Emerging catalysts in electrochemical environmental remediation: advances, mechanisms, and practical challenges

The accumulation of recalcitrant anthropogenic xenobiotics necessitates advanced remediation technologies. While electrochemical advanced oxidation processes provide robust water treatment, industrial scalability remains constrained by the cost, suboptimal selectivity, and thermodynamic limits of conventional electrodes. This critical review assesses emerging electrocatalysts – including defect-engineered carbons, non-active metal oxides, single-atom catalysts (SACs), and high-entropy alloys (HEAs) – bridging atomistic chemistry with macroscopic engineering to mechanistically elucidate the transition toward highly selective non-radical degradation pathways. Diverging from traditional materials-centric summaries, this work rigorously interrogates practical industrial scale-up challenges. Specific techno-economic thresholds are established for commercial deployment: maximum specific energy demand (EEO ≤ 5.0 kWh m−³ order−¹), scalable catalyst cost caps ($50–100 USD/kg), and minimum service lifetimes (t1/2 > 4,000 h). Furthermore, the kinetic interferences of real wastewater matrices, continuous-flow reactor architectures, and the thermodynamic inevitability of active-site leaching are critically evaluated. Finally, a strategic roadmap highlights the integration of artificial intelligence (AI) for data-driven catalyst discovery, operando characterisation, and paired electrolysis to align advanced water treatment with circular economy principles.