Materials that recover dilute metals and convert the recovered species into functional catalysts can link resource circularity with environmental remediation, yet their design is constrained by a trade-off between rapid transport and reactive binding. Here, we report a ZIF−8-derived hollow N-doped porous carbon (HNPC) as a capture-to-catalyst platform for closed-loop gold recovery and nitrate-to-ammonia electrocatalysis. The hollow mesoporous framework shortens diffusion pathways and improves access to internal surfaces, whereas graphitic-N-associated sites promote AuCl₄⁻ adsorption and Au(III)-to-Au(0) reduction. The optimized HNPC exhibits a Langmuir Au(III) capacity of 3245.1 mg·g^-1 and removes >99.9% of Au at trace concentrations under strong ionic competition, corresponding to a distribution coefficient of ~3×10⁹ mL·g⁻¹. Time‑resolved microscopy and spectroscopy reveal rapid Au nanoparticle nucleation and progressive conversion to Au(0), while finite−element simulations and density functional theory (DFT) identify the cooperative roles of hollow-structure-enabled transport and graphitic-N-regulated interfacial reactivity. The resulting Au/HNPC is directly reused as a gas-diffusion-electrode catalyst, delivering 96.6% Faradaic efficiency for nitrate-to-ammonia conversion and stable operation for 535 h at 200 mA·cm⁻²_. This work establishes a materials strategy for integrating selective recovery, in situ metal formation, and catalytic reuse in complex aqueous media.

The overuse and ineffective management of plastics have led to significant environmental pollution. Catalytic upcycling into value-added chemicals has emerged as a promising solution. This review provides a comprehensive overview of recent advances in catalytic upcycling, focusing on the cleavage of chemical bonds such as carbon–carbon (C–C), carbon–oxygen (C–O), and carbon–hydrogen (C–H) in plastics. It systematically discusses plastics conversion via electrocatalysis, thermal catalysis, and photocatalysis. Additionally, it explores the conversion of plastics into value-added chemicals and functional polymers. The review also addresses the challenges in this field and aims to offer insights for developing sustainable and effective plastics upcycling technologies.