Challenges and strategies in catalysts design towards efficient and durable alkaline seawater electrolysis for green hydrogen production

Abstract

Seawater electrolysis offers a sustainable solution for hydrogen production by utilizing ocean water as an electrolyte. However, the chlorine evolution reaction (ClER) and the accumulation of magnesium and calcium precipitates pose significant challenges to efficiency and durability. ClER competes with the oxygen evolution reaction, reducing hydrogen output and accelerating electrode degradation, while precipitate formation on the cathode blocks catalytic sites and impairs long-term performance. Anion exchange membrane water electrolyzers tackle these challenges by leveraging alkaline media to suppress ClER and enhance catalyst stability. Recent advances in selective catalysts, protective coatings, and alternative oxidation reactions further improve reaction selectivity and energy efficiency. Additionally, strategies such as surface engineering and pH modulation mitigate precipitate formation, ensuring stable operation. Scaling these innovations into anion exchange membrane water electrolyzer systems demonstrates their potential for industrial-level hydrogen production. By overcoming fundamental challenges and practical barriers, seawater electrolysis advances toward commercial deployment and a sustainable energy future.

Keywords

Green hydrogen / seawater electrolysis / oxygen evolution reaction / non-noble metal catalysts / electrocatalysis / water splitting

References

[1] Bradshaw A.Electrical conductivity of seawater.IEEE J Ocean Eng1980;5:50-62

[2] Yu Z.Recent advances in hybrid seawater electrolysis for hydrogen production.Adv Mater2024;36:e2308647

[3] Liu G,Yang T.Recent advances in electrocatalysts for seawater splitting.Nano Mater Sci2023;5:101-16

[4] Fei H,Liu T.Direct seawater electrolysis: from catalyst design to device applications.Adv Mater2024;36:e2309211

[5] Hu H,Attfield JP.Metal nitrides for seawater electrolysis.Chem Soc Rev2024;53:163-203

[6] Tong W,Dionigi F.Electrolysis of low-grade and saline surface water.Nat Energy2020;5:367-77

[7] Xiao X,Sun W.Electrocatalytic water splitting: from harsh and mild conditions to natural seawater.Small2022;18:e2105830

[8] Liu Y,Fornasiero P,Strasser P.Long-term durability of seawater electrolysis for hydrogen: from catalysts to systems.Angew Chem Int Ed2024;136:e202412087

[9] Karlsson RK.Selectivity between oxygen and chlorine evolution in the chlor-alkali and chlorate processes.Chem Rev2016;116:2982-3028

[10] Bahuguna G.Routes to avoiding chlorine evolution in seawater electrolysis: recent perspective and future directions.ACS Mater Lett2024;6:3202-17

[11] Bahuguna G.Why today’s “water” in water splitting is not natural water? Critical up-to-date perspective and future challenges for direct seawater splitting.Nano Energy2023;117:108884

[12] Haq TU.Strategies of anode design for seawater electrolysis: recent development and future perspective.Small Sci2022;2:2200030

[13] Liang J,He X.Electrocatalytic seawater splitting: nice designs, advanced strategies, challenges and perspectives.Mater Today2023;69:193-235

[14] Gouda VK,Riad WT.Microbiologically induced corrosion of UNS N04400 in seawater.Corrosion1993;49:63-73

[15] Oh BS,Jung YJ,Kang J.Evaluation of a seawater electrolysis process considering formation of free chlorine and perchlorate.Desalination Water Treat2010;18:245-50

[16] Kang X,Zhang Z.A corrosion-resistant RuMoNi catalyst for efficient and long-lasting seawater oxidation and anion exchange membrane electrolyzer.Nat Commun2023;14:3607 PMCID:PMC10276855

[17] Park YS,Jang MJ.Ternary layered double hydroxide oxygen evolution reaction electrocatalyst for anion exchange membrane alkaline seawater electrolysis.J Energy Chem2022;75:127-34

[18] Yang P,Zang X.Microwave quasi-solid state to construct strong metal-support interactions with interfacial electron-enriched Ru for anion exchange membrane electrolysis.Adv Energy Mater2024;14:2303384

[19] Hu H,Liu L.Efficient and durable seawater electrolysis with a V₂O₃-protected catalyst.Sci Adv2024;10:eadn7012 PMCID:PMC11100561

[20] Chang J,Yang Z.Dual-doping and synergism toward high-performance seawater electrolysis.Adv Mater2021;33:e2101425

[21] Xia Y,Zhu J.Manipulating electronic structure of nickel phosphide via asymmetric coordination interaction for anion-exchange membrane based seawater electrolysis.Appl Catal B Environ Energy2024;351:123995

[22] Song L,Mao J.Boosting hydrogen adsorption via manipulating the d-band center of ferroferric oxide for anion exchange membrane-based seawater electrolysis.ACS Catal2024;14:6981-91

[23] Wang H,Huang B,Guan L.Surface amorphization and functionalization of a NiFeOOH electrocatalyst for a robust seawater electrolyzer.EES Catal2024;2:1092-9

[24] Li Q,Li H.Strong d-p orbital hybridization of Os-P via ultrafast microwave plasma assistance for anion exchange membrane electrolysis.Adv Funct Mater2024;34:2408517

[25] Cui T,Liu K.Manipulating the electron redistribution of Fe₃O₄ for anion exchange membrane based alkaline seawater electrolysis.Appl Catal B Environ Energy2024;357:124269

[26] Jun SE,Cho B.Exsolved Ru-mediated stabilization of MoO₂-Ni₄Mo electrocatalysts for anion exchange membrane water electrolysis and unbiased solar-driven saline water splitting.Appl Catal B Environ Energy2024;358:124364

[27] Lee SA,Lee J.High-entropy nanomaterials for advanced electrocatalysis.Small Sci2023;3:2200109

[28] Choi D.Efficient and selective oxygen evolution reaction in seawater electrolysis with electrochemically synthesized amorphous-like NiFeS.Electron Mater Lett2024;20:173-82

[29] Cho YB,Hua SH.Direct detection of water-dissolved ammonia using paper-based analytical devices.J Sensor Sci Technol2023;32:67-74

[30] Kim J,Kim S.Catalyze materials science with machine learning.ACS Mater Lett2021;3:1151-71

[31] Vos JG,Jeremiasse AW.MnO_x/IrO_x as selective oxygen evolution electrocatalyst in acidic chloride solution.J Am Chem Soc2018;140:10270-81 PMCID:PMC6099550

[32] Hu H,Zhang Y.An ultra-low Pt metal nitride electrocatalyst for sustainable seawater hydrogen production.Energy Environ Sci2023;16:4584-92

[33] Veroneau SS.Continuous electrochemical water splitting from natural water sources via forward osmosis.Proc Natl Acad Sci USA2021;118:e2024855118 PMCID:PMC7936378

[34] Desai D,Sahu S.Electrochemical desalination of seawater and hypersaline brines with coupled electricity storage.ACS Energy Lett2018;3:375-9

[35] Loutatidou S,Marpu PR.Capital cost estimation of RO plants: GCC countries versus southern Europe.Desalination2014;347:103-11

[36] Logan BE,Rossi R.Enabling the use of seawater for hydrogen gas production in water electrolyzers.Joule2021;5:760-2

[37] Lee JK,Lim J,Jang HW.Best practices in membrane electrode assembly for water electrolysis.ACS Mater Lett2024;6:2757-86

[38] Abbasi R,Lin S.A roadmap to low-cost hydrogen with hydroxide exchange membrane electrolyzers.Adv Mater2019;31:e1805876

[39] Li J,Li Z.Recent advances in electrocatalysts for seawater splitting in hydrogen evolution reaction.Int J Hydrogen Energy2022;47:29685-97

[40] Lee SA,Kwon KC,Jang HW.Anion exchange membrane water electrolysis for sustainable large-scale hydrogen production.Carbon Neutral2022;1:26-48

[41] Vincent I.Low cost hydrogen production by anion exchange membrane electrolysis: a review.Renew Sustain Energy Rev2018;81:1690-704

[42] Shao L,Shi L.In situ generation of molybdate-modulated nickel-iron oxide electrodes with high corrosion resistance for efficient seawater electrolysis.Adv Energy Mater2024;14:2303261

[43] Xu W,Liu P.Ag nanoparticle-induced surface chloride immobilization strategy enables stable seawater electrolysis.Adv Mater2024;36:e2306062

[44] Zhang S,Chen H.Progress in anode stability improvement for seawater electrolysis to produce hydrogen.Adv Mater2024;36:e2311322

[45] Huang C,Yu L.Functional bimetal Co-modification for boosting large-current-density seawater electrolysis by inhibiting adsorption of chloride ions.Adv Energy Mater2023;13:2301475

[46] Gong Z,Yan M,Ye G.Highly durable and efficient seawater electrolysis enabled by defective graphene-confined nanoreactor.ACS Nano2023;17:18372-81

[47] Fan R,Li Z.Ultrastable electrocatalytic seawater splitting at ampere-level current density.Nat Sustain2024;7:158-67

[48] Liu J,Shi H.Breaking the scaling relations of oxygen evolution reaction on amorphous NiFeP nanostructures with enhanced activity for overall seawater splitting.Appl Catal B Environ2022;302:120862

[49] Liu H,Jin H.High-performance alkaline seawater electrolysis with anomalous chloride promoted oxygen evolution reaction.Angew Chem Int Ed2023;62:e202311674

[50] Zhao Y,Huang C.Oxygen evolution/reduction reaction catalysts: from in situ monitoring and reaction mechanisms to rational design.Chem Rev2023;123:6257-358

[51] Dionigi F,Pawolek Z,Strasser P.Design criteria, operating conditions, and nickel-iron hydroxide catalyst materials for selective seawater electrolysis.ChemSusChem2016;9:962-72

[52] Guo J,Hu Z.Direct seawater electrolysis by adjusting the local reaction environment of a catalyst.Nat Energy2023;8:264-72

[53] Dresp S,Loos S.Direct electrolytic splitting of seawater: activity, selectivity, degradation, and recovery studied from the molecular catalyst structure to the electrolyzer cell level.Adv Energy Mater2018;8:1800338

[54] Jung H,Lee Y.Computational discovery of optimal dopants for nickel iron oxyhydroxide to enhance OER activity and saline water compatibility.ACS Energy Lett2024;9:2162-72

[55] Zhang S,Li S.Concerning the stability of seawater electrolysis: a corrosion mechanism study of halide on Ni-based anode.Nat Commun2023;14:4822 PMCID:PMC10415325

[56] Dresp S,Klingenhof M.Direct electrolytic splitting of seawater: opportunities and challenges.ACS Energy Lett2019;4:933-42

[57] Han J,Lee H.Direct seawater electrolysis via synergistic acidification by inorganic precipitation and proton flux from bipolar membrane.Chem Eng J2022;429:132383

[58] Li T,Getaye Sendeku M.Phosphate-decorated Ni₃Fe-LDHs@CoPx nanoarray for near-neutral seawater splitting.Chem Eng J2023;460:141413

[59] Li J,Wang K.Multiscale engineering of nonprecious metal electrocatalyst for realizing ultrastable seawater splitting in weakly alkaline solution.Adv Sci2022;9:e2202387 PMCID:PMC9443442

[60] Cai Z,Li Z.Stabilizing NiFe sites by high-dispersity of nanosized and anionic Cr species toward durable seawater oxidation.Nat Commun2024;15:6624 PMCID:PMC11300586

[61] Li P,Huang Y,Yang Y.Multiscale structural engineering of a multilayered nanoarray electrode realizing boosted and sustained oxygen evolution catalysis in seawater electrolysis.ACS Catal2023;13:15360-74

[62] Khan MA,Roy S.Seawater electrolysis for hydrogen production: a solution looking for a problem?.Energy Environ Sci2021;14:4831-9

[63] Karoui H,Jeannin M.Electrochemical scaling of stainless steel in artificial seawater: role of experimental conditions on CaCO₃ and Mg(OH)₂ formation.Desalination2013;311:234-40

[64] Kang W,Zhao Y.Scaling-free cathodes: enabling electrochemical extraction of high-purity nano-CaCO₃ and -Mg(OH)₂ in seawater.Environ Sci Technol2024;58:14034-41

[65] Yi L,Wen Y.Solidophobic surface for electrochemical extraction of high-valued Mg(OH)₂ coupled with H₂ production from seawater.Nano Lett2024;24:5920-8

[66] Lee S,Lee D,Park J.Synthesis of seawater-derived superhydrophobic calcium carbonate via CO₂ mineralization by utilizing L-Arginine/L-Lysine oleate-based self-assembly structures.Chem Eng J2024;490:151785

[67] Dresp S,Klingenhof M,Hauke P.Efficient direct seawater electrolysers using selective alkaline NiFe-LDH as OER catalyst in asymmetric electrolyte feeds.Energy Environ Sci2020;13:1725-9

[68] Zhou Z,Wei L,Jian X.Electrocatalytic hydrogen evolution under neutral pH conditions: current understandings, recent advances, and future prospects.Energy Environ Sci2020;13:3185-206

[69] Rodriguez-blanco J,Bots P,Benning L.The role of pH and Mg on the stability and crystallization of amorphous calcium carbonate.J Alloys Compd2012;536:S477-9

[70] Yousefi S,Tajally M.Optical properties of MgO and Mg(OH)₂ nanostructures synthesized by a chemical precipitation method using impure brine.J Alloys Compd2017;711:521-9

[71] Chen H,Li W.Stable seawater electrolysis over 10 000 H via chemical fixation of sulfate on NiFeBa-LDH.Adv Mater2024;36:e2411302

[72] Liao L,Zhang Y.Complementary multisite turnover catalysis toward superefficient bifunctional seawater splitting at ampere-level current density.Adv Mater2024;36:e2405852

[73] Liu X,Mao H.Principles of designing electrocatalyst to boost reactivity for seawater splitting.Adv Energy Mater2023;13:2301438

[74] Tlili MM,Gabrielli C,Tribollet B.Influence of the interfacial pH on electrochemical CaCO₃ precipitation.J Electrochem Soc2003;150:C765

[75] Zheng W,Wong KY.Improving the performance stability of direct seawater electrolysis: from catalyst design to electrode engineering.Nanoscale2021;13:15177-87

[76] Liu J,Shi H.Rationally designing efficient electrocatalysts for direct seawater splitting: challenges, achievements, and promises.Angew Chem Int Ed2022;61:e202210753

[77] Xie H,Liu T.A membrane-based seawater electrolyser for hydrogen generation.Nature2022;612:673-8

[78] Adisasmito S,Sutrisna PD,Siagian UWR.Bipolar membrane seawater splitting for hydrogen production: a review.ACS Omega2024;9:14704-27 PMCID:PMC10993265

[79] Zheng Y.Direct seawater splitting to hydrogen by a membrane electrolyzer.Joule2023;7:20-2

[80] Jin H,Liu H.Emerging materials and technologies for electrocatalytic seawater splitting.Sci Adv2023;9:eadi7755 PMCID:PMC10584342

[81] Liang J,He X.Electroreduction of alkaline/natural seawater: self-cleaning Pt/carbon cathode and on-site co-synthesis of H₂ and Mg hydroxide nanoflakes.Chem2024;10:3067-87

[82] Zhao L,Lv Z.Anti-precipitation molecular metal chalcogenide complexes modification for efficient direct alkaline seawater splitting at the large current density.Appl Catal B Environ2023;338:122996

[83] Yang C,Zheng Y.Electron-donating Cu atoms induced high proton supply and anti-poisoning ruthenium clusters for superior direct seawater hydrogen production.Adv Funct Mater2024;34:2404061

[84] Liang J,Li Z.Efficient bubble/precipitate traffic enables stable seawater reduction electrocatalysis at industrial-level current densities.Nat Commun2024;15:2950 PMCID:PMC10997793

[85] Jwa E,Chon K.Bioelectrochemical precipitation system for removal of scale-forming ions from seawater using two different buffers.Desalination2017;418:35-42

[86] Ren Y,Zhang Y.A Dual-cation exchange membrane electrolyzer for continuous H₂ production from seawater.Adv Sci2024;11:e2401702 PMCID:PMC11220719

[87] Shi H,Liu J.A sodium-ion-conducted asymmetric electrolyzer to lower the operation voltage for direct seawater electrolysis.Nat Commun2023;14:3934 PMCID:PMC10319863

[88] Li T,Cao Y.Energy-saving hydrogen production by seawater electrolysis coupling tip-enhanced electric field promoted electrocatalytic sulfion oxidation.Nat Commun2024;15:6173 PMCID:PMC11263359

[89] Sun F,Wang Z.Energy-saving hydrogen production by chlorine-free hybrid seawater splitting coupling hydrazine degradation.Nat Commun2021;12:4182 PMCID:PMC8263752