Catalytic bromine recycling from waste

Abstract

Bromine (Br), mostly extracted from nature, plays an essential role in the form of organobromides in various goods, including electronics, vehicles and furniture. At the same time, Br is continuously released into the environment in the form of persistent brominated pollutants upon the retirement of those goods, causing severe environmental consequences and loss of resources. Here we propose a catalytic strategy that enables the selective and mild-condition conversion of all organobromides present in wastes into renewed bromides for Br recycling. It employs Ullmann-type reactions enabled by inexpensive Cu(I), simple ligands and hydroxides in DMSO–H2O solvent. This strategy achieved >95% bromide yields at a temperature ≤120 °C for complex real-world Br-laden wastes. It can produce bromide-rich solution amenable to Br2 production, as demonstrated by the inorganicization–evaporation–oxidation process, and recoverable debrominated solids with preserved chemical states. Mechanistic studies revealed a full debromination framework encompassing diverse activated pathways. This work provides a viable approach for Br recycling and potentially facilitates a circular and sustainable anthropogenic Br flow. Bromine (Br) has indispensable roles in manufacturing many products but mostly ends up in waste, leading to both resource loss and environmental pollution. Here the authors proposes a catalytic process to enable Br recycling from real-world Br-laden wastes.