Porphyrin-based covalent organic frameworks for electrocatalytic NO_x reduction and C-N coupling reactions

Porphyrin-based covalent organic frameworks (COFs) have emerged as versatile and structurally tailorable platforms for the electrocatalytic conversion of nitrogen oxides (NO_x) to value-added chemicals. Their structural periodicity, well-defined coordination environments, and tunable electronic properties render them particularly attractive for both NO_x electroreduction (NO_xRR) and NO_xRR-coupled C-N bond-forming reactions. This review summarizes recent advances in porphyrin-based COFs for NO_x electroreduction, highlighting their structure-activity relationships and catalytic mechanisms. Special emphasis is placed on their role in promoting C-N coupling reactions toward high-value organonitrogen products, such as urea, under mild electrochemical conditions. Finally, current challenges, including activity, selectivity, and mechanistic understanding, are discussed, together with perspectives on the rational design of next-generation porphyrin-based COF electrocatalysts.