Catalytic hydrodechlorination of dioxins over palladium nanoparticles in supercritical CO2 swollen microcellular polymers

► Pd nanoparticles are embedded in microcellular high density polyethylene (Pd/m-HDPE). ► Pd/m-HDPE is used as heterogeneous catalysts in supercritical carbon dioxide (sc-CO2). ► Dioxins are remedied via hydrodechlorination and hydrogenation over Pd/m-HDPE in sc-CO2. ► The final products are dechlorinated and benzene-ring-saturated dioxins. ► Pd/m-HDPE can be recyclable and reusable without complicated cleaning procedures.