Integrating integrated circuit wastewater into the metal catalyst supply chain.

Abstract

The rapid growth of the integrated circuit (IC) industry has led to the generation of highly complex and challenging-to-treat wastewater streams. This work presents a sustainable paradigm for transforming metal-containing IC wastewater into efficient heterogeneous catalysts. As a proof of concept, Cu-rich IC wastewater is converted into a multifunctional Cu/SiO₂ catalyst via a simple ammonia-evaporation process, achieving up to 99.9% Cu recovery. The catalyst exhibits outstanding activity in the upcycling of various real-world polyethylene terephthalate (PET) wastes to p-xylene (PX) with near-quantitative yield (>99.9%), surpassing commercial Cu/SiO₂. The superior catalytic performance is attributed to the modulation of the catalyst structure by trace coexisting metals in the wastewater, which promote the formation of abundant Cu/CuO_x interfacial sites, facilitating H₂ dissociation and C-O bond activation. Furthermore, this strategy also enables the complete transformation of Cu species onto other supports to construct various Cu-based catalysts. Overall, this work establishes a new paradigm for valorizing IC wastewater, which can be extended to other metal-containing wastewaters (e.g., Ni, Co, Pt), in alignment with the principles of green chemistry and the circular economy.