Dual redox shuttles drive efficient succinic acid electrosynthesis from plastic and biowaste

Electrocatalytic plastic upcycling offers a promising route toward plastic waste management and circular chemical synthesis; however, uncoordinated anodic and cathodic reactions lead to non-convergent product streams, fundamentally limiting system-level efficiency and scalability. Herein, we report a dual-side electrosynthesis strategy that couples anodic plastic valorization with cathodic biowaste conversion to converge on a single target product, succinic acid (SA). In this system, 1,4-butanediol (BD) derived from polybutylene terephthalate waste is selectively oxidized to SA over NiCoAl-layered double hydroxides, achieving a selectivity of 96.5% and a Faradaic efficiency of 97.9%, with stable operation sustained for 120 h. Density functional theory calculations reveal that Co incorporation upshifts the metal d-band center and enhances metal-oxygen hybridization, thereby lowering the energy barrier for selective BD electrooxidation to SA. In parallel, biomass-derived maleic acid is electroreduced to SA over the PdPtSn catalyst, enabling synchronized SA generation at both electrochemical interfaces. Implemented in a continuous-flow electrolyzer, this dual-side electrosynthesis system achieves a SA yield of 169.1%, surpassing the single-electrode limit. Techno-economic analysis indicates that the total profit for producing per ton of SA is $1076. This work establishes product-convergent electrosynthesis as a general and scalable strategy for high-efficiency electrochemical circular manufacturing.