High‐Yield Synthesis of Fe‐NC Electrocatalysts Using Mg ²⁺ Templating and Schiff‐Base Porous Organic Polymers

Abstract The decoupled synthesis of Fe‐NC single‐site electrocatalysts mediated by Lewis acids enables high active site density and utilization. However, current approaches often rely on small organic molecules and suffer from low synthesis yields due to the high Lewis acid‐to‐precursor ratios required to achieve highly porous carbons. Here, a porous organic polymer (POP) based on 2,4,6‐Triaminopyrimidine (TAP) is utilized as a carbon‐nitrogen‐based scaffold for the synthesis of Fe─NC electrocatalysts. By tuning the amounts of MgCl 2 ·6H 2 O used both as porogen and active site templating agent, synthetic yields exceeding 45% are achieved, a significant improvement compared to the 6% yield from the molecular analogue and the highest reported for Mg 2+ templated systems. Subsequent low‐temperature exchange with Fe leads to atomically dispersed FeN x , minimizing Fe aggregation. The resulting materials exhibit high specific surface areas (>1000 m 2 g −1 ) with micro‐, meso‐, and macropores, which promote mass transport and active site accessibility. Compared to Fe─NC synthesized via direct pyrolysis of Fe‐coordinated POP, the decoupled method enables significantly higher catalytic activity in both alkaline and acidic media, and delivers 1 A cm −2 at 0.687 ± 0.004 V RHE in an alkaline gas diffusion electrode, highlighting its potential for practical oxygen reduction devices.