Direct Seawater Electrolysis Patents: Who Leads, Where the Gaps Are 2026
- A small, flat field. 19 patent families total, peaking at 6 filings in 2022 with no clear upward trend since — this is still an early, unconsolidated technology.
- No dominant assignee. Momentum data shows every tracked assignee at zero filings in the latest year, including recent entrants — a sign of a field still waiting for its next filing wave rather than one led by an incumbent.
- Claims cluster narrowly. Almost every family sits inside C25B electrolytic production, with only thin overlap into batteries, water treatment or nanotechnology — adjacent engineering problems remain largely unclaimed.
What the seawater electrolysis patent record actually covers
Direct seawater electrolysis skips the desalination step that conventional hydrogen electrolysis relies on, which means the patentable problem is almost entirely about surviving chloride — stopping chlorine evolution at the anode, resisting corrosion at the electrode, and keeping catalysts selective for oxygen evolution rather than chlorine oxidation. The corpus here is built around exactly that intersection: chloride-resistant catalyst, selective oxygen evolution, anti-corrosion electrode and seawater electrolyzer language layered onto the core electrolytic-production IPC classes.
At 19 total families, this is a narrow, still-forming field rather than a mature one. Filing activity has not shown sustained growth since the first records appeared, and no single assignee has repeated filings in the most recent year — both signs that the underlying chemistry problem is still open rather than settled by an incumbent's claim estate.
Filing trend and technology composition
Publication lags filing by roughly 18 months, so the 2025-2026 figures in any trend line are undercounts, not a real drop-off. Read the composition chart alongside the trend: it shows where claims concentrate today, not where the field is necessarily heading.
A flat filing curve since the 2022 peak
Filings rose from zero in 2017 to a peak of 6 in 2022, the midpoint of the tracked window. Activity has not sustained growth past that peak, which argues against treating this as a fast-scaling technology — it reads more as a series of discrete research pushes than a continuous filing ramp.
Concentrated in electrolytic production, thin everywhere else
All 19 families sit under C25B (electrolytic production of compounds), with secondary counts in B01J catalysis, C02F water treatment and H01M batteries/fuel cells. Single-digit counts in C01F, B82Y, F01D and F17D mark real but barely-claimed adjacencies — pipeline transport and turbine integration in particular look almost entirely open.
Shares are the percentage of the 19 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Direct Seawater Electrolysis Technology Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about direct seawater electrolysis technology landscape and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited filings in this corpus
Energy system using byproducts generated from seawater electrolyzer
This filing from KWATERCRAFT covers capturing and refining byproduct hydrogen from a seawater electrolyzer, feeding it to a fuel cell, and converting the alkali byproducts into high-purity magnesium oxide — turning the electrolyzer's chlorine and alkali waste streams into a second revenue path rather than treating them purely as corrosion hazards to manage.Filed 2022-06-30
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20230010138A1 | Universal One-Step Method to Make Fe-Based (Oxy)Hydroxides as Efficient OER Catalysts for Seawater Electrolys… | 29 |
| 2 | WO2021030755A1 | Non-noble metal-nitride based electrocatalysts for high-performance seawater splitting | 15 |
| 3 | US20220349066A1 | Non-Noble Metal-Nitride Based Electrocatalysts for High-Performance Seawater Splitting | 9 |
| 4 | US20170314144A1 | Seawater Electrolysis Hydrogen Recovery And Power Generation System | 9 |
| 5 | WO2023283005A1 | Universal one-step method to make fe-based (OXY)hydroxides as efficient OER catalysts for seawater electrolys… | 2 |
| 6 | JP2020006340A | Seawater electrolysis electrolyzer | 1 |
| 7 | WO2017187246A1 | 电解海水氢气回收与发电系统 | 1 |
Citation counts reward older filings simply for having more time to accumulate references — treat this as a measure of influence within the searched corpus, not a ranking of current technical merit.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Publication numbers are shown where the record carries one (7 of 7 rows); clicking a row searches Eureka by that number.
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Three patterns stand out once the families are broken down by class, geography and citation weight.
A field small enough to read in full
With only 19 families across the entire 2015-2026 window, this is not a crowded prior-art landscape. A freedom-to-operate review here is tractable in a way it would not be for a mainstream electrolysis or fuel-cell search.
US and PCT routes lead, India close behind
The United States and WIPO/PCT each account for 5 filings, with India at 4 — an unusually strong showing for India relative to Europe (2), Canada (1) and China (1). That spread suggests applicants are hedging across jurisdictions rather than concentrating on one home market.
Influence sits on a handful of catalyst filings
The most-cited record, on Fe-based (oxy)hydroxide OER catalysts for seawater electrolysis, draws 29 citations — more than double the next entry. Citation weight here tracks catalyst chemistry, not electrolyzer system design.
Co-filing is rare and mostly bilateral
Only 7 co-assignee pairs appear across the whole corpus, and the strongest pairing appears just twice. This is a field of largely independent filers rather than joint-venture or consortium-style patenting.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to direct seawater electrolysis technology landscape, with the prior art for and against each one.
Who is filing, and where the field is still open
No assignee in this corpus shows filings in the most recent tracked year, and two of the more active names show a full drop from prior activity. That combination — small numbers, no repeat filer with current momentum — points to a field between research waves rather than one being actively consolidated by an incumbent.
Momentum has stalled across the board
Every assignee tracked for recent-year momentum, including universities and corporates, shows zero filings in the latest year. Some show a full year-on-year drop from prior activity. This is consistent with a technology waiting on either a chemistry breakthrough or a commercial trigger before the next filing wave.
Public research institutes anchor the collaborative filings
The strongest co-assignee pairing links a petroleum-technology research institute with a national power utility, filed together twice. That pattern — applied research institute plus an energy operator — is the closest thing to an institutional cluster this dataset shows.
System integrators file around the catalyst layer, not into it
Filings like the byproduct-hydrogen energy system sit adjacent to the catalyst chemistry rather than competing with it directly, covering downstream capture, storage and conversion of electrolysis byproducts.
| Assignee | Recent year | YoY |
|---|---|---|
| University of Houston System | 0 | -100% |
| YU CHUN YI | 0 | — |
| RAJIV GANDHI INST OF PETROLEUM TECH | 0 | — |
| NTPC Limited | 0 | — |
| KWATERCRAFT CO LTD | 0 | — |
| University of Adelaide | 0 | -100% |
| Yu Chun-Te | 0 | — |
| Yu Chun-Yi | 0 | — |
Where to take this analysis
The dataset flags where claim density sits today; deciding where to file or challenge next needs a closer read of the specific claim language.
Run a freedom-to-operate check on chloride-resistant catalysts
With citation weight concentrated in a small number of OER catalyst filings, a targeted claim-scope review of those records is the highest-value first step before drafting new catalyst claims.
Explore in Patsnap EurekaTrack the under-claimed system branches
Turbine integration, pipeline transport of byproducts and nanostructured coatings show almost no direct coverage. Monitoring alerts on these IPC-adjacent classes can catch a new filing wave early.
Set up monitoring in Patsnap EurekaCommon questions on direct seawater electrolysis patents
This corpus tracks 19 patent families published between 2015 and mid-2026, matched against chloride-resistant catalyst, selective oxygen evolution, anti-corrosion electrode and seawater electrolyzer terminology within the core electrolytic-production IPC classes. That is a small field compared with mainstream water electrolysis or fuel-cell patenting, which makes a full prior-art read realistic rather than a sampling exercise. Filing peaked at 6 in 2022 and has not exceeded that since, though the most recent one to two years will read low simply because publication lags filing by around 18 months.
No single assignee dominates this corpus; the ranking is a long tail of research institutes, universities and a handful of corporates, each with a small number of filings. The strongest collaborative link is between a petroleum-technology research institute and a national power utility, who co-filed twice — the largest co-filing count in the dataset. Recent-year momentum data shows every tracked assignee, including the more active historical filers, at zero filings in the latest year, so there is currently no assignee actively scaling its position.
The overwhelming majority address one of two linked problems: stopping unwanted chlorine evolution at the anode in favour of selective oxygen evolution, or protecting electrodes and catalysts from chloride-driven corrosion. Nearly all 19 families sit under the C25B electrolytic-production classification, with secondary coverage in catalysis (B01J) and water treatment (C02F). Very little patent activity touches system-level integration such as turbines or pipeline transport of byproducts, which remain comparatively open.
Filing activity rose from zero in 2017 to a peak of 6 families in 2022, but has not shown sustained growth beyond that peak in the years since. Combined with the fact that every tracked assignee shows zero filings in the most recent year, the pattern looks more like a discrete research push than a continuously scaling field. Some caution is warranted on the very latest years, since publication lag means 2025-2026 filings are undercounted in any dataset pulled before mid-2026.
The clearest gaps sit just outside the core catalyst chemistry: turbine-integrated electrolyzer systems, pipeline transport of electrolysis byproducts, and nanostructured chloride-resistant coatings each show only single-digit or zero direct coverage in this corpus. These adjacencies are technically plausible extensions of the core chemistry but have not attracted concentrated filing yet, which makes them worth watching for a first-mover claim rather than filing into the crowded catalyst-selectivity space where the highest-cited prior art already sits.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.