MOF-Derived Electrocatalysts for the Remediation of Persistent Nitroaromatic Pollutants: Structure-Guided Design, Mechanistic Insights, and Performance Evaluation

Persistent nitroaromatic pollutants are difficult to remediate because their molecular structures resist biodegradation and conventional treatment, and incomplete transformation can generate persistent or toxic intermediates. Metal–organic framework (MOF)-derived electrocatalysts are promising candidates for their removal owing to their tunable metal coordination environments, hierarchical porosity, and adaptable catalytic interfaces. This review critically examines how precursor chemistry, catalyst structure, and electrocatalytic performance are related, with emphasis on the roles of metal speciation, heteroatom coordination, pore architecture, and interfacial properties in regulating adsorption, electron transfer, and reaction selectivity. The mechanisms of cathodic nitro-group reduction and anodic oxidation are discussed, with particular attention to competing hydrogen evolution, active-site reconstruction, catalyst deactivation, and hazardous transformation products. Pollutant-specific challenges are examined for nitro-containing pharmaceuticals, nitro-polycyclic aromatic hydrocarbons, chloronitrobenzenes, nitroanilines, nitrophenols, and nitroaromatic explosives. Beyond parent-compound removal, the review emphasizes transformation-product identification, toxicity assessment, carbon and nitrogen balances, metal leaching, energy consumption, and life-cycle impacts as essential evaluation criteria. Quantitative descriptors (Faradaic efficiency, turnover frequency, active-site density, and energy consumption), criteria for distinguishing genuine electronic synergy from physical effects, binder effects, and minimum reporting requirements are consolidated into actionable recommendations for experimental design. Finally, pollutant-backward catalyst design, dynamic paired electrolysis, toxicity-aware process control, and artificial intelligence-assisted discovery are highlighted as emerging directions. Integrating mechanistic understanding, reliable performance data, and environmental risk assessment will be critical for developing selective, sustainable, and deployable MOF-derived electrocatalysts.