Catalytic deconstruction of organic additive-containing plastics

Plastics waste ends up in landfills, oceans and incinerators, posing major environmental and human health threats. Catalytic deconstruction is emerging as a key technological solution to handle complex plastics and has successfully converted virgin polymers into various products. Here we investigate the resilience of chemical deconstruction technologies to organic additives, which are ubiquitous in plastics. We study catalyst–additive interactions experimentally and via first-principles calculations for plastics additives representative of entire classes. We reveal two deactivation mechanisms and demonstrate that most recently developed catalysts are inadequate for polyolefin conversion due to poisoning caused by the strong adsorption of many additives or their small fragments. We also identify conditions and catalysts that can circumvent the challenge of deconstruction in the presence of additives. Plastic additives can hinder the mechanical recycling of plastics; a similar issue arises in chemical deconstruction, where plastic additives can deactivate catalysts. Here the authors compare hydroconversion and catalytic pyrolysis to identify specific criteria needed to mitigate the effects organic additives on the deconstruction of polyolefins.