PEM Water Electrolysis Patent Landscape 2026
PEM Water Electrolysis Patent Landscape in 2026
PEM water electrolysis patent activity is in a Growth stage, with filings expanding strongly over the multi-year window and the field still rising rather than having eased from a peak. UOP LLC holds a commanding lead with 161 patent families, while Siemens Energy and 1S1 Energy trail at roughly half that volume, pointing to a moderately concentrated but actively contested space.
UOP LLC leads a moderately concentrated field with clear tier gaps
UOP LLC is the clear KG at 73 patent families and 1S1 Energy Inc at 64 patent families.
The top five filers — UOP LLC, Siemens Energy, 1S1 Energy, Air Products & Chemicals, and Hysata — together account for 33% of the combined output of the hundred largest filers, indicating a moderately concentrated structure with meaningful room for challengers below the top tier.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | UOP LLC | 161 | |
| 2 | SIEMENS ENERGY GLOBAL GMBH & CO KG | 73 | |
| 3 | 1S1 Energy Inc | 64 | |
| 4 | AIR PROD & CHEM INC | 42 | |
| 5 | Hysata Pty Ltd | 33 | |
| 6 | 3M Innovative Properties Co | 29 | |
| 7 | Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 26 | |
| 8 | Robert Bosch GmbH | 25 | |
| 9 | IDE Water Technologies Ltd | 24 | |
| 10 | UMICORE AG & CO KG | 23 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Shaheen Innovations Holding Ltd | 21 | |
| 12 | C&R ENTERPRISES CO | 21 | |
| 13 | AeroVironment Inc | 19 | |
| 14 | Toray Industries Inc | 17 | |
| 15 | Yokogawa Electric Corporation | 15 | |
| 16 | Ohmium International Inc | 15 | |
| 17 | Fraunhofer Society | 15 | |
| 18 | HERAEUS DEUTSCHLAND GMBH & CO KG | 15 | |
| 19 | Brilliant Light Power Inc | 15 | |
| 20 | Atomic Energy of Canada Limited | 15 |
UOP LLC’s position, anchored heavily in fuel cell and electrolytic compound production subclasses, reflects a mature internal portfolio that newer entrants such as Hysata and Robert Bosch are only beginning to challenge through focused cell-architecture and system-level filings.
Patent records from the most recent 18–24 months are under-counted due to publication lag; apparent softness in 2025–2026 figures should not be interpreted as a real decline in activity. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filings have grown sharply since 2020 and the technology mix is anchored in core electrolytic chemistry
Two charts together reveal both the pace of investment and where technical effort is concentrated: the annual trend shows a sustained surge from 2020 onward, while the IPC composition confirms that core electrolytic production and fuel-cell subclasses dominate but a long tail of adjacent branches is present.
Annual filing trend
Filings rose from 44 in 2017 to a recorded high of 328 in 2023, representing 189% growth over the recent window. The 2024 and 2025 counts should be treated as under-stated due to publication lag; the apparent plateau does not signal a genuine slowdown.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) is overwhelmingly dominant, reflecting the core electrochemical focus of the field. H01M (batteries, cells and fuel cells) is the second-largest branch, capturing membrane and electrode cross-filing. A long tail of branches — from B01J catalysis through C08J polymer processing — signals growing interest in enabling materials and supporting processes.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Electrocatalyst for polymer electrolyte membrane (…
Proposed are an electrocatalyst for polymer electrolyte membrane (PEM) water electrolysis, the electrocatalyst including an iridium-based catalyst, wherein the iridium-based catalyst is a core-shell particle, the core contains iridium metal, and the shell contains an iridium tin composite oxide, a method of preparing the same, a PEM water electrolysis… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Method and apparatus for integrated water deioniza… | 143 |
| 2 | Apparatus for integrated water deionization, elect… | 130 |
| 3 | Bifunctional catalytic electrode | 115 |
| 4 | Water sources for automotive electrolyzers | 79 |
| 5 | Method and apparatus for integrated water deioniza… | 70 |
| 6 | Unitized regenerative fuel cell with bifunctional … | 68 |
| 7 | Energy storage system | 64 |
| 8 | 水电解用贵金属氧化物催化剂 | 62 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the patent structure means for R&D strategy
The combination of a Growth life-cycle stage, a moderate concentration ratio, active cross-sector collaboration, and broad geographic filing defines both the opportunity and the competitive risk for new entrants and incumbents alike.
Growth stage — annual volume still rising on a multi-year basis
The field is classified as Growth, with annual filings expanding strongly since 2020 and no evidence of easing from a peak. The 189% growth recorded over the recent window confirms that PEM electrolysis remains an actively contested frontier rather than a maturing or declining area. R&D investment decisions should account for an accelerating prior-art landscape that is being built in real time.
Life-cycle: GrowthModerate concentration with a pronounced leader gap
The top five filers hold 33% of the combined output of the hundred largest filers, a moderate concentration level that leaves meaningful space for mid-tier challengers. However, UOP LLC’s lead of 161 patent families — more than twice Siemens Energy’s 73 — creates a practical barrier in the core electrochemical and fuel-cell subclasses. New entrants may find more accessible entry points in adjacent enabling-material or system-integration branches where the incumbent density is lower.
Concentration: moderateEarly-stage cross-institutional co-filing, led by Dalian Institute with State Grid entities
The most active co-filing pairs identified in the evidence are Siemens Energy Global with Siemens AG, the Dalian Institute of Chemical Physics (Chinese Academy of Sciences) with State Grid Liaoning Electric Power and with State Grid Corporation of China, and BASF with the Max Planck Society. These pairings suggest that the dominant collaboration model pairs industrial hydrogen system developers with grid operators or fundamental-research institutes, rather than horizontal industry alliances.
Collaboration: emergingUnited States and China are co-leading jurisdictions; Europe and PCT filings are substantial
The United States leads on patent records with 422, closely followed by China at 408. Europe (EPO) at 261 and WIPO (PCT) at 217 indicate strong multi-jurisdictional protection strategies among the leading filers. Australia (142) appears notably high, reflecting the domestic base of Hysata and Aquahydrex. Filings in South Korea (26) and Japan (19) are relatively sparse given those nations’ industrial hydrogen programs, suggesting either strategic under-filing or a gap worth monitoring.
Geography: US–China parityGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| Siemens Energy Global GmbH & Co. KG | Siemens AG | 2 |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | State Grid Liaoning Electric Power Co Ltd | 2 |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | State Grid Corporation of China | 2 |
| BASF SE | Max Planck Society for the Advancement of Science | 1 |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | China Three Gorges Corporation | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
UOP LLC and Siemens Energy lead by volume, with BASF and Bosch accelerating as new entrants
The two dominant filers differ meaningfully in technical emphasis: UOP LLC straddles fuel-cell and electrolytic production subclasses, while Siemens Energy concentrates more tightly on core electrolytic and electrolyzer cell architecture.
UOP LLC
UOP LLC holds 161 patent families, the largest portfolio in the corpus. Its technology emphasis spans H01M 8 (fuel cells) and C25B 1 and C25B 13 (electrolytic production of compounds), indicating a dual focus on PEM cell architecture and hydrogen production chemistry. Recent-period momentum is strong at 3.1× vs. the prior three-year window (110 recent families), reflecting an accelerating rather than consolidating strategy.
families: 161Siemens Energy Global GmbH & Co. KG
Siemens Energy Global holds 73 patent families and is classified as a new entrant in momentum terms, having built its position in the recent filing window. Its technical focus is concentrated in C25B 1 (electrolytic compounds), C25B 9 (electrolyzer cell structures), and C25B 11 (electrodes and catalysts), marking a more system- and cell-architecture-oriented portfolio compared to UOP LLC’s dual hydrogen-production and fuel-cell footprint.
families: 73| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| UOP LLC | 110 | ▲ 3.1× vs prior 3-yr |
| BASF SE | 45 | ▲ new entrant |
| Siemens Energy Global GmbH & Co. KG | 56 | ▲ new entrant |
| 1S1 Energy Inc | 25 | ▼ -34% |
| Air Products and Chemicals Inc | 23 | ▲ +21% |
| Hysata Pty Ltd | 7 | ▼ -70% |
| Dalian Institute of Chemical Physics, Chinese Academy of Sciences | 13 | ▲ +30% |
| Robert Bosch GmbH | 16 | ▲ new entrant |
Under-served adjacent branches in catalysis, separation, and polymer processing
Several IPC branches adjacent to the dominant C25B core show relatively low filing share despite clear technical relevance to PEM electrolysis performance; they represent areas of observed sparsity that may warrant closer examination before concluding they are genuine white spaces.
B01J · Chemical/physical processes & catalysis
With 178 patent records and a 5% share of the branch distribution, B01J covers catalyst design and heterogeneous reaction engineering — directly relevant to PEM oxygen evolution and hydrogen evolution reaction catalyst development. The relatively low share compared to the dominant C25B branch suggests that fundamental catalyst innovation is under-patented relative to cell and system integration, which could represent an entry point for materials-focused R&D teams with expertise in iridium or platinum-group metal alternatives.
Search this in Eureka →C08J · Polymer processing & solutions
C08J covers membrane fabrication and polymer solution processing, with 115 patent records and a 3% share — notable given that the proton-exchange membrane is the defining component of PEM electrolyzers. The sparse filing relative to C25B suggests that membrane processing know-how is either held as trade secret, concentrated in a small number of filers such as 1S1 Energy Inc (whose top focus includes C08J 5), or genuinely under-explored. Organizations with fluoropolymer or ionomer processing capabilities may find this branch accessible.
Search this in Eureka →How leading filers differ across core PEM technology routes
Strength of each leader across the main technology routes.
| Player | C25B 1 · Electrolytic production of compounds | C25B 9 · Electrolytic production of compounds | C25B 11 · Electrolytic production of compounds | C25B 15 · Electrolytic production of compounds | H01M 8 · Batteries, cells & fuel cells |
|---|---|---|---|---|---|
| UOP LLC | Strong · 77 | Strong · 48 | Moderate · 37 | Absent | Strong · 86 |
| Siemens Energy Global GmbH & Co. KG | Strong · 50 | Strong · 50 | Strong · 28 | Moderate · 23 | Moderate · 17 |
| BASF SE | Strong · 60 | Absent | Strong · 34 | Absent | Moderate · 20 |
| 1S1 Energy Inc | Absent | Absent | Absent | Absent | Strong · 62 |
| 3M Innovative Properties Co | Strong · 19 | Strong · 21 | Strong · 19 | Absent | Absent |
| Shaheen Innovations Holding Ltd | Strong · 16 | Strong · 21 | Absent | Strong · 21 | Absent |
| Air Products and Chemicals Inc | Strong · 39 | Absent | Absent | Moderate · 16 | Absent |
Frequently asked questions
The corpus contains 1,568 patent families in scope. This is the universe on which applicant rankings, trend analysis, and technology composition are based.
UOP LLC leads with 161 patent families, more than twice the volume of the second-ranked Siemens Energy Global GmbH & Co. KG at 73 patent families. UOP LLC’s recent momentum is 3.1× vs. its prior three-year window, indicating an accelerating rather than plateauing position.
The United States leads with 422 patent records, closely followed by China at 408. Europe (EPO) at 261 and WIPO (PCT) at 217 indicate widespread multi-jurisdictional filing strategies. Australia at 142 is notably active, reflecting the domestic base of companies such as Hysata.
The field is classified as Growth. Annual filings rose from 44 in 2017 to a recorded high of 328 in 2023, with 189% growth over the recent window. The 2024–2026 figures are under-counted due to publication lag and should not be read as a genuine slowdown.
C25B (electrolytic production of compounds) is overwhelmingly dominant. H01M (batteries, cells and fuel cells) is the second-largest branch. Adjacent branches including B01J (catalysis), B01D (separation), C01B (inorganic compounds), C08J (polymer processing), and C02F (water treatment) each carry lower filing shares and represent areas of relative sparsity compared to the core.
BASF and Siemens Energy Global are both classified as new entrants in the recent filing window, having built their positions quickly. Robert Bosch GmbH is also a new entrant in momentum terms. UOP LLC shows 3.1× growth vs. the prior three-year period. Air Products & Chemicals shows more moderate growth at +21%, while 1S1 Energy and Hysata have seen recent-period declines of -34% and -70% respectively.
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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.
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