Catalytic debromination of waste brominated resin by co-pyrolysis with Pd-containing spent automotive catalysts

A "treating the wastes with wastes" approach was provided in this study, where spent automotive catalysts were added into waste brominated resin for debromination by co-pyrolysis. Spent automotive catalyst in this study was the Pd-only ternary automotive catalyst and the content of Pd was 493.89 μmol/kg. The proportions of Pd(0) and Pd(Ⅱ) in spent automotive catalyst were 86.37% and 13.63%, respectively. Wrapped Pd invalidated the catalytic effect of automotive catalyst. The debromination rate of brominated resin could be increased from 12.73% to 66.86% after co-pyrolysis with spent automotive catalyst powder at 260°C. The catalytic debromination of Pd on brominated resin relied on the oxidative addition and decomposition reactions. Aryl bromides in 2,2′,4,4′-tetrabromodiphenyl ether would be attacked by Pd in turn according to the higher positive charge. This work contributes scientific information and approach to the reuse of spent automotive catalysts and the safe disposal of brominated resin together.