Sustainable Hydrogen Production from Seawater Electrolysis
Lead Research Organisation:
Loughborough University
Department Name: Chemical Engineering
Abstract
Electrochemistry enables direct conversion between electrical and chemical energy with high efficiency, and is a key to achieving net zero. An exciting electrochemical technology is the hydrogen-oxygen (H2-O2) fuel cell that produces electricity at high efficiency with only clean water as the byproduct. A green and sustainable route for H2 production to support this technology is water electrolysis using renewable or excess electricity; however, it is an energetically uphill process involving the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. Whilst the 2-electron HER is relatively facile, the 4-electron OER is particularly sluggish and requires noble metals (Ir, Ru) as catalysts under acidic conditions. Nevertheless, recently significant progress has been made (including some adventurous work by the applicant and their collaborators) towards more efficient OER under alkaline conditions, where non-noble metal catalysts such as transition metal (Ni, Fe) layered double hydroxides (LDHs) were effectively used.
Notably, for water electrolysis to be used to store (as H2) a substantial portion of the world's energy, water distribution issues will arise as vast amounts of purified water will be needed. On the other hand, seawater is the most abundant aqueous electrolyte feedstock on Earth, but its implementation in the water-splitting process presents many challenges, especially for the anodic reaction. The most serious challenges in seawater electrolysis are posed by the chloride anions (around 3% NaCl in seawater by weight). Under acidic conditions, the OER equilibrium potential (1.23 V) is only slightly (130 mV) lower than that (1.36 V) of the chlorine evolution reaction (ClER); and OER as a 4-electron reaction requires a high overpotential while ClER is a facile 2-electron reaction with a kinetic advantage, thus CIER can compete with OER.
However, in alkaline conditions, the equilibrium potential of OER is significantly shifted lower, e.g., 0.40 V at pH=14; while that of ClER does not change so much (1.36 V) but now the hypochlorite (ClO-) formation from chloride oxidation reaction (ClOR) must be considered as the latter has a relatively lower equilibrium potential of 0.88 V at pH=14; clearly now there is a significant difference of 480 mV in potential domain for OER to work before ClOR occurs.
Within the above context, this exciting project aims to draw together the nascent work on new catalysts (including surface structures and layers) for the OER anode and HER cathode, the anion exchange membrane, membrane-electrode-assembly and reactor system development, in order to determine the feasibility of formulating low-cost and high performance (active and durable) electrodes and membrane-electrode-assemblies (MEAs) for a cost-effective and scalable seawater electrolyser for sustainable hydrogen production with the maximum resource and energy efficiencies.
The proposed work is highly ambitious and high risk, as seawater electrolysis is very attractive but extremely challenging, ranging from competitive chloride oxidation to corrosive environments, which require highly selective electrocatalysts together with good stability at material level, and well-engineered electrodes and interfaces to facilitate mass transport (gas bubble removal) to enable high current density to be sustained at reactor level. However, if this feasibility research is successful, it will be extremely rewarding as it opens a new paradigm for low cost, large scale, and truly sustainable green hydrogen production for delivering sustainable net zero for the UK and beyond.
Notably, for water electrolysis to be used to store (as H2) a substantial portion of the world's energy, water distribution issues will arise as vast amounts of purified water will be needed. On the other hand, seawater is the most abundant aqueous electrolyte feedstock on Earth, but its implementation in the water-splitting process presents many challenges, especially for the anodic reaction. The most serious challenges in seawater electrolysis are posed by the chloride anions (around 3% NaCl in seawater by weight). Under acidic conditions, the OER equilibrium potential (1.23 V) is only slightly (130 mV) lower than that (1.36 V) of the chlorine evolution reaction (ClER); and OER as a 4-electron reaction requires a high overpotential while ClER is a facile 2-electron reaction with a kinetic advantage, thus CIER can compete with OER.
However, in alkaline conditions, the equilibrium potential of OER is significantly shifted lower, e.g., 0.40 V at pH=14; while that of ClER does not change so much (1.36 V) but now the hypochlorite (ClO-) formation from chloride oxidation reaction (ClOR) must be considered as the latter has a relatively lower equilibrium potential of 0.88 V at pH=14; clearly now there is a significant difference of 480 mV in potential domain for OER to work before ClOR occurs.
Within the above context, this exciting project aims to draw together the nascent work on new catalysts (including surface structures and layers) for the OER anode and HER cathode, the anion exchange membrane, membrane-electrode-assembly and reactor system development, in order to determine the feasibility of formulating low-cost and high performance (active and durable) electrodes and membrane-electrode-assemblies (MEAs) for a cost-effective and scalable seawater electrolyser for sustainable hydrogen production with the maximum resource and energy efficiencies.
The proposed work is highly ambitious and high risk, as seawater electrolysis is very attractive but extremely challenging, ranging from competitive chloride oxidation to corrosive environments, which require highly selective electrocatalysts together with good stability at material level, and well-engineered electrodes and interfaces to facilitate mass transport (gas bubble removal) to enable high current density to be sustained at reactor level. However, if this feasibility research is successful, it will be extremely rewarding as it opens a new paradigm for low cost, large scale, and truly sustainable green hydrogen production for delivering sustainable net zero for the UK and beyond.
Publications
Chen L
(2024)
Engineering asymmetric electronic structure of cobalt coordination on CoN3S active sites for high performance oxygen reduction reaction
in Journal of Energy Chemistry
Chen L
(2023)
Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons.
in Proceedings of the National Academy of Sciences of the United States of America
Chen Y
(2023)
FeNC Catalysts Decorated with NiFe 2 O 4 to Enhance Bifunctional Activity for Zn-Air Batteries
in ACS Applied Energy Materials
Cui L
(2024)
Low-cost transition metal-nitrogen-carbon electrocatalysts for the oxygen reduction reaction: operating conditions from aqueous electrolytes to fuel cells
in Sustainable Energy & Fuels
Huang C
(2023)
Enhanced Proton Transport of ß?-Al2O3 Modified by LiAlO2 as a High-Performance Electrolyte for a Low-Temperature Solid Oxide Fuel Cell and an Electrolyzer.
in ACS applied materials & interfaces
Huang L
(2023)
Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte.
in Journal of colloid and interface science
Liu H
(2024)
Constructing Robust 3D Ionomer Networks in the Catalyst Layer to Achieve Stable Water Electrolysis for Green Hydrogen Production.
in ACS applied materials & interfaces
Luo Y
(2025)
Collaborative reconstruction of FeOOH/FeNiCo-LDH heterogeneous nanosheets for enhancing anion exchange membrane seawater electrolysis
in Journal of Materials Chemistry A
Niu HJ
(2025)
Synergistic Atomic Environment Optimization of Nickel-Iron Dual Sites by Co Doping and Cr Vacancy for Electrocatalytic Oxygen Evolution.
in Journal of the American Chemical Society
| Description | We have successfully employed alkaline electrochemistry which enabled us to develop a range of low-cost transitional metal based catalytic electrodes for direct seawater electrolysis to produce hydrogen and oxygen. We have developed a novel method to fabricate nickel (Ni) based electrodes, which demonstrated good performance towards both oxygen evolution reaction (OER) and hydrogen evaluation reaction (HER) and have been used as the bi-functional electrode in the seawater electrolyser. When developing this fabrication method, we carefully designed the individual step, and avoided complex process. This enables our method to be readily scaled up for industrial use. On the more fundamental side, we have employed density functional theory (DFT) and atomistic simulations to investigate intricate mechanisms and have elucidated the hydrogen evolution reaction mechanism on the model Ni5P4 electrocatalyst, notably pinpointing phosphorus as the active sites instead of nickel. This discovery sheds light on the electrocatalytic activity of Ni5P4, promoting the design of efficient and cost-effective electrocatalysts for water splitting. Our computational insights play a pivotal role in unravelling critical aspects of the quantum confinement in enhancing stability of catalysts. Our work represents a significant contribution in addressing the challenges associated with renewable energy production and storage, particularly in advancing knowledge in the complex catalytic mechanisms by employing DFT method. |
| Exploitation Route | Our industrial partner Johnson Matthey could scale up the process and product for their UK and global catalyst manufacturing and sales. Academics and researchers may use this funding to further research and develop the other relevant catalytic electrodes. |
| Sectors | Chemicals Creative Economy Education Energy Environment Leisure Activities including Sports Recreation and Tourism Transport |
| URL | https://pubs.acs.org/doi/10.1021/acs.jpcc.3c00238 |
| Description | The findings have been used in several conferences and workshops that include audiences from industrial sectors, also have been used to showcase our frontier research to the university open days where there were many high school students and parents attended, such have inspired the future generations to the science and engineering research and development. Dr. Y. Li, who is the Research Associate working on this project, delivered an invited oral presentation about our key findings, in the 2023 World Fuel Cell conference (WFCC) at imperial college London in December 2023, with audiences from global academics and industrial R&D leaders. Before this, Dr. Li also presented a poster in the 30th SCI-CSCST Conference at UCL in September 2023, introducing our literature survey results for seawater electrolysis. Prof W. Lin, the PI, delivered a keynote in the 2023 UK Catalysis conference where the low-cost and highly efficient catalysts for the seawater splitting to produce hydrogen and oxygen were reported and the mechanisms at molecular were illustrated. The Keynote talk was received by wider audiences including academics and industrial practitioners. |
| First Year Of Impact | 2023 |
| Sector | Education,Energy |
| Impact Types | Societal |
| Title | CCDC 1527078: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc1n81lk&sid=DataCite |
| Title | CCDC 1527079: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc1n81ml&sid=DataCite |
| Title | CCDC 1527080: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc1n81nm&sid=DataCite |
| Title | CCDC 1550304: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc1p16tr&sid=DataCite |
| Title | CCDC 2124386: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc299llt&sid=DataCite |
| Title | CCDC 2127863: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc29f6rq&sid=DataCite |
| Title | CCDC 2130871: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc29jbsz&sid=DataCite |
| Title | CCDC 2130872: Experimental Crystal Structure Determination |
| Description | Related Article: Lina Chen, Lu Lin, Amit Ranjan Nath, Qin Zhu, Zhixin Chen, Jingjing Wu, Hongjian Wang, Qian Li, Wen-Feng Lin, Jun Zhu, Haiping Xia|2023|Proc.Nat.Acad.Sci.USA|120|e2215900120|doi:10.1073/pnas.2215900120 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc29jbt0&sid=DataCite |
| Title | Supplementary files for S-scheme NaxCoO2/g-C3N4 heterojunction photo-electrocatalysts for water splitting |
| Description | Article abstract: Enabling a highly efficient charge separation on hetero-structural photo-electrocatalyst is crucial to achieve a high efficiency of water splitting technology for sustainable green hydrogen production. Herein, novel S-scheme hetero-structural materials, NaxCoO2/g-C3N4 (x = 0.5, 0.6, and 0.74), have been employed as photo-electrocatalysts for water splitting reaction. Their corresponding overpotential values under irradiation condition with the current density of 10 mA cm-2 were about 590 mV (x = 0.74), 555 mV (x = 0.6) and 710 mV (x = 0.5), respectively. Compared to the dark condition, NaxCoO2/g-C3N4 exhibited lower overpotentials. XPS and in-situ KPFM results further confirmed that an interfacial electric field was formed at the interface of NaxCoO2 and g-C3N4. Under the irradiation condition, the electrons from the conduction band of NCO flow toward to the valence band of CN to form S-scheme heterostructure, which could highly accelerate the reducing capability of CN, hence splitting water to produce hydrogen gas. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_files_for_S-scheme_NaxCoO2_g-C3N4_hete... |
| Title | Supplementary files for Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons |
| Description | Supplementary file for article Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons Abstract Antiaromaticity is extended from aromaticity as a complement to describe the unsaturated cyclic molecules with antiaromatic destabilization. To prepare antiaromatic species is a particularly challenging goal in synthetic chemistry because of the thermodynamic instability of such molecules. Among that, both Hückel and Möbius antiaromatic species have been reported, whereas the Craig one has not been realized to date. Here, we report the first example of planar Craig antiaromatic species. Eight Craig antiaromatic compounds were synthesized by deprotonation-induced reduction process and were fully characterized as follows. Single-crystal X-ray crystallography showed that these complexes have planar structures composed of fused five-membered rings with clearly alternating carbon-carbon bond lengths. In addition, proton NMR (1H NMR) spectroscopy in these structures showed distinctive upfield shifts of the proton peaks to the range of antiaromatic peripheral hydrogens. Experimental spectroscopy observations, along with density-functional theory (DFT) calculations, provided evidence for the Craig antiaromaticity of these complexes. Further study experimentally and theoretically revealed that the strong exothermicity of the acid-base neutralization process was the driving force for this challenging transformation forming Craig antiaromatic species. Our findings complete a full cycle of aromatic chemistry, opening an avenue for the development of new class of antiaromatic systems. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_files_for_Synthesis_and_characterizati... |
| Title | Supplementary information files for "S-scheme p-n junction Na0.6CoO2/g-C3N4 heterostructure as an efficient photocatalyst for green hydrogen production: fabrication, characterization and mechanisms" |
| Description | Supplementary information files for article "S-scheme p-n junction Na0.6CoO2/g-C3N4 heterostructure as an efficient photocatalyst for green hydrogen production: fabrication, characterization and mechanisms"Probing the spatial separation and transport process of photogenerated charges at nanoscale interfaces is essential for understanding catalytic reaction mechanisms on heterostructure photocatalysts. Here, we developed a p-n junction Na0.6CoO2/g-C3N4 S-scheme photocatalyst via electrostatic self-assembly technology. A significant hydrogen production rate of ~ 0.294 mmol g-1 h-1 was achieved on the optimal Na0.6CoO2/g-C3N4, which was ten times higher than that of pure g-C3N4. In-situ XPS shows that the electrons in Na0.6CoO2/g-C3N4 had different flow directions without and with illumination, demonstrating a built-in electric field being formed through Na0.6CoO2 and g-C3N4 interaction. DFT calculations and ultraviolet photoelectron spectroscopy verified that g-C3N4 and Na0.6CoO2 possess the energy band structures conforming to the heterostructure of S-scheme. In-situ Kelvin probe microscope studies show that Na0.6CoO2 and g-C3N4 both have a self-induced electric field effect, and their combination significantly strengthens the built-in electric field and improves the space separation of photogenerated electrons. Compared with the change of the surface photovoltage of g-C3N4 (60 mV) and Na0.6CoO2 (-30 mV), the average surface contact potential difference of Na0.6CoO2/g-C3N4 reached 320 mV, yielding a higher efficiency of photogenerated electron separation. This work also provides direct evidence on the existence of a built-in electric field and an electron flow direction for heterostructure photocatalyst materials.© The Authors, CC BY 4.0 |
| Type Of Material | Database/Collection of data |
| Year Produced | 2025 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_S-scheme_p-n_jun... |
| Title | Supplementary information files for A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessment |
| Description | © the Authors CC-BY 4.0Supplementary files for article A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessmentCO2 capture and utilization are an effective solution to the problem of CO2 emissions, and a combination of ammonia-based CO2 capture and its use for methanol production is a highly feasible strategy. However, the uses of conventional technologies have resulted in a high demand for energy, with limited use of hydrogen. To address these problems, an innovative strategy is proposed and demonstrated in this study that enhances the conventional design, i.e., to use ammonia-based CO2 capture with double tower absorption and solvent split, along with wet hydrogen for methanol production at industrial scale. The process is further improved through a multi-criteria assessment that considered the CO2 capture rate, NH3 loss rate, CO2 conversion rate, and energy saving factors, in which the latter is based on two components, namely the reboiler duty and the condenser duty. Moreover, an exergy analysis method is used to optimize the improved process, and a highly efficient integrated process is finally established. It has been found that the use of a double-tower absorption process ensures high rates of CO2 capture and low rates of NH3 loss. Additionally, adjusting the molar ratio of H2 to CO2 leads to an impressive 8% increase in the CO2 conversion rate, reaching 25%. In terms of energy savings, the average reboiler duty was reduced from 13.39 to 11.85 MJ/kgCO2, i.e., by 11.50%; while the condenser duty was reduced by 11.36%; both contributed to the overall energy savings. In the I-ACCMP process, the total exergy loss is 437.24 kW, of which the exergy loss of the heat exchangers accounts for 16%, and the desorption tower (DES) accounts for 48%. After optimization, the exergy loss of the heat exchangers decreases from 70.02 kW to 40.45 kW, the exergy loss of the DES decreases from 209.29 kW to 180.91 kW, and the reboiler duty is reduced from 10.60 MJ/kgCO2 to 7.71 MJ/kgCO2. The total exergy loss decreases from 437.24 kW to 372.68 kW, which is a reduction by 14.8%. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_A_strategy_for_C... |
| Title | Supplementary information files for A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessment |
| Description | © the Authors CC-BY 4.0Supplementary files for article A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessmentCO2 capture and utilization are an effective solution to the problem of CO2 emissions, and a combination of ammonia-based CO2 capture and its use for methanol production is a highly feasible strategy. However, the uses of conventional technologies have resulted in a high demand for energy, with limited use of hydrogen. To address these problems, an innovative strategy is proposed and demonstrated in this study that enhances the conventional design, i.e., to use ammonia-based CO2 capture with double tower absorption and solvent split, along with wet hydrogen for methanol production at industrial scale. The process is further improved through a multi-criteria assessment that considered the CO2 capture rate, NH3 loss rate, CO2 conversion rate, and energy saving factors, in which the latter is based on two components, namely the reboiler duty and the condenser duty. Moreover, an exergy analysis method is used to optimize the improved process, and a highly efficient integrated process is finally established. It has been found that the use of a double-tower absorption process ensures high rates of CO2 capture and low rates of NH3 loss. Additionally, adjusting the molar ratio of H2 to CO2 leads to an impressive 8% increase in the CO2 conversion rate, reaching 25%. In terms of energy savings, the average reboiler duty was reduced from 13.39 to 11.85 MJ/kgCO2, i.e., by 11.50%; while the condenser duty was reduced by 11.36%; both contributed to the overall energy savings. In the I-ACCMP process, the total exergy loss is 437.24 kW, of which the exergy loss of the heat exchangers accounts for 16%, and the desorption tower (DES) accounts for 48%. After optimization, the exergy loss of the heat exchangers decreases from 70.02 kW to 40.45 kW, the exergy loss of the DES decreases from 209.29 kW to 180.91 kW, and the reboiler duty is reduced from 10.60 MJ/kgCO2 to 7.71 MJ/kgCO2. The total exergy loss decreases from 437.24 kW to 372.68 kW, which is a reduction by 14.8%. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_A_strategy_for_C... |
| Title | Supplementary information files for Designing high interfacial conduction beyond bulk via engineering the semiconductor-ionic heterostructure CeO2-d/BaZr0.8Y0.2O3 for superior proton conductive fuel cell and water electrolysis applications |
| Description | Supplementary information files for Designing high interfacial conduction beyond bulk via engineering the semiconductor-ionic heterostructure CeO2-d/BaZr0.8Y0.2O3 for superior proton conductive fuel cell and water electrolysis applications Proton ceramic fuel cells (PCFCs) are an emerging clean energy technology; however, a key challenge persists in improving the electrolyte proton conductivity, e.g., around 10-3-10-2 S cm-1 at 600 °C for the well-known BaZr0.8Y0.2O3 (BZY), that is far below the required 0.1 S cm-1. Herein, we report an approach for tuning BZY from low bulk to high interfacial conduction by introducing a semiconductor CeO2-d forming a semiconductor-ionic heterostructure CeO2-d/BZY. The interfacial conduction was identified by a significantly higher conductivity obtained from the BZY grain boundary than that of the bulk and a further improvement from the CeO2-d/BZY which achieved a remarkably high proton conductivity of 0.23 S cm-1. This enabled a high peak power of 845 mW cm-2 at 520 °C from a PCFC using the CeO2-d/BZY as the electrolyte, in strong contrast to the BZY bulk conduction electrolyte with only 229 mW cm-2. Furthermore, the CeO2-d/BZY fuel cell was operated under water electrolysis mode, exhibiting a very high current density output of 3.2 A cm-2 corresponding to a high H2 production rate, under 2.0 V at 520 °C. The band structure and a built-in-field-assisted proton transport mechanism have been proposed and explained. This work demonstrates an efficient way of tuning the electrolyte from low bulk to high interfacial proton conduction to attain sufficient conductivity required for PCFCs, electrolyzers, and other advanced electrochemical energy technologies. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Designing_high_i... |
| Title | Supplementary information files for Designing high interfacial conduction beyond bulk via engineering the semiconductor-ionic heterostructure CeO2-d/BaZr0.8Y0.2O3 for superior proton conductive fuel cell and water electrolysis applications |
| Description | Supplementary information files for Designing high interfacial conduction beyond bulk via engineering the semiconductor-ionic heterostructure CeO2-d/BaZr0.8Y0.2O3 for superior proton conductive fuel cell and water electrolysis applications Proton ceramic fuel cells (PCFCs) are an emerging clean energy technology; however, a key challenge persists in improving the electrolyte proton conductivity, e.g., around 10-3-10-2 S cm-1 at 600 °C for the well-known BaZr0.8Y0.2O3 (BZY), that is far below the required 0.1 S cm-1. Herein, we report an approach for tuning BZY from low bulk to high interfacial conduction by introducing a semiconductor CeO2-d forming a semiconductor-ionic heterostructure CeO2-d/BZY. The interfacial conduction was identified by a significantly higher conductivity obtained from the BZY grain boundary than that of the bulk and a further improvement from the CeO2-d/BZY which achieved a remarkably high proton conductivity of 0.23 S cm-1. This enabled a high peak power of 845 mW cm-2 at 520 °C from a PCFC using the CeO2-d/BZY as the electrolyte, in strong contrast to the BZY bulk conduction electrolyte with only 229 mW cm-2. Furthermore, the CeO2-d/BZY fuel cell was operated under water electrolysis mode, exhibiting a very high current density output of 3.2 A cm-2 corresponding to a high H2 production rate, under 2.0 V at 520 °C. The band structure and a built-in-field-assisted proton transport mechanism have been proposed and explained. This work demonstrates an efficient way of tuning the electrolyte from low bulk to high interfacial proton conduction to attain sufficient conductivity required for PCFCs, electrolyzers, and other advanced electrochemical energy technologies. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Designing_high_i... |
| Title | Supplementary information files for Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons |
| Description | Supplementary files for article Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons Abstract Antiaromaticity is extended from aromaticity as a complement to describe the unsaturated cyclic molecules with antiaromatic destabilization. To prepare antiaromatic species is a particularly challenging goal in synthetic chemistry because of the thermodynamic instability of such molecules. Among that, both Hückel and Möbius antiaromatic species have been reported, whereas the Craig one has not been realized to date. Here, we report the first example of planar Craig antiaromatic species. Eight Craig antiaromatic compounds were synthesized by deprotonation-induced reduction process and were fully characterized as follows. Single-crystal X-ray crystallography showed that these complexes have planar structures composed of fused five-membered rings with clearly alternating carbon-carbon bond lengths. In addition, proton NMR (1H NMR) spectroscopy in these structures showed distinctive upfield shifts of the proton peaks to the range of antiaromatic peripheral hydrogens. Experimental spectroscopy observations, along with density-functional theory (DFT) calculations, provided evidence for the Craig antiaromaticity of these complexes. Further study experimentally and theoretically revealed that the strong exothermicity of the acid-base neutralization process was the driving force for this challenging transformation forming Craig antiaromatic species. Our findings complete a full cycle of aromatic chemistry, opening an avenue for the development of new class of antiaromatic systems. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_files_for_Synthesis_and_characterizati... |
| Title | Supplementary information files for Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons |
| Description | Supplementary files for article Synthesis and characterization of Craig-type antiaromatic species with [4n + 2] p electrons Abstract Antiaromaticity is extended from aromaticity as a complement to describe the unsaturated cyclic molecules with antiaromatic destabilization. To prepare antiaromatic species is a particularly challenging goal in synthetic chemistry because of the thermodynamic instability of such molecules. Among that, both Hückel and Möbius antiaromatic species have been reported, whereas the Craig one has not been realized to date. Here, we report the first example of planar Craig antiaromatic species. Eight Craig antiaromatic compounds were synthesized by deprotonation-induced reduction process and were fully characterized as follows. Single-crystal X-ray crystallography showed that these complexes have planar structures composed of fused five-membered rings with clearly alternating carbon-carbon bond lengths. In addition, proton NMR (1H NMR) spectroscopy in these structures showed distinctive upfield shifts of the proton peaks to the range of antiaromatic peripheral hydrogens. Experimental spectroscopy observations, along with density-functional theory (DFT) calculations, provided evidence for the Craig antiaromaticity of these complexes. Further study experimentally and theoretically revealed that the strong exothermicity of the acid-base neutralization process was the driving force for this challenging transformation forming Craig antiaromatic species. Our findings complete a full cycle of aromatic chemistry, opening an avenue for the development of new class of antiaromatic systems. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_files_for_Synthesis_and_characterizati... |
| Title | Supplementary information files for: Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte |
| Description | Supplementary files for article Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte. Having a highly-conductive protonic electrolyte is an essential requirement of developing solid ceramic fuel cell (SCFC) operated below 600 °C. Proton transport in solid electrolyte structure occurs via a bulk conduction mechanism in conventional SCFC, which may not be so efficient; therefore we have developed a fast proton conducting NaAlO2/LiAlO2 (NAO-LAO) heterostructure electrolyte, achieving the ionic conductivity of 0.23 S cm-1 thanks to its rich cross-linked solid-liquid interfaces; the SCFC employing this new developed electrolyte showed a maximum power density of 844 mW cm-2 at 550 °C, and the fuel cell could still operate at even lower temperatures down to 370 °C, although the output reduced to 90 mW cm-2. The proton-hydration liquid layer promoted the formation of cross-linked solid-liquid interfaces in the NAO-LAO electrolyte, which promoted the construction of solid-liquid hybrid proton transportation channels and effectively reduced polarization loss, leading to high proton conduction at even lower temperatures. This work provides an efficient design approach for developing enabling electrolytes with high proton conductivity for SCFCs to be operated at relatively lower temperatures (300-600 °C) than traditional solid oxide fuel cells which operate above 750 °C. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Cross-linked_sol... |
| Title | Supplementary information files for: Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte |
| Description | Supplementary files for article Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte. Having a highly-conductive protonic electrolyte is an essential requirement of developing solid ceramic fuel cell (SCFC) operated below 600 °C. Proton transport in solid electrolyte structure occurs via a bulk conduction mechanism in conventional SCFC, which may not be so efficient; therefore we have developed a fast proton conducting NaAlO2/LiAlO2 (NAO-LAO) heterostructure electrolyte, achieving the ionic conductivity of 0.23 S cm-1 thanks to its rich cross-linked solid-liquid interfaces; the SCFC employing this new developed electrolyte showed a maximum power density of 844 mW cm-2 at 550 °C, and the fuel cell could still operate at even lower temperatures down to 370 °C, although the output reduced to 90 mW cm-2. The proton-hydration liquid layer promoted the formation of cross-linked solid-liquid interfaces in the NAO-LAO electrolyte, which promoted the construction of solid-liquid hybrid proton transportation channels and effectively reduced polarization loss, leading to high proton conduction at even lower temperatures. This work provides an efficient design approach for developing enabling electrolytes with high proton conductivity for SCFCs to be operated at relatively lower temperatures (300-600 °C) than traditional solid oxide fuel cells which operate above 750 °C. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Cross-linked_sol... |
| Title | Supplementary information files for: Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells |
| Description | Supplementary files for article: Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells Ion transport in solid oxide electrolytes is a key process involved in advanced green energy conversion devices such as solid oxide fuel cells (SOFCs). Conventional SOFC electrolytes require a high operational temperature (over 700 °C) to maintain considerable bulk and grain boundary diffusion of the ions to enable sufficient ionic conductivity for efficient fuel cell operation. The present study explores a novel ion conduction expressway in an amorphous/crystalline heterostructure, La0·8Sr0·2Al0·8Zn0·2O3-d (LSAZ), which can boost the mobility of ions at a relatively low temperature (450-550 °C) for SOFCs. The LSAZ heterostructure includes an insulating perovskite core and a superionic-conducting amorphous surface layer. This electrolyte exhibits a superior conductivity of 0.319 S cm-1 at 550 °C, and it is employed in a SOFC which demonstrates a remarkable performance of 1296 mW cm-2 at 550 °C, which is 300 times higher than a SOFC with the LSAZ being densified at 1400 °C for 10 h. A superionic conducting amorphous surface layer enriched by high oxygen vacancy defects facilitates ionic conduction along the grain boundary and interfaces between the nanoparticles of LSAZ. Our finding provides an efficient way to design advanced highly conductive electrolytes for solid oxide fuel cells to be operated at reduced temperatures. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Fast_ion-conduct... |
| Title | Supplementary information files for: Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells |
| Description | Supplementary files for article: Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells Ion transport in solid oxide electrolytes is a key process involved in advanced green energy conversion devices such as solid oxide fuel cells (SOFCs). Conventional SOFC electrolytes require a high operational temperature (over 700 °C) to maintain considerable bulk and grain boundary diffusion of the ions to enable sufficient ionic conductivity for efficient fuel cell operation. The present study explores a novel ion conduction expressway in an amorphous/crystalline heterostructure, La0·8Sr0·2Al0·8Zn0·2O3-d (LSAZ), which can boost the mobility of ions at a relatively low temperature (450-550 °C) for SOFCs. The LSAZ heterostructure includes an insulating perovskite core and a superionic-conducting amorphous surface layer. This electrolyte exhibits a superior conductivity of 0.319 S cm-1 at 550 °C, and it is employed in a SOFC which demonstrates a remarkable performance of 1296 mW cm-2 at 550 °C, which is 300 times higher than a SOFC with the LSAZ being densified at 1400 °C for 10 h. A superionic conducting amorphous surface layer enriched by high oxygen vacancy defects facilitates ionic conduction along the grain boundary and interfaces between the nanoparticles of LSAZ. Our finding provides an efficient way to design advanced highly conductive electrolytes for solid oxide fuel cells to be operated at reduced temperatures. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://repository.lboro.ac.uk/articles/dataset/Supplementary_information_files_for_Fast_ion-conduct... |