Polyacrylamide-Mediated Silver Nanoparticles for Selectively Enhancing Electroreduction of CO₂ towards CO in Water

Conversion of the greenhouse gas CO₂ to value-added products is an important challenge for sustainable energy research. Here, a durably nanohybrid composed of Ag nanoparticles and polyacrylamide was constructed for the selectively electroreduction of CO₂ to CO. The nanohybrid exhibited an outstanding CO faradaic efficiency of 97.2±0.2 % at -0.89 V_RHE (vs. the reversible hydrogen electrode) with a desirable CO partial current density of -22.0±2.3 mA cm^-2 and maintained the CO faradaic efficiency above 95 % over a wide potential range (-0.79 to -1.09 V_RHE ), showing excellent stability during a 48 h prolonged electrolysis. The origins of selective enhancement of CO₂ reduction over the nanohybrid stemmed from the activation of CO₂ via hydrogen bond and the low basicity of the amide. DFT calculations implied that the synergy of Ag nanoparticles and amide could better stabilize the key intermediate (*COOH) and effectively lower the overpotential of CO₂ reduction. These results establish the synergistic effects of organic/inorganic hybrid as a complementary method for tuning selectivity in CO₂ -to-fuels catalysis.