Enhanced CO2 electroreduction to formate over tin coordination polymers via amino-functionalization

Electroreduction of CO2 into value-added products relies on the availability of highly active/selective and robust catalysts. Herein, we report a strategy to controllably enhance the catalytic activity of tin coordination polymers (Sn-CPs) for CO2 electroreduction via framework functionalization. By adjusting ligands, amino groups (-NH2) were successfully introduced into the framework of Sn-CPs, enabling the enhanced CO2 adsorption capacity and effectively suppressed H2 evolution (H2 Faraday efficiency (FE) < 10%) with lower overpotentials. With the highest surface Sn2+ content and most –NH2 functional groups in the framework among three Sn-CPs, Sn-DaPTA (tin 2,5-diaminoterephthalate) delivered the highest formate FE of 85% with a current density of 11 mA/cm2 at −0.8 V (vs. RHE) and maintained stable performance during 18 reuse cycles. This work opens a new avenue for promoting the CO2 electroreduction performance of CPs via amino-functionalization.