Promoting CO<sub>2</sub> electroreduction on CuO nanowires with a hydrophobic Nafion overlayer

Wang, Mang; Wan, Lili; Luo, Jingshan

doi:10.1039/d0nr08369k

Cited by 31 publications

(22 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chronoamperometric curves recorded during the electrolytic experiments are shown in Figure S12, and the integrated charge densities are plotted in Figure S13. It can be observed that the bare substrate and the no catalyst-modified electrode show similar small charge densities at −0.75 and −0.8 V due to the slow reaction rates, while at a more negative applied potential, the charge density of the no catalyst-modified electrode increases significantly compared to that of the bare substrate, which may be attributed to the higher local concentration of AN caused by the hydrophobic Nafion coating . In the presence of the MOF-derived electrocatalysts in the thin films, the charge densities at −0.75 and −0.8 V can be remarkably increased, which indicates that the MOF-derived electrocatalysts can initiate the electrochemical reactions at a lower overpotential compared to the bare Pb electrode and the Nafion-modified electrode.…”

Section: Resultsmentioning

confidence: 95%

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Wang

Yen

Huang

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Electrochemical conversion of acrylonitrile (AN) to produce adiponitrile (ADN), the raw material for the production of Nylon 66, has become a crucial process owing to the increasing market demand of Nylon 66. Although the metallic Pb or Cd electrodes are commonly used for this reaction, the use of electrocatalysts or electrodes modified with catalysts has been barely investigated. In this study, nanoporous and electrically conductive metal–organic framework (MOF)-derived materials composed of Pb, PbO, and carbon are synthesized by carbonizing a Pb-based MOF through thermal treatments, and these MOF-derived materials are served as electrocatalysts for the electrosynthesis of ADN. The crystallinity, morphology, elemental composition, porosity, electrical conductivity, and electrochemically active surface area of each MOF-derived material are investigated. Mass-transport-corrected Tafel analysis is used to probe the enhanced kinetics for the electrochemical reduction of AN occurring at the electrode modified with the MOF-derived material. Electrolytic experiments at various applied potentials are conducted to quantify the production rate and Faradaic efficiency toward ADN, and the result shows that the MOF-derived materials can act as electrocatalysts to initiate the electrochemical reduction of AN to produce ADN at a reduced overpotential. The optimal MOF-derived electrocatalyst can achieve a Faradaic efficiency of 67% toward ADN at an applied potential of −0.85 V versus reversible hydrogen electrodea much lower overpotential compared to that typically required for this reaction without the use of catalysts. Findings here shed light on the design and development of advanced electrocatalysts to boost the performances for the electrosynthesis of ADN.

show abstract

Section: Resultsmentioning

confidence: 95%

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Wang

Yen

Huang

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…Previous studies point to the hydrophobic alkyl groups of CTAB in the catalyst microenvironment increasing the ratio of CO 2 -to-water near the catalyst surface. 36,37 To confirm this to be the case in our reactor, we ran similar experiments with dodecyltrimethylammonium bromide (DTAB), a quaternary ammonium surfactant with a 12-carbon alkyl chain (the alkyl chains of CTAB contain 16 carbon atoms; Figure S10). The DTAB-doped solution yielded a lower i CO2RR (89 ± 5 mA cm −2 ) than the CTAB-doped solution (162 ± 10 mA cm −2 ), yet both surfactants yielded a similar distribution of CO2RR products (Figure S10).…”

mentioning

confidence: 75%

Electrolytic Methane Production from Reactive Carbon Solutions

et al. 2022

View full text Add to dashboard Cite

We report an electrochemical reactor that converts 3.0 M KHCO3 into methane at the cathode, and oxidizes water at the anode. The molar ratio of methane product to unreacted CO2 gas (defined herein as “methane yield”) was measured to be 34% at a partial current density of 120 mA cm–2. The highest previously reported CO2-to-methane yield is 3%. Our reactor achieved this improvement in methane yield because it is fed with 3.0 M KHCO3, a type of reactive carbon solution, rather than gaseous CO2. The reactor uses H+ delivered by a bipolar membrane to form CO2 at the cathode. This CO2 is subsequently reduced into methane. A cationic surfactant added to the catholyte suppressed hydrogen evolution and increased methane formation. A 1D continuum model confirmed that H+ from the membrane promotes the formation of methane over multicarbon products at the cathode. These findings present design principles for electrochemical methane synthesis.

show abstract

“…We also compared the performance of the Cu-FEP sample with the reported state-of-the-art Cu-based catalysts in H-cells [8,21,[33][34][35][36]22,[26][27][28][29][30][31][32] and flow cells [18,24,[37][38][39][40][41] (Figure 5d), in terms of the partial current density and the applied potential. It is clear that in both the H-cell and flow cell reactors, our Cu-FEP sample is among the best Cu-based catalysts documented in the literature, showcasing high C 2+ selectivity and current density at relatively low overpotentials.…”

Section: Co 2 Rr Performancementioning

confidence: 99%

Enhanced Electrocatalytic CO₂ Reduction to C₂₊ Products by Adjusting the Local Reaction Environment with Polymer Binders

Pham

Zhang

et al. 2022

Advanced Energy Materials

124

View full text Add to dashboard Cite

sequestrated. Recently, electrochemical CO 2 reduction reactions (CO 2 RR) enabled by renewable energy have been suggested as a promising strategy to solve these problems, sequestrating discharged CO 2 into chemical feedstocks, and downscaling the use of fossil fuels in the chemical production industry. In addition, CO 2 RR is an efficient way to store electricity generated from intermittent renewable energies in the form of liquid fuels for transport and other applications. [3][4][5] Copper-based materials are the most investigated class of catalysts for CO 2 RR due to their unique ability to reduce CO 2 molecules to carbonaceous compounds containing more than two carbon atoms (C 2+ products). However, the high overpotential required and the low product selectivity over the pristine Cu surface have motivated researchers to develop more efficient strategies to overcome these challenges. Most previous publications have focused on engineering the properties of Cu-based catalysts, such as optimizing the size and shape of Cu nanomaterials, [6][7][8][9][10] introducing grain boundaries, [11] and creating alloys with other metals [12][13][14][15] to increase the number of active sites and/or to improve the intrinsic catalytic activities of Cu toward the desired products. Despite the tremendous progress that has been made, CO 2 RR is still not viable at an industrial scale.The activity and selectivity of the electrochemical CO 2 reduction reaction (CO 2 RR) are often hindered by the limited access of CO 2 to the catalyst surface and overtaken by the competing hydrogen evolution reaction. Herein, it is revealed that polymers used as catalyst binders can effectively modulate the accessibility of CO 2 relative to H 2 O at the vicinity of the catalyst and thus the performance of CO 2 RR. Three polymers with different hydrophilicities (i.e., polyacrylic acid (PAA), Nafion, and fluorinated ethylene propylene (FEP)) are selected as binders for Cu catalysts. At a thickness of only ≈1.2 nm, these binders strongly affect the activity and selectivity toward multi-carbon (C 2+ ) products. The FEP coated catalyst exhibits a C 2+ partial current density of over 600 mA cm −2 with ≈77% faradaic efficiency at −0.76 V versus RHE. This high performance is attributed to the hydrophobic (aerophilic) properties of FEP, which reduces the local concentration of H 2 O and enhances that of the reactant (i.e., CO 2 ) and the reaction intermediates (i.e., CO). These findings suggest that tuning the hydrophobicity of electrocatalysts with polymer binders can be a promising way to regulate the performance of electrochemical reactions involving gas-solid-liquid interfaces.

show abstract

Promoting CO₂ electroreduction on CuO nanowires with a hydrophobic Nafion overlayer

Abstract: A hydrophobic electrode surface was constructed by modifying the CuO nanowire electrode with a thick Nafion overlayer, which exhibited enhanced selectivity toward the CO2 electroreduction reaction and suppressed hydrogen evolution activity.

Cited by 31 publications

References 37 publications

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Electrolytic Methane Production from Reactive Carbon Solutions

Enhanced Electrocatalytic CO₂ Reduction to C₂₊ Products by Adjusting the Local Reaction Environment with Polymer Binders

Contact Info

Product

Resources

About

Promoting CO2 electroreduction on CuO nanowires with a hydrophobic Nafion overlayer

Abstract: A hydrophobic electrode surface was constructed by modifying the CuO nanowire electrode with a thick Nafion overlayer, which exhibited enhanced selectivity toward the CO2 electroreduction reaction and suppressed hydrogen evolution activity.

Cited by 31 publications

References 37 publications

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Electrolytic Methane Production from Reactive Carbon Solutions

Enhanced Electrocatalytic CO2 Reduction to C2+ Products by Adjusting the Local Reaction Environment with Polymer Binders

Contact Info

Product

Resources

About

Promoting CO₂ electroreduction on CuO nanowires with a hydrophobic Nafion overlayer

Enhanced Electrocatalytic CO₂ Reduction to C₂₊ Products by Adjusting the Local Reaction Environment with Polymer Binders