TY  - JOUR
AU  - Xu, Heng-Yue
AU  - Yu, Zhi-Wu
PY  - 2026
TI  - Mechanistic insights into PET and PU degradation on bio-inspired dual-metal catalysts
JO  - Nano Research
SN  - 1998-0124
SP  - 94908386
VL  - 19
IS  - 4
AB  - Understanding how polymer backbone chemistry governs catalytic hydrolysis remains essential for designing efficient plastic-degrading catalysts. Here, we combine molecular dynamics (MD) and density functional theory (DFT) analyses to construct a unified mechanistic picture of polyethylene terephthalate (PET) and polyurethane (PU) degradation on bio-inspired dual-metal catalysts. Tetramers are taken for MD simulations, and model molecules containing key fragments of the two polymers are used for DFT investigations. MD simulations reveal that PET adopts flexible, weakly hydrated conformations, while PU forms compact hydrogen-bond networks stabilized by intramolecular N–H···O=C interactions. Guided by enzymatic motifs, a family of dual-atom catalysts hosted on nitrogen-doped carbon supports (M2N6@C, M = Fe, Co, Ni, Cu, Zn) was designed to emulate cooperative active sites found in metalloenzymes. DFT results show that both reactions proceed through a five-state cycle—adsorption, nucleophilic attack, tetrahedral intermediate, bond cleavage, and product desorption—but exhibit distinct rate-determining steps. Cu2N6@C achieves the lowest barrier for PET (0.226 eV, desorption-controlled), while Fe2N6@C most effectively activates PU (0.416 eV, polarization-controlled). Electronic-structure analyses show that shorter Fe–Fe pairs excel at activating compact, strongly bound urethane groups of PU through polarization, whereas longer Cu–Cu pairs optimally engage extended ester bonds of PET through adaptive coordination and charge delocalization. These findings establish direct correlations between metal–metal distance, spin state, and substrate selectivity, providing molecular design principles that bridge enzymatic cooperativity with heterogeneous dual-metal catalysis for selective plastic depolymerization.
UR  - https://doi.org/10.26599/NR.2026.94908386
DO  - 10.26599/NR.2026.94908386