Sequential Reduction–Oxidation Coupling Process for the Sustainable Remediation of Pollutants Containing Electron-Withdrawing Groups

Persistent and toxic organic pollutants containing strong electron-withdrawing groups (EWGs) pose a major bottleneck to ecological security and sustainable wastewater treatment. Conventional advanced oxidation processes (AOPs) struggle to degrade these pollutants because EWGs intrinsically inhibit electrophilic attack and electron transfer, whereas advanced reduction processes (ARPs) often yield highly toxic, partially reduced byproducts. While both technologies exhibit suboptimal performance when applied alone, sequential reduction-oxidation coupling (ROC) can fundamentally break through this thermodynamic bottleneck. By utilizing targeted reduction to systematically lower activation barriers, ROC enables the near-complete mineralization of recalcitrant pollutants, offering a highly promising and sustainable approach for water remediation. This review summarizes the electronic properties of EWGs and systematically evaluates recent advances in ROC technologies based on their fundamental reaction configurations. Going beyond a mere mechanistic overview, we propose a universal, descriptor-driven engineering framework to guide ROC system design. It dissects the core synergistic mechanisms, introduces predictive optimization strategies for precise reaction control, and establishes multidimensional techno-economic analysis (TEA) and life-cycle assessment (LCA) benchmarks pivotal for industrial scale-up. Ultimately, this work lays out a roadmap to guide the development of ROC technologies toward a sustainable and carbon-neutral future. Furthermore, the redox coupling paradigm elaborated herein holds promise for extending its utility beyond water treatment, providing foundational guidance for the design of next-generation sequential catalytic systems across diverse environmental and industrial applications.