CO2-affinitive Surface of Metal/Nafion Attributable to Selective Polarization for Superior CO2RR

CO2 reduction reaction (CO2RR) has been considered as a promising process that can compensate CO2 emission and convert it into value-added chemicals. In preparation of CO2RR catalytic electrode, Nafion is a common binder but its effect in catalytic process is usually ignored. Herein, we proposed the bifunction of Nafion in CO2RR based on its molecular structure and successfully developed a CO2-affinitive surface of Micro-Ag /Nafion by controlling the content of Nafion, which exhibited a superior CO faradaic efficiency (FECO) of 95.07% at -0.9 V (vs. RHE). This excellent FECO and 2 times of CO partial current density (jCO) in flow-cell proved its industrial prospect. Its splendid selectivity of CO2RR was attributed to the selective polarization of CO2 molecule at Nafion, which resulted in the 6.8 times higher adsorption energy (Eads) of CO2 than H2O. Therefore, CO2RR gained an advantage in the competitive reaction.Nafion was recognized as a favorable transporter for CO2 on the surface of metal catalyst. Our work describes the bifunctional role of Nafion in CO2RR electrode and it will contribute to optimize the design of metal/Nafion catalytic material for CO2RR.