlorinated biphenyls (PCBs) can be effectively converted to bicyclohexyl in supercritical fluid carbondioxide at 100 atm and 373 K by catalytic hydrogenation reactions using palladium nanoparticles stabilizedin high-density polyethylene beads. The conversion process involves hydrodechlorination of PCBs to biphenylfollowed by its hydrogenation to cyclohexylbenzene and finally to bicyclohexyl. The catalyst can be reusedseveral dozen times without losing activity.