From lab-scale performance to field barriers: electrocatalytic nitrate treatment for sustainable water remediation

Abstract

Electrocatalytic nitrate reduction (eNO₃RR) offers a promising route for sustainable water remediation coupled with resource recovery, yet the translation from lab-scale catalyst innovation to field-scale implementation faces significant barriers. This comprehensive review critically bridges this gap, moving beyond conventional mechanistic discussions to adopt a conversion-centric perspective. We systematically analyze advances in eNO₃RR catalysts—including transition metals, alloys, and carbon-based materials—and directly link these innovations to critical field-scale challenges: ionic interference, energy economics, reactor scalability, and product selectivity. Crucially, we reframe nitrate pollution as an opportunity, expanding the scope beyond ammonia synthesis to encompass high-value chemical production, energy storage, and carbon–nitrogen synergistic conversion, thereby positioning wastewater as a circular resource hub. To overcome existing barriers, we propose a multi-solution framework integrating AI-guided catalyst design, hybrid systems (e.g., photovoltaic–electrocatalytic coupling), and circular business models. This framework aims to advance eNO₃RR towards a sustainable “pollution control–resource regeneration” paradigm. We advocate for holistic evaluation using techno-economic analysis (TEA) and carbon footprint assessment to provide a scalability-first roadmap for global deployment. This review catalyzes a paradigm shift from pollution mitigation to value creation, offering critical guidance for sustainability-driven industrial transitions.