Silver still faces significant challenges in the electrochemical reduction of CO_(2)(eCO_(2)RR)to CO under elevated current density with high energy input due to the intensified hydrogen evolution reaction.The doping ...Silver still faces significant challenges in the electrochemical reduction of CO_(2)(eCO_(2)RR)to CO under elevated current density with high energy input due to the intensified hydrogen evolution reaction.The doping of 2 mol%Re-oxide into Ag aerogel results in a significant decrease in the onset potential and a twofold increase in the current density compared to a pure Ag aerogel(Ag100),which tackles the issue.The effect is rationalized in terms of positively shifting the d-band center close to the Fermi energy level to change the density of local electronic states.Moreover,upon the adsorption of the ionic liquid(IL,1-Allyl-3-methylimidazolium dicyanamide[AMIM][DCN])onto the surface of Re-oxide doped Ag aerogel(Ag_(98)Re_(2)/IL),the current density increases to 320 mA/cm^(2) at a low of-1.3 V vs.RHE with 96%selectivity for CO formation in an alkaline medium using a flow cell electrolyzer,and maintains the selectivity above92%for up to 17 h using an H-cell electrolyzer.Density Functional Theory revealed that the adsorbed IL forms a highly conductive and hydrophobic layer on the aerogel surface,presumably decreasing the local H+concentration,greatly suppressing the hydrogen evolution reaction while enhancing the eCO_(2)RR pathway and mitigating the mass transport issues typically associated with IL use.This work addressed the key challenges in massively producing CO from eCO_(2)RR,offering a promising strategy for scalable and industrial CO generation.展开更多
基金Funding from the Natural Science and Engineering Research Council of Canada(RGPIN-2022-03129)China Scholarship Council(202308210183)the University of Toronto is gratefully acknowledged。
文摘Silver still faces significant challenges in the electrochemical reduction of CO_(2)(eCO_(2)RR)to CO under elevated current density with high energy input due to the intensified hydrogen evolution reaction.The doping of 2 mol%Re-oxide into Ag aerogel results in a significant decrease in the onset potential and a twofold increase in the current density compared to a pure Ag aerogel(Ag100),which tackles the issue.The effect is rationalized in terms of positively shifting the d-band center close to the Fermi energy level to change the density of local electronic states.Moreover,upon the adsorption of the ionic liquid(IL,1-Allyl-3-methylimidazolium dicyanamide[AMIM][DCN])onto the surface of Re-oxide doped Ag aerogel(Ag_(98)Re_(2)/IL),the current density increases to 320 mA/cm^(2) at a low of-1.3 V vs.RHE with 96%selectivity for CO formation in an alkaline medium using a flow cell electrolyzer,and maintains the selectivity above92%for up to 17 h using an H-cell electrolyzer.Density Functional Theory revealed that the adsorbed IL forms a highly conductive and hydrophobic layer on the aerogel surface,presumably decreasing the local H+concentration,greatly suppressing the hydrogen evolution reaction while enhancing the eCO_(2)RR pathway and mitigating the mass transport issues typically associated with IL use.This work addressed the key challenges in massively producing CO from eCO_(2)RR,offering a promising strategy for scalable and industrial CO generation.
