1
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Ligthart N, van Langevelde PH, Padding JT, Hetterscheid DG, Vermaas DA. 20-Fold Increased Limiting Currents in Oxygen Reduction with Cu-tmpa by Replacing Flow-By with Flow-Through Electrodes. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2024; 12:12909-12918. [PMID: 39211382 PMCID: PMC11351704 DOI: 10.1021/acssuschemeng.4c03919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 09/04/2024]
Abstract
Electrochemical oxygen reduction is a promising and sustainable alternative to the current industrial production method for hydrogen peroxide (H2O2), which is a green oxidant in many (emerging) applications in the chemical industry, water treatment, and fuel cells. Low solubility of O2 in water causes severe mass transfer limitations and loss of H2O2 selectivity at industrially relevant current densities, complicating the development of practical-scale electrochemical H2O2 synthesis systems. We tested a flow-by and flow-through configuration and suspension electrodes in an electrochemical flow cell to investigate the influence of electrode configuration and flow conditions on mass transfer and H2O2 production. We monitored the H2O2 production using Cu-tmpa (tmpa = tris(2-pyridylmethyl)amine) as a homogeneous copper-based catalyst in a pH-neutral phosphate buffer during 1 h of catalysis and estimated the limiting current density from CV scans. We achieve the highest H2O2 production and a 15-20 times higher geometrical limiting current density in the flow-through configuration compared to the flow-by configuration due to the increased surface area and foam structure that improved mass transfer. The activated carbon (AC) material in suspension electrodes, which have an even larger surface area, decomposes all produced H2O2 and proves unsuitable for H2O2 synthesis. Although the mass transfer limitations seem to be alleviated on the microscale in the flow-through system, the high O2 consumption and H2O2 production cause challenges in maintaining the initially reached current density and Faradaic efficiency (FE). The decreasing ratio between the concentrations of the O2 and H2O2 in the bulk electrolyte will likely pose a challenge when proceeding to larger systems with longer electrodes. Tuning the reactor design and operating conditions will be essential in maximizing the FE and current density.
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Affiliation(s)
- Nathalie
E.G. Ligthart
- Department
of Chemical Engineering, Delft University
of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Phebe H. van Langevelde
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Johan T. Padding
- Department
of Process and Energy, Delft University
of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands
| | - Dennis G.H. Hetterscheid
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - David A. Vermaas
- Department
of Chemical Engineering, Delft University
of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
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2
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Xu A, Yang Z, Zhou Z, Yang P, Yu Y, Liu J, Zhang Y. Trans-electrode pressure of gas-diffusion electrodes significantly influencing the electrochemical hydrogen peroxide production. CHEMOSPHERE 2024; 361:142464. [PMID: 38810795 DOI: 10.1016/j.chemosphere.2024.142464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/17/2024] [Accepted: 05/25/2024] [Indexed: 05/31/2024]
Abstract
Hydrogen peroxide (H2O2) synthesis by electrochemical two-electron oxygen reduction has garnered increasing interest as a wide range of potential applications. Gas diffusion electrodes (GDEs) can effectively promote the H2O2 production efficiency by overcoming the oxygen mass transfer limitations but strongly influenced by the electrowetting process along the long-term operation. In this study, the effect of trans-electrode pressure (TEP) of GDE cathode on the electrowetting process was further elucidated. We controlled the TEP values of four types of GDEs: two Ni-based GDEs and two carbon cloth GDEs prepared by hot-pressing or brushing carbon black. SBA-15 was further used to regulate the microstructure of one Ni-based GDE. It was found that an optimal range of TEP occurred for all tested GDEs in terms of the max. concentration, the yield efficiency, the energy consumption, and the stability because TEP may change the triple-phase interface and influence the anti-electrowetting effect. The porosity of hot-pressed Ni GDE can maintain the TEP window and thus enhance the production of H2O2, likely via creating oxygen-containing functional groups and a bimodal pore structure on the electrode, revealed with several characterization techniques including SEM, CA, XPS, Raman spectra, CV and EIS. The porous Ni GDE presented an efficient and stable production of H2O2 for 10 cycles: yielding H2O2 at 4393.2-4602.2 mmol m-2 h-1 with current efficiencies of 94.2-98.7%. The best accumulated H2O2 concentration can reach up to 3.58 ωt% H2O2 at 10 h. The results provide an important reference for the industrial scaleup of electro-production of H2O2 with GDEs.
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Affiliation(s)
- Anlin Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Ziyan Yang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zhiyi Zhou
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Pu Yang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Yang Yu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Jiayang Liu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China.
| | - Yunhai Zhang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China.
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3
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Wiesner F, Woodford J, Sabharwal M, Hesselmann M, Jung S, Wessling M, Secanell M. Unveiling the Role of PTFE Surface Coverage on Controlling Gas Diffusion Layer Water Content. ACS APPLIED MATERIALS & INTERFACES 2024; 16:34947-34961. [PMID: 38938019 DOI: 10.1021/acsami.4c04641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Gas diffusion layers (GDLs) are usually coated with a hydrophobic agent to achieve a delicate balance between liquid and gas phases to maximize mass transport. Yet, most GDL numerical models to date have assumed an average contact angle for all materials, thereby eliminating the possibility of studying the role of the polytetrafluoroethylene (PTFE) content. This study introduces two mixed wettability algorithms to predict the mixed wetting behavior of GDLs composed of multiple materials. The algorithms employ contact angle and distance to solid materials to determine the critical capillary pressure for each pore voxel. The application of the algorithms to the estimation of capillary pressure vs saturation curves for two GDLs, namely, a micro-computed tomography (μ-CT) reconstructed SGL 39BA GDL and a stochastically reconstructed Toray 120C GDL, showed that, in agreement with experimental data, the addition of PTFE resulted in a decrease in saturation at a given capillary pressure. For Toray-120C, the mixed wettability model was capable of reproducing experimentally observed features in the intrusion curve at low saturation that could not be reproduced with a single wettability model, providing a clear link between PTFE coverage and intrusion at low saturation. Numerical results also predicted an increased breakthrough pressure and a decrease in saturation with increasing PTFE, in agreement with experimental observations. The decreased saturation at breakthrough improves gas transport through the layer while maintaining the layer's ability to remove water. Diffusivity simulations confirm the increase in diffusivity at breakthrough with increasing PTFE, thereby providing a rationale for the addition of PTFE, as well as for the optimal amount. This study emphasizes the importance of multimaterial wetting models and calls for more detailed investigations into PTFE and ionomer distributions in GDLs and catalyst layers, respectively.
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Affiliation(s)
- Florian Wiesner
- Chemical Process Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen 52074, Germany
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - James Woodford
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Mayank Sabharwal
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Matthias Hesselmann
- Chemical Process Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen 52074, Germany
| | - Seongyeop Jung
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Matthias Wessling
- Chemical Process Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen 52074, Germany
- DWI─Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, Aachen 52074, Germany
| | - Marc Secanell
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
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4
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Brosch S, Wiesner F, Decker A, Linkhorst J, Wessling M. Spatio-Temporal Electrowetting and Reaction Monitoring in Microfluidic Gas Diffusion Electrode Elucidates Mass Transport Limitations. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2310427. [PMID: 38386289 DOI: 10.1002/smll.202310427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/15/2024] [Indexed: 02/23/2024]
Abstract
The use of gas diffusion electrodes (GDEs) enables efficient electrochemical CO2 reduction and may be a viable technology in CO2 utilization after carbon capture. Understanding the spatio-temporal phenomena at the triple-phase boundary formed inside GDEs remains a challenge; yet it is critical to design and optimize industrial electrodes for gas-fed electrolyzers. Thus far, transport and reaction phenomena are not yet fully understood at the microscale, among other factors, due to a lack of experimental analysis methods for porous electrodes under operating conditions. In this work, a realistic microfluidic GDE surrogate is presented. Combined with fluorescence lifetime imaging microscopy (FLIM), the methodology allows monitoring of wetting and local pH, representing the dynamic (in)stability of the triple phase boundary in operando. Upon charging the electrode, immediate wetting leads to an initial flooding of the catalyst layer, followed by spatially oscillating pH changes. The micromodel presented gives an experimental insight into transport phenomena within porous electrodes, which is so far difficult to achieve. The methodology and proof of the spatio-temporal pH and wetting oscillations open new opportunities to further comprehend the relationship between gas diffusion electrode properties and electrical currents originating at a given surface potential.
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Affiliation(s)
- Sebastian Brosch
- RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
| | - Florian Wiesner
- RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
| | - Alexandra Decker
- RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
| | - John Linkhorst
- RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
- Verfahrenstechnik elektrochemischer Systeme, Technical University Darmstadt, Otto-Berndt-Str. 2, 64287, Darmstadt, Germany
| | - Matthias Wessling
- RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
- DWI - Leibnitz Institute for Interactive Materials, Forckenbeckstr. 50, 52074, Aachen, Germany
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5
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Haaring R, Kang PW, Lee JW, Lee J, Lee H. Nonconductive Metal Oxide Gas Diffusion Layer for Mitigating Electrowetting during CO 2 Electrolysis. ACS APPLIED MATERIALS & INTERFACES 2024; 16:28731-28741. [PMID: 38781021 DOI: 10.1021/acsami.4c05467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Gas diffusion electrodes (GDEs) are extensively used for high current density electrochemical CO2 electrolysis (ECO2R), enabled by significantly reducing mass transfer resistance of CO2 to the catalyst layer. Conventionally, these GDEs are based upon hydrophobic carbon-based gas-diffusion layers (GDLs) that facilitate the gas transport; however, these supports are prone to flood with electrolyte during electrolysis. This potential-induced flooding, known as electrowetting, is related to the inherent conductivity of carbon and limits the activity of ECO2R. To investigate the effect of electrical conductivity more carefully, a GDE is constructed based on a Cu mesh with a nonconductive microporous GDL applied to this substrate, the latter composed of a mixture of metal oxide and polytetrafluoroethylene. With alumina as the metal oxide, a stable operation is obtained at -200 mA cm-2 with 70% selectivity for ECO2R (with over half toward C2+ products) without flooding as observed by in situ microscopy. On the contrary, with a Vulcan carbon-based GDL, the initial activity is rapidly lost as severe flooding ensues. It is reasoned that electrowetting is averted by virtue of the nonconductive nature of alumina, providing a new perspective on alternative GDL compositions and their influence on ECO2R performance.
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Affiliation(s)
- Robert Haaring
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Phil Woong Kang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Jae Won Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Junpyo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Hyunjoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
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6
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Ligthart NEG, Prats Vergel G, Padding JT, Vermaas DA. Practical potential of suspension electrodes for enhanced limiting currents in electrochemical CO 2 reduction. ENERGY ADVANCES 2024; 3:841-853. [PMID: 38645976 PMCID: PMC11025499 DOI: 10.1039/d3ya00611e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/11/2024] [Indexed: 04/23/2024]
Abstract
CO2 conversion is an important part of the transition towards clean fuels and chemicals. However, low solubility of CO2 in water and its slow diffusion cause mass transfer limitations in aqueous electrochemical CO2 reduction. This significantly limits the partial current densities towards any desired CO2-reduction product. We propose using flowable suspension electrodes to spread the current over a larger volume and alleviate mass transfer limitations, which could allow high partial current densities for CO2 conversion even in aqueous environments. To identify the requirements for a well-performing suspension electrode, we use a transmission line model to simulate the local electric and ionic current distributions throughout a channel and show that the electrocatalysis is best distributed over the catholyte volume when the electric, ionic and charge transfer resistances are balanced. In addition, we used electrochemical impedance spectroscopy to measure the different resistance contributions and correlated the results with rheology measurements to show that particle size and shape impact the ever-present trade-off between conductivity and flowability. We combine the modelling and experimental results to evaluate which carbon type is most suitable for use in a suspension electrode for CO2 reduction, and predict a good reaction distribution throughout activated carbon and carbon black suspensions. Finally, we tested several suspension electrodes in a CO2 electrolyzer. Even though mass transport limitations should be reduced, the CO partial current densities are capped at 2.8 mA cm-2, which may be due to engineering limitations. We conclude that using suspension electrodes is challenging for sensitive reactions like CO2 reduction, and may be more suitable for use in other electrochemical conversion reactions suffering from mass transfer limitations that are less affected by competing reactions and contaminations.
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Affiliation(s)
- Nathalie E G Ligthart
- Department of Chemical Engineering, Delft University of Technology 2629 HZ Delft The Netherlands
| | - Gerard Prats Vergel
- Department of Chemical Engineering, Delft University of Technology 2629 HZ Delft The Netherlands
| | - Johan T Padding
- Department of Process and Energy, Delft University of Technology Leeghwaterstraat 39 2628 CB Delft The Netherlands
| | - David A Vermaas
- Department of Chemical Engineering, Delft University of Technology 2629 HZ Delft The Netherlands
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7
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O'Brien CP, Miao RK, Shayesteh Zeraati A, Lee G, Sargent EH, Sinton D. CO 2 Electrolyzers. Chem Rev 2024; 124:3648-3693. [PMID: 38518224 DOI: 10.1021/acs.chemrev.3c00206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024]
Abstract
CO2 electrolyzers have progressed rapidly in energy efficiency and catalyst selectivity toward valuable chemical feedstocks and fuels, such as syngas, ethylene, ethanol, and methane. However, each component within these complex systems influences the overall performance, and the further advances needed to realize commercialization will require an approach that considers the whole process, with the electrochemical cell at the center. Beyond the cell boundaries, the electrolyzer must integrate with upstream CO2 feeds and downstream separation processes in a way that minimizes overall product energy intensity and presents viable use cases. Here we begin by describing upstream CO2 sources, their energy intensities, and impurities. We then focus on the cell, the most common CO2 electrolyzer system architectures, and each component within these systems. We evaluate the energy savings and the feasibility of alternative approaches including integration with CO2 capture, direct conversion of flue gas and two-step conversion via carbon monoxide. We evaluate pathways that minimize downstream separations and produce concentrated streams compatible with existing sectors. Applying this comprehensive upstream-to-downstream approach, we highlight the most promising routes, and outlook, for electrochemical CO2 reduction.
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Affiliation(s)
- Colin P O'Brien
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Rui Kai Miao
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Ali Shayesteh Zeraati
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Geonhui Lee
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada
| | - Edward H Sargent
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Department of Electrical and Computer Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - David Sinton
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
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8
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Lai W, Qiao Y, Wang Y, Huang H. Stability Issues in Electrochemical CO 2 Reduction: Recent Advances in Fundamental Understanding and Design Strategies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2306288. [PMID: 37562821 DOI: 10.1002/adma.202306288] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/08/2023] [Indexed: 08/12/2023]
Abstract
Electrochemical CO2 reduction reaction (CO2 RR) offers a promising approach to close the anthropogenic carbon cycle and store intermittent renewable energy in fuels or chemicals. On the path to commercializing this technology, achieving the long-term operation stability is a central requirement but still confronts challenges. This motivates to organize the present review to systematically discuss the stability issue of CO2 RR. This review starts from the fundamental understanding on the destabilization mechanisms of CO2 RR, with focus on the degradation of electrocatalyst and change of reaction microenvironment during continuous electrolysis. Subsequently, recent efforts on catalyst design to stabilize the active sites are summarized, where increasing atomic binding strength to resist surface reconstruction is highlighted. Next, the optimization of electrolysis system to enhance the operation stability by maintaining reaction microenvironment especially mitigating flooding and carbonate problems is demonstrated. The manipulation on operation conditions also enables to prolong CO2 RR lifespan through recovering catalytically active sites and mass transport process. This review finally ends up by indicating the challenges and future opportunities.
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Affiliation(s)
- Wenchuan Lai
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
- College of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, P. R. China
| | - Yan Qiao
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Yanan Wang
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Hongwen Huang
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
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9
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Baumgartner LM, Goryachev A, Koopman CI, Franzen D, Ellendorff B, Turek T, Vermaas DA. Electrowetting limits electrochemical CO 2 reduction in carbon-free gas diffusion electrodes. ENERGY ADVANCES 2023; 2:1893-1904. [PMID: 38013932 PMCID: PMC10634457 DOI: 10.1039/d3ya00285c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/27/2023] [Indexed: 11/29/2023]
Abstract
CO2 electrolysis might be a key process to utilize intermittent renewable electricity for the sustainable production of hydrocarbon chemicals without relying on fossil fuels. Commonly used carbon-based gas diffusion electrodes (GDEs) enable high Faradaic efficiencies for the desired carbon products at high current densities, but have limited stability. In this study, we explore the adaption of a carbon-free GDE from a Chlor-alkali electrolysis process as a cathode for gas-fed CO2 electrolysis. We determine the impact of electrowetting on the electrochemical performance by analyzing the Faradaic efficiency for CO at industrially relevant current density. The characterization of used GDEs with X-ray photoelectron spectroscopy (XPS) and X-Ray diffraction (XRD) reveals a potential-dependent degradation, which can be explained through chemical polytetrafluorethylene (PTFE) degradation and/or physical erosion of PTFE through the restructuring of the silver surface. Our results further suggest that electrowetting-induced flooding lets the Faradaic efficiency for CO drop below 40% after only 30 min of electrolysis. We conclude that the effect of electrowetting has to be managed more carefully before the investigated carbon-free GDEs can compete with carbon-based GDEs as cathodes for CO2 electrolysis. Further, not only the conductive phase (such as carbon), but also the binder (such as PTFE), should be carefully selected for stable CO2 reduction.
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Affiliation(s)
| | - Andrey Goryachev
- Department of Chemical Engineering, Delft University of Technology Netherlands
| | - Christel I Koopman
- Department of Chemical Engineering, Delft University of Technology Netherlands
| | - David Franzen
- Institute for Chemical and Electrochemical Process Engineering, Technical University Clausthal Germany
| | - Barbara Ellendorff
- Institute for Chemical and Electrochemical Process Engineering, Technical University Clausthal Germany
| | - Thomas Turek
- Institute for Chemical and Electrochemical Process Engineering, Technical University Clausthal Germany
| | - David A Vermaas
- Department of Chemical Engineering, Delft University of Technology Netherlands
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10
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Lin Z, Han C, O'Connell GEP, Lu X. Recent Progress on Electrode Design for Efficient Electrochemical Valorisation of CO 2 , O 2 , and N 2. Angew Chem Int Ed Engl 2023; 62:e202301435. [PMID: 37246161 DOI: 10.1002/anie.202301435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/23/2023] [Accepted: 05/24/2023] [Indexed: 05/30/2023]
Abstract
CO2 reduction, two-electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value-added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g., its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL).
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Affiliation(s)
- Zeheng Lin
- Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Chen Han
- Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - George E P O'Connell
- Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Xunyu Lu
- Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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11
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Baumgartner L, Kahn A, Hoogland M, Bleeker J, Jager WF, Vermaas DA. Direct Imaging of Local pH Reveals Bubble-Induced Mixing in a CO 2 Electrolyzer. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2023; 11:10430-10440. [PMID: 37476421 PMCID: PMC10354799 DOI: 10.1021/acssuschemeng.3c01773] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 06/07/2023] [Indexed: 07/22/2023]
Abstract
Electrochemical CO2 reduction poses a promising pathway to produce hydrocarbon chemicals and fuels without relying on fossil fuels. Gas diffusion electrodes allow high selectivity for desired carbon products at high current density by ensuring a sufficient CO2 mass transfer rate to the catalyst layer. In addition to CO2 mass transfer, the product selectivity also strongly depends on the local pH at the catalyst surface. In this work, we directly visualize for the first time the two-dimensional (2D) pH profile in the catholyte channel of a gas-fed CO2 electrolyzer equipped with a bipolar membrane. The pH profile is imaged with operando fluorescence lifetime imaging microscopy (FLIM) using a pH-sensitive quinolinium-based dye. We demonstrate that bubble-induced mixing plays an important role in the Faradaic efficiency. Our concentration measurements show that the pH at the catalyst remains lower at -100 mA cm-2 than at -10 mA cm-2, implying that bubble-induced advection outweighs the additional OH- flux at these current densities. We also prove that the pH buffering effect of CO2 from the gas feed and dissolved CO2 in the catholyte prevents the gas diffusion electrode from becoming strongly alkaline. Our findings suggest that gas-fed CO2 electrolyzers with a bipolar membrane and a flowing catholyte are promising designs for scale-up and high-current-density operation because they are able to avoid extreme pH values in the catalyst layer.
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Affiliation(s)
- Lorenz
M. Baumgartner
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Aron Kahn
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Maxime Hoogland
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jorrit Bleeker
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Wolter F. Jager
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - David A. Vermaas
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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12
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Samu AA, Szenti I, Kukovecz Á, Endrődi B, Janáky C. Systematic screening of gas diffusion layers for high performance CO 2 electrolysis. Commun Chem 2023; 6:41. [PMID: 36828885 PMCID: PMC9958001 DOI: 10.1038/s42004-023-00836-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 02/08/2023] [Indexed: 02/26/2023] Open
Abstract
Certain industrially relevant performance metrics of CO2 electrolyzers have already been approached in recent years. The energy efficiency of CO2 electrolyzers, however, is yet to be improved, and the reasons behind performance fading must be uncovered. The performance of the electrolyzer cells is strongly affected by their components, among which the gas diffusion electrode is one of the most critical elements. To understand which parameters of the gas diffusion layers (GDLs) affect the cell performance the most, we compared commercially available GDLs in the electrochemical reduction of CO2 to CO, under identical, fully controlled experimental conditions. By systematically screening the most frequently used GDLs and their counterparts differing in only one parameter, we tested the influence of the microporous layer, the polytetrafluoroethylene content, the thickness, and the orientation of the carbon fibers of the GDLs. The electrochemical results were correlated to different physical/chemical parameters of the GDLs, such as their hydrophobicity and surface cracking.
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Affiliation(s)
- Angelika Anita Samu
- grid.9008.10000 0001 1016 9625Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged, H-6720 Hungary ,eChemicles Zrt, Alsó Kikötő sor 11, Szeged, H-6726 Hungary
| | - Imre Szenti
- grid.9008.10000 0001 1016 9625Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Square 1, Szeged, H-6720 Hungary
| | - Ákos Kukovecz
- grid.9008.10000 0001 1016 9625Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Square 1, Szeged, H-6720 Hungary
| | - Balázs Endrődi
- Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged, H-6720, Hungary.
| | - Csaba Janáky
- Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged, H-6720, Hungary. .,eChemicles Zrt, Alsó Kikötő sor 11, Szeged, H-6726, Hungary.
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13
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Blake JW, Konderla V, Baumgartner LM, Vermaas DA, Padding JT, Haverkort JW. Inhomogeneities in the Catholyte Channel Limit the Upscaling of CO 2 Flow Electrolysers. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2023; 11:2840-2852. [PMID: 36844750 PMCID: PMC9945194 DOI: 10.1021/acssuschemeng.2c06129] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The use of gas diffusion electrodes that supply gaseous CO2 directly to the catalyst layer has greatly improved the performance of electrochemical CO2 conversion. However, reports of high current densities and Faradaic efficiencies primarily come from small lab scale electrolysers. Such electrolysers typically have a geometric area of 5 cm2, while an industrial electrolyser would require an area closer to 1 m2. The difference in scales means that many limitations that manifest only for larger electrolysers are not captured in lab scale setups. We develop a 2D computational model of both a lab scale and upscaled CO2 electrolyser to determine performance limitations at larger scales and how they compare to the performance limitations observed at the lab scale. We find that for the same current density larger electrolysers exhibit much greater reaction and local environment inhomogeneity. Increasing catalyst layer pH and widening concentration boundary layers of the KHCO3 buffer in the electrolyte channel lead to higher activation overpotential and increased parasitic loss of reactant CO2 to the electrolyte solution. We show that a variable catalyst loading along the direction of the flow channel may improve the economics of a large scale CO2 electrolyser.
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Affiliation(s)
- Joseph W. Blake
- Department
of Process and Energy, Delft University
of Technology, Leeghwaterstraat 39, 2628 CBDelft, The Netherlands
| | - Vojtěch Konderla
- Department
of Chemical Engineering, Delft University
of Technology, 2629 HZDelft, Netherlands
| | - Lorenz M. Baumgartner
- Department
of Chemical Engineering, Delft University
of Technology, 2629 HZDelft, Netherlands
| | - David A. Vermaas
- Department
of Chemical Engineering, Delft University
of Technology, 2629 HZDelft, Netherlands
| | - Johan T. Padding
- Department
of Process and Energy, Delft University
of Technology, Leeghwaterstraat 39, 2628 CBDelft, The Netherlands
| | - J. W. Haverkort
- Department
of Process and Energy, Delft University
of Technology, Leeghwaterstraat 39, 2628 CBDelft, The Netherlands
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14
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Sassenburg M, Kelly M, Subramanian S, Smith WA, Burdyny T. Zero-Gap Electrochemical CO 2 Reduction Cells: Challenges and Operational Strategies for Prevention of Salt Precipitation. ACS ENERGY LETTERS 2023; 8:321-331. [PMID: 36660368 PMCID: PMC9841607 DOI: 10.1021/acsenergylett.2c01885] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Salt precipitation is a problem in electrochemical CO2 reduction electrolyzers that limits their long-term durability and industrial applicability by reducing the active area, causing flooding and hindering gas transport. Salt crystals form when hydroxide generation from electrochemical reactions interacts homogeneously with CO2 to generate substantial quantities of carbonate. In the presence of sufficient electrolyte cations, the solubility limits of these species are reached, resulting in "salting out" conditions in cathode compartments. Detrimental salt precipitation is regularly observed in zero-gap membrane electrode assemblies, especially when operated at high current densities. This Perspective briefly discusses the mechanisms for salt formation, and recently reported strategies for preventing or reversing salt formation in zero-gap CO2 reduction membrane electrode assemblies. We link these approaches to the solubility limit of potassium carbonate within the electrolyzer and describe how each strategy separately manipulates water, potassium, and carbonate concentrations to prevent (or mitigate) salt formation.
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Affiliation(s)
- Mark Sassenburg
- Materials
for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, 2629 ZHDelft, The Netherlands
| | - Maria Kelly
- Department
of Chemical and Biological Engineering and Renewable and Sustainable
Energy Institute (RASEI), University of
Colorado Boulder, Boulder, Colorado80303, United States
- National
Renewable Energy Laboratory, Golden, Colorado80401, United States
| | - Siddhartha Subramanian
- Materials
for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, 2629 ZHDelft, The Netherlands
| | - Wilson A. Smith
- Materials
for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, 2629 ZHDelft, The Netherlands
- Department
of Chemical and Biological Engineering and Renewable and Sustainable
Energy Institute (RASEI), University of
Colorado Boulder, Boulder, Colorado80303, United States
- National
Renewable Energy Laboratory, Golden, Colorado80401, United States
| | - Thomas Burdyny
- Materials
for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, 2629 ZHDelft, The Netherlands
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15
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Baumgartner L, Koopman CI, Forner-Cuenca A, Vermaas DA. When Flooding Is Not Catastrophic-Woven Gas Diffusion Electrodes Enable Stable CO 2 Electrolysis. ACS APPLIED ENERGY MATERIALS 2022; 5:15125-15135. [PMID: 36590882 PMCID: PMC9795489 DOI: 10.1021/acsaem.2c02783] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Electrochemical CO2 reduction has the potential to use excess renewable electricity to produce hydrocarbon chemicals and fuels. Gas diffusion electrodes (GDEs) allow overcoming the limitations of CO2 mass transfer but are sensitive to flooding from (hydrostatic) pressure differences, which inhibits upscaling. We investigate the effect of the flooding behavior on the CO2 reduction performance. Our study includes six commercial gas diffusion layer materials with different microstructures (carbon cloth and carbon paper) and thicknesses coated with a Ag catalyst and exposed to differential pressures corresponding to different flow regimes (gas breakthrough, flow-by, and liquid breakthrough). We show that physical electrowetting further limits the flow-by regime at commercially relevant current densities (≥200 mA cm-2), which reduces the Faradaic efficiency for CO (FECO) for most carbon papers. However, the carbon cloth GDE maintains its high CO2 reduction performance despite being flooded with the electrolyte due to its bimodal pore structure. Exposed to pressure differences equivalent to 100 cm height, the carbon cloth is able to sustain an average FECO of 69% at 200 mA cm-2 even when the liquid continuously breaks through. CO2 electrolyzers with carbon cloth GDEs are therefore promising for scale-up because they enable high CO2 reduction efficiency while tolerating a broad range of flow regimes.
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Affiliation(s)
- Lorenz
M. Baumgartner
- Department
of Chemical Engineering, Delft University
of Technology, Van der
Maasweg 9, 2629 HZDelft, Netherlands
| | - Christel I. Koopman
- Department
of Chemical Engineering, Delft University
of Technology, Van der
Maasweg 9, 2629 HZDelft, Netherlands
| | - Antoni Forner-Cuenca
- Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, Het Kranenveld 14, 5612 AZEindhoven, Netherlands
| | - David A. Vermaas
- Department
of Chemical Engineering, Delft University
of Technology, Van der
Maasweg 9, 2629 HZDelft, Netherlands
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16
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Bagemihl I, Bhatraju C, van Ommen JR, van Steijn V. Electrochemical Reduction of CO 2 in Tubular Flow Cells under Gas-Liquid Taylor Flow. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2022; 10:12580-12587. [PMID: 36189111 PMCID: PMC9516770 DOI: 10.1021/acssuschemeng.2c03038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Electrochemical reduction of CO2 using renewable energy is a promising avenue for sustainable production of bulk chemicals. However, CO2 electrolysis in aqueous systems is severely limited by mass transfer, leading to low reactor performance insufficient for industrial application. This paper shows that structured reactors operated under gas-liquid Taylor flow can overcome these limitations and significantly improve the reactor performance. This is achieved by reducing the boundary layer for mass transfer to the thin liquid film between the CO2 bubbles and the electrode. This work aims to understand the relationship between process conditions, mass transfer, and reactor performance by developing an easy-to-use analytical model. We find that the film thickness and the volume ratio of CO2/electrolyte fed to the reactor significantly affect the current density and the faradaic efficiency. Additionally, we find industrially relevant performance when operating the reactor at an elevated pressure beyond 5 bar. We compare our predictions with numerical simulations based on the unit cell approach, showing good agreement for a large window of operating parameters, illustrating when the easy-to-use predictive expressions for the current density and faradaic efficiency can be applied.
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17
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Delafontaine L, Murphy E, Guo S, Liu Y, Asset T, Huang Y, Chen J, Zenyuk IV, Pan X, Atanassov P. Synergistic Electrocatalytic Syngas Production from Carbon Dioxide by Bi‐Metallic Atomically Dispersed Catalysts. ChemElectroChem 2022. [DOI: 10.1002/celc.202200647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Laurent Delafontaine
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Eamonn Murphy
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Shengyuan Guo
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Yuanchao Liu
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Tristan Asset
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Ying Huang
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Jiazhe Chen
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Iryna V. Zenyuk
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
- Department of Materials Science and Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
| | - Xiaoqing Pan
- Department of Materials Science and Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
- Department of Physics and Astronomy University of California Irvine California 92697 USA
| | - Plamen Atanassov
- Department of Chemical and Biomolecular Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
- Department of Materials Science and Engineering National Fuel Cell Research Center University of California Irvine California 92697 USA
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18
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Samu A, Kormányos A, Kecsenovity E, Szilágyi N, Endrődi B, Janáky C. Intermittent Operation of CO 2 Electrolyzers at Industrially Relevant Current Densities. ACS ENERGY LETTERS 2022; 7:1859-1861. [PMID: 35601629 PMCID: PMC9112675 DOI: 10.1021/acsenergylett.2c00923] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 04/29/2022] [Indexed: 05/30/2023]
Abstract
We demonstrate the dynamic operation of CO2 electrolyzer cells, with a power input mimicking the output of a solar photovoltaic power plant. The zero-gap design ensured efficient intermittent operation for a week, while avoiding significant performance loss.
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Affiliation(s)
- Angelika
A. Samu
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
- eChemicles
Zrt, Alsó Kikötő
sor 11, Szeged H-6726, Hungary
| | - Attila Kormányos
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
| | - Egon Kecsenovity
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
| | - Norbert Szilágyi
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
| | - Balázs Endrődi
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
| | - Csaba Janáky
- Department
of Physical Chemistry and Materials Science, University of Szeged, Rerrich Square 1, Szeged H-6720, Hungary
- eChemicles
Zrt, Alsó Kikötő
sor 11, Szeged H-6726, Hungary
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19
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Erbil HY. Precursor film formation on catalyst–electrolyte–gas boundaries during CO 2 electroreduction with gas diffusion electrodes. Catal Sci Technol 2022. [DOI: 10.1039/d2cy01576e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thin and long layers of catholyte precursor films spread near triple-phase boundaries on composite catalysts containing hydrophobic materials. Dissolved CO2 molecules in the precursor films reduce on the composite catalyst surface without depletion.
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