Solid‐Phase Upcycling Toward the Production of Ultrahigh‐Loading Single‐Atom Catalysts

The recovery of valuable transition metals from deactivated catalysts is crucial for alleviating the challenges of resource scarcity and environmental pollution. Guided by AI‐powered big data analysis, we identified an important research gap in the sustainable recovery of early transition metals and proposed a solid‐phase upcycling strategy to transform waste catalysts into highly valuable single‐atom catalysts (SACs). This involves a heat‐induced redispersion of metal aggregates into single atoms on the polycrystalline carbon nitride (PCN) support, producing highly active M1‐PCN SACs up to 20 wt% (M = Cu, Fe, Co, and Ni). Subsequent techno‐economic analysis confirms a two‐thirds reduction in production cost and greenhouse gas emissions compared to conventional hydrometallurgical and pyrometallurgical processes, thus paving a new path in the development of sustainable technologies for metal recovery.