Hierarchical porous organometallic polymers enable industrial-level acidic CO2 electroreduction†

Heterogenized molecular electrocatalysts hold great promise for the electrocatalytic conversion of CO₂ into higher-value products. However, their practical application is hindered by the aggregation due to π–π interactions and the instability from cobalt site leaching. Using cobalt phthalocyanine (CoPc) as a model system, we present a simple hyper-crosslinking strategy to fabricate a three-dimensional porous organometallic polymer (CoPc POP) with enhanced activity and stability. This approach preserves the excellent catalytic performance of CoPc while ensuring uniform dispersion of active sites within the porous channels. The maximized exposure of Co sites improves electron and substrate interactions, leading to significantly enhanced CO₂ reduction reaction (CO₂RR) performance. Even in an electrolyte with a pH of 1, the optimized CoPc POP catalyst achieves an impressive CO Faradaic Efficiency (FE_CO) of 91.2% at a high current density of 850 mA cm⁻², with a turnover frequency (TOF) of 3.10 × 10⁴ h⁻¹. Notably, the robust polymer framework effectively mitigates cobalt site leaching, maintaining an FE_CO above 95.7% during a 14 hour stability test.