Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Here...Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.展开更多
Nafion/TiO2 composite membranes were prepared by in-situ chemical reaction method using Ti(OC4H9)4 and Nafion 117 as raw materials. The membranes were characterized by UV, FTIR-ATR and XRD, respectively. Methanol perm...Nafion/TiO2 composite membranes were prepared by in-situ chemical reaction method using Ti(OC4H9)4 and Nafion 117 as raw materials. The membranes were characterized by UV, FTIR-ATR and XRD, respectively. Methanol permeability and water uptake were investigated as a function of TiO2 contents. The conductivity of the membranes was measured under water vapor pressure (2.644 7 kPa) or in dry atmospheres. The XRD results showed that the titanium dioxide in Nafion membranes were crystallized in anatase phase with an average crys- taline diameter of 3.0 nm. The water uptake of the composite membranes was larger than that of the pure Nafion○ membrane when the TiO2 loading was within 14wt%. The methanol permeability of the membrane decreased as the TiO2 loading increased. The addition of 3wt% TiO2 to Nafion○ membranes improved the conductivity in dry measurement conditions. The proton conductivity of the composite membrane increased greatly after the hy- drothermal treatment at 160 ℃ for 2 hours.展开更多
基金financially supported by the Natural Science Foundation of Guangdong Province (2022A1515012359)the National Natural Science Foundation of China (21902121)+1 种基金the STU Scientific Research Foundation for Talents (NTF21020)the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (2020LKSFG09A)。
文摘Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.
文摘Nafion/TiO2 composite membranes were prepared by in-situ chemical reaction method using Ti(OC4H9)4 and Nafion 117 as raw materials. The membranes were characterized by UV, FTIR-ATR and XRD, respectively. Methanol permeability and water uptake were investigated as a function of TiO2 contents. The conductivity of the membranes was measured under water vapor pressure (2.644 7 kPa) or in dry atmospheres. The XRD results showed that the titanium dioxide in Nafion membranes were crystallized in anatase phase with an average crys- taline diameter of 3.0 nm. The water uptake of the composite membranes was larger than that of the pure Nafion○ membrane when the TiO2 loading was within 14wt%. The methanol permeability of the membrane decreased as the TiO2 loading increased. The addition of 3wt% TiO2 to Nafion○ membranes improved the conductivity in dry measurement conditions. The proton conductivity of the composite membrane increased greatly after the hy- drothermal treatment at 160 ℃ for 2 hours.
