Reversible copper coordination redirects pyrolysis products in waste polyurethane enamelled copper wire

Abstract Here we address a key mechanistic question that limits thermochemical upcycling of waste polyurethane wire: copper is not an inert background but actively redirects pyrolysis products. We propose a copper-assisted dynamic pyrolysis model in which copper reshapes the conversion-dependent energy-barrier profile through electronic-structure regulation, leading to a predictable shift in dominant reaction routes. Thermogravimetric analysis reveals a robust three-stage decomposition and a pronounced evolution of apparent barriers with conversion, consistent with a late-stage regime governed by radical reorganisation, condensation and char formation. Temperature-resolved product fingerprints provide direct chemical evidence for pathway selectivity. Reversible copper coordination and frontier-orbital interactions lower key transition barriers and stabilise intermediates, promoting radical recombination and aromatization. These results establish a cross-scale link between macroscopic pyrolysis behavior, barrier evolution and product selectivity, and offer a general framework for endogenous metal regulation, supporting cleaner processing and improved copper recovery.