COMPANY PROFILE / HYDROGEN ENERGY
Tanaka Kikinzoku (Tanaka Precious Metals)
A precious metals manufacturer that supplies materials across hydrogen, from fuel cell and electrolysis catalysts to plated electrodes and hydrogen-permeable membranes
Tanaka Kikinzoku, known in English as Tanaka Precious Metals, was founded in 1885 and is a comprehensive precious metals manufacturer. Its businesses include industrial precious metal products (bonding wire, catalysts, pastes and more), the recovery and refining of precious metals, and bullion and jewelry. Its hydrogen activity sits in Tanaka Kikinzoku Kogyo K.K., which runs the industrial precious metals business. It has developed electrode catalysts for polymer electrolyte fuel cells (PEFCs) since 1985 and, in its own words, holds a leading place in world supply. More recently it has widened its range to catalysts for PEM water electrolysis, precious-metal-plated electrodes for electrolysis, catalysts for reforming and ammonia cracking, and palladium-based hydrogen-permeable membranes. In July 2026 it also began operating a 500 kW pure-hydrogen fuel cell power plant near its Shonan plant, making it both a supplier and a user of hydrogen. The company is unlisted, and its hydrogen-only sales, profit and headcount are not disclosed. Drawing on its statutory financial statements, official press releases, official product pages, and releases from NEDO and Kyoto University, this article sets out what could be confirmed and what could not, and explains from a materials engineer's view what matters in catalysts, electrodes and membranes.
- At a glance: Tanaka and its place in hydrogen energy
- Logo and naming
- Where the company sits in hydrogen energy
- Company scale
- Resources committed to hydrogen
- Track record
- Plans
- What the company is aiming for in hydrogen
- Partnership map for hydrogen
- Technologies, products and services
- Risks
- Glossary
- References
- Claim-to-source audit
1. At a glance: Tanaka and its place in hydrogen energy
(the hydrogen business entity)Also called Tanaka Precious Metals. Founded 1885, incorporated 1918
Chuo-ku, TokyoFrom the official company profile. Its fuel cell catalyst plant is at the Shonan plant (Hiratsuka, Kanagawa)
(within the scope checked)No official source showing a stock listing or securities report was found; financial statements are published as statutory statements
(catalysts, electrodes, membranes)PEFC and PEM electrolysis catalysts, plated electrodes, Pd hydrogen-permeable membranes, reforming and ammonia-cracking catalysts
(platinum, platinum alloys)Developed since 1985. Iridium oxide catalysts for water electrolysis are a growing second pillar
"Tanaka Kikinzoku" is not a single company but a family of companies. From official sources, the structure is this: under the parent Field In & Company Co., Ltd. (renamed on 1 January 2025 from TANAKA Holdings Co., Ltd.) sits Tanaka Kikinzoku Group Co., Ltd., which manages the group, and its wholly owned subsidiary Tanaka Kikinzoku Kogyo K.K. runs the industrial precious metals business, including the hydrogen-related products Sourced. The "hydrogen business" in this article belongs to Tanaka Kikinzoku Kogyo, but the consolidated financial statements are those of the parent, Field In & Company. Sales, profit and headcount for hydrogen alone are not published. What can be confirmed is the product range, announced capital projects, joint research and awards Not yet confirmed.
2. Logo and naming
The logo is the English version published in the header of TANAKA's official corporate website, reproduced as supplied by the company.
Naming: several legal entities are commonly called "Tanaka Kikinzoku." This article treats Tanaka Kikinzoku Kogyo K.K. as the hydrogen business entity. The group's management company is Tanaka Kikinzoku Group Co., Ltd. (established 2024), and its parent is Field In & Company Co., Ltd. (the English forms of the two group company names are our transliterations of their Japanese names). "TANAKA Holdings Co., Ltd." is the former name of that parent: on 1 January 2025 it split off its management functions to Tanaka Kikinzoku Group by a corporate split and then changed its name. Press releases from before 2025 therefore name TANAKA Holdings as the issuer.
Official site: TANAKA Corporate Website (English)3. Where the company sits in hydrogen energy
Tanaka's main type is materials & components. The technologies it serves are polymer electrolyte fuel cells (PEFCs), PEM water electrolysis, equipment that makes hydrogen by reforming city gas and similar fuels, equipment that makes hydrogen from ammonia, and hydrogen purification with palladium membranes. The breadth of materials and uses is its distinguishing feature. It has also become a user of hydrogen, with fuel cell power generation at its own plant, but that is for its own use, not a business selling equipment. The table sorts materials and uses by what company sources let us confirm.
| Material / use | Where it sits at Tanaka | Primary sources found | Status |
|---|---|---|---|
| Electrode catalysts for PEFCs (Pt/C, PtCo/C, PtRu/C) | The core of its hydrogen business. Developed since 1985. The company describes "world-leading supply results" (METI named it a Global Niche Top company in 2020) | Product page; press releases | Sourced (company description) |
| Electrode catalysts for PEM water electrolysis (iridium oxide, Pt-based) | A second pillar that is growing. The company says it developed and mass-produced a catalyst with two functions, oxygen evolution and hydrogen recombination (Catalyst Manufacturers' Association technology award, 2025). Sales are not disclosed | Product page; press releases | Sourced (company description) |
| Precious-metal-plated electrodes for PEM electrolysis (GDL, PTL) | Titanium substrates electroplated with Pt or PtIr, offered as current collectors, gas diffusion layers and porous transport layers | Product page | Sourced (company description) |
| Reforming, shift and PROX catalysts; ammonia-cracking catalysts | Catalysts (Ru, Rh, Pt) for equipment that makes hydrogen from city gas and from ammonia. The wider base of its hydrogen business | Product pages | Sourced (company description) |
| Palladium hydrogen-permeable membranes | Metal membranes for hydrogen purification. A membrane for about 300 °C (PdCu39, 2025) and one for about 100 °C (HPM-L111, 2026) have been developed; at the sample-supply stage | Press releases; product page | Sourced (company description) |
| Recovery, refining and recycling of precious metals | Recovers precious metals from used catalysts and similar material and turns them back into products. Also relevant to hydrogen-related catalysts | Official site; product pages | Sourced |
| Hydrogen use (own pure-hydrogen fuel cell power plant) | A 500 kW plant at the Shonan fuel cell power station began operating on 8 July 2026. The company says it is now both a supplier and a user | Press releases (2024, 2026) | Sourced |
| Electrolyzers, fuel cell systems, PEM membranes themselves | Not confirmed in company sources. Only a headline was found saying a CCM for evaluating electrolysis electrode catalysts was shown for the first time at an exhibition in 2018 | - | Not yet confirmed |
4. Company scale
Tanaka Kikinzoku is unlisted, and no securities report could be found. The official site publishes, as financial information, statutory financial statements (PDF) Sourced. The table below gives the scale of the whole group briefly and states how far disclosure goes for hydrogen. The financial year is the calendar year (January to December).
| Item | Detail |
|---|---|
| Tanaka Kikinzoku Kogyo K.K. (the hydrogen business entity) | Capital ¥500 million; sales ¥419,177,145,000 (FY2025); 2,862 employees (31 December 2025); head office at 2-6-6 Nihonbashi-Kayabacho, Chuo-ku, Tokyo; president and CEO Koichiro Tanaka. Business: manufacture, sale and import/export of precious metal bullion and industrial precious metal products, and recovery and refining of precious metals |
| Tanaka Kikinzoku Group Co., Ltd. | The group management company, owning Tanaka Kikinzoku Kogyo and others as wholly owned subsidiaries. Established 2024; the group moved to a structure centered on it in 2025 (history page). Statutory statements for its 2nd term (FY2025) are published. Its parent is Field In & Company (100% held directly) |
| Field In & Company Co., Ltd. | Formerly TANAKA Holdings. 39 consolidated subsidiaries and 8 equity-method affiliates (year to December 2025), including Tanaka Kikinzoku Kogyo, Tanaka Denshi Kogyo, EEJA and Metalor Technologies International SA |
| Hydrogen-only figures | Sales, profit, headcount, R&D spend and cumulative capex are all not disclosed. Only individually announced capital projects (about ¥1 billion in 2013, about ¥4 billion in 2018) could be confirmed |
| Consolidated (Field In & Company) | Year to December 2024 (160th term) | Year to December 2025 (161st term) |
|---|---|---|
| Net sales | ¥846,921 million | ¥1,097,813 million |
| Operating profit | ¥30,312 million | ¥44,517 million |
| Ordinary profit | ¥37,906 million | ¥51,853 million |
| Profit attributable to owners of parent | ¥28,964 million | ¥36,664 million |
| Total assets / net assets | - | ¥1,864,592 million / ¥497,640 million |
Consolidated sales are large probably because they include trading in precious metal bullion and raw material, and the value of recovery and refining work, but the statements give no breakdown of sales (bullion, industrial products, jewelry and so on), so this cannot be confirmed Not yet confirmed. On the balance sheet, inventories are ¥1,081.8 billion and borrowed bullion is ¥580.4 billion, showing how large holding and sourcing precious metal is. Changes in sales may therefore follow precious metal prices (Inference); they are not a measure of the size or growth of the hydrogen business. The company describes its corporate split of 1 January 2025 as a reorganization within the same group.
5. Resources committed to hydrogen
Hydrogen-only headcount and spending are not disclosed. The table covers four points (people, money, outside deals, universities and public funding) and shows what could and could not be confirmed.
| Item | What could be confirmed | Status |
|---|---|---|
| People (R&D sites, headcount) | Fuel cell catalyst R&D and production are at the FC Catalyst Development Center on the grounds of the Shonan plant (Hiratsuka, Kanagawa). Tanaka Kikinzoku Kogyo has 2,862 employees (31 December 2025). Hydrogen-only headcount and researcher numbers are not disclosed. Five named developers were credited for the award-winning catalyst (2025) | Sourced / not disclosed |
| Money (R&D, capex) | 2013: built a dedicated fuel cell catalyst plant (1,000 m² of floor space) at the Shonan plant for about ¥1 billion. 2018: added a new building of about 3,000 m² to the FC Catalyst Development Center, an investment of about ¥4 billion, raising production capacity about 7-fold (full operation announced for January 2019). 2024 to 2026: installed a 500 kW pure-hydrogen fuel cell power plant (the investment amount could not be confirmed). Hydrogen-only R&D spend is not disclosed | Sourced (individual projects) / not disclosed |
| Outside deals (investments, acquisitions, joint ventures, divestments) | September 2023: a technical assistance agreement with its Chinese affiliate, Chengdu Guangming Paite Precious Metals, on manufacturing technology for fuel cell electrode catalysts (production equipment to go in the plant of its subsidiary, Ya'an Guangming Paite Precious Metals, with production for the Chinese market planned within 2025). 30 July 2026: invested in Clean Planet Inc., which researches "quantum hydrogen energy" (the stake and amount could not be confirmed). No hydrogen-related acquisition or joint venture could be confirmed | Sourced / not confirmed (stake, amount) |
| Universities, research institutes, public funding | Under NEDO's "Advanced technology development for PEFC utilization" program (fiscal 2015 to 2019) it worked with the University of Yamanashi on a platinum-cobalt alloy hydrogen-electrode catalyst (2020). A joint study led by Kyoto University, with Tanaka, the research association FC-Cubic, Yokohama National University, Kyushu University, Nara Women's University, Shimane University and Ritsumeikan University, identified the active sites of iridium oxide catalysts (2025, published paper). It joined Kawasaki's carbon-neutral industrial-complex councils (2024). Individual public funding for electrolysis, such as the Green Innovation Fund, could not be confirmed | Sourced / not confirmed (electrolysis funding) |
Status of main projects
Tanaka does not build equipment, so its projects are mainly catalyst manufacturing facilities and its own use of hydrogen. Production volumes (tonnes a year) could not be confirmed for any of them from company sources.
| Project | Location | Scale | Stage | Date and source |
|---|---|---|---|---|
| Dedicated fuel cell catalyst plant ("mother plant") | Shonan plant (Hiratsuka, Kanagawa) | About 1,000 m² of floor space, about ¥1 billion | Completion announced for March 2013, full operation for October 2013 | 26 February 2013 |
| Expansion of the FC Catalyst Development Center | Shonan plant | New building of about 3,000 m², about ¥4 billion, capacity about 7 times higher | Announced for completion in July 2018 and full operation in January 2019. Its current operating status could not be confirmed | 10 July 2018 |
| Production of fuel cell catalysts for China | China, plant of Ya'an Guangming Paite Precious Metals | Not disclosed | Planned: production to start within 2025 (announced in 2023). Whether it started could not be confirmed | 12 September 2023 |
| 500 kW pure-hydrogen fuel cell power plant "TANAKA H2 Nexus" | Tanaka Kikinzoku Kogyo Shonan fuel cell power station (Hiratsuka) | 500 kW (Toshiba "H2Rex," 5 units of 100 kW). Overall efficiency 95% (LHV basis), design durability about 80,000 hours (both manufacturer's stated values) | Operating. At maximum output it can supply about 34% of the electricity used at the nearby Shonan plant (Tanaka's estimate) | 12 March 2024 (decision); 9 July 2026 (start) |
| Sample supply of palladium hydrogen-permeable membranes | - | HPM-L111: up to about 100 sheets a month | Sample-supply stage (from September 2025 and March 2026) | 12 September 2025; 5 March 2026 |
6. Track record
| When | What happened | Why it matters |
|---|---|---|
| 1885 and 1918 | Founded in Nihonbashi, Tokyo (as Ejimaya Tanaka Shoten) and incorporated in 1918. It grew with platinum as a main line | A long accumulation of precious-metal processing and recovery |
| 1985 | Began developing electrode catalysts for PEFCs (stated in releases of 2016 and 2026) | The starting point as a hydrogen materials supplier |
| 2011 | Received Ballard Power Systems' Best Supplier Award for 2010, for the fourth year running (the company's release) | Recognition by a fuel cell maker (company account) |
| 2013 | Built a dedicated fuel cell catalyst plant at the Shonan plant for about ¥1 billion (full operation planned for October) | A "mother plant" for scaling up |
| 2016 | Announced that its platinum electrode catalyst was adopted in Honda's fuel cell vehicle CLARITY FUEL CELL | An automotive adoption (company release) |
| 2018 | Showed a CCM for evaluating electrolysis electrode catalysts for the first time at FC EXPO (headline only confirmed). In July announced the expansion of the FC Catalyst Development Center (about ¥4 billion, capacity about 7 times) | Moving into electrolysis, and scaling up fuel cell catalysts |
| 2020 | With NEDO and the University of Yamanashi, developed a platinum-cobalt alloy hydrogen-electrode catalyst that cuts hydrogen peroxide formation to less than half (14 January). Selected as a METI Global Niche Top company for fuel cell catalysts (August) | Better durability; recognition of the business |
| September 2023 | Signed a technical assistance agreement on fuel cell electrode catalyst manufacturing with its Chinese affiliate | A plan to meet Chinese demand |
| March 2024 | Decided to install a 500 kW pure-hydrogen fuel cell power plant near its Shonan plant. Joined Kawasaki's carbon-neutral industrial-complex councils | Action as a hydrogen user |
| 2025 | Group reorganization on 1 January. June: received the Catalyst Manufacturers' Association technology award for "development and commercialization of electrode catalysts for PEM water electrolysis" (it says it mass-produced a catalyst with oxygen-evolution and hydrogen-recombination functions). August: joint research with Kyoto University and others published as a paper. September: PdCu39 hydrogen-permeable membrane usable at about 300 °C | Practical electrolysis catalysts; widening into hydrogen purification |
| 2026 | March: announced the Pd hydrogen-permeable membrane "HPM-L111" for about 100 °C (the company calls it a world first). 8 July: the 500 kW fuel cell plant began operating. 30 July: invested in Clean Planet. 9 September: announced its first exhibition at Hydrogen Technology World Expo 2026 in Germany (20 to 22 October) | A wider product range and overseas expansion |
7. Plans
Technology World Expo 202620 to 22 October 2026, Hamburg, Germany. Its first appearance there (announced plan)
(HPM-L111: up to about 100 sheets a month)No mass-production or price plan is stated
iridium useThe company says it works on iridium-reduced and H₂-leak-prevention catalysts. No dates or target figures
versus 2013A Tanaka group target; the 500 kW fuel cell plant is one measure (2024 release)
In its July 2026 release the company said that running the fuel cell plant would let it "accumulate knowledge and know-how on hydrogen use and apply it to future technology development and business expansion" Not yet confirmed. Company sources contain no sales or volume targets for fuel cell or electrolysis catalysts, no plan for a new plant, and no confirmation that production in China began.
None of the following appears in primary sources Not yet confirmed.
Hydrogen sales, profit and headcount / shipment volumes of fuel cell and electrolysis catalysts, and the basis for any market-share figure / current capacity after the 2018 expansion / whether production in China began within 2025 / sales and customer names for electrolysis catalysts / the investment in the 500 kW plant / the stake and amount of the Clean Planet investment / any plan to sell or exit hydrogen (the company has announced none).
8. What the company is aiming for in hydrogen
This section includes points the company does not state directly. It sets out inferences that the primary sources support, with the evidence.
| What can be read from the sources | Primary evidence | Status |
|---|---|---|
| It is extending the manufacturing capacity and electrochemical know-how built on fuel cell catalysts into materials for electrolysis, hydrogen purification and reforming, to supply the whole hydrogen value chain | 2026 release: "Building on more than 40 years of fuel cell catalyst development, we are expanding our business into electrolysis catalysts, hydrogen-permeable membranes, reforming catalysts and plated electrodes" | Sourced (company description) |
| In electrolysis it treats cutting iridium use and raising efficiency by thinning the PEM as its challenges | 2025 award release (a catalyst that allows a thinner membrane); 2026 exhibition release (aims to cut use of the scarce iridium); product page (iridium-reduced catalysts in development) | Sourced (company description) |
| It makes a one-stop system that includes recovery and recycling of precious metals a strength, to cope with swings in demand for hydrogen materials | 2026 release: "from sourcing of precious metals through material development, manufacturing, sales and recycling, all in one." The official recovery and refining business | Sourced (company description) |
| By being a user of hydrogen itself, it wants to understand customers' problems in real operation | July 2026 release: it can identify and share issues at the operating site, and will strengthen ties with partner companies | Sourced (company description) |
| It is also investing in start-ups in frontier fields to probe links to next-generation energy | July 2026 investment release: aims to gain knowledge; a very long-term vision looking to 2085, the company's 200th anniversary. The company itself treats the technology's feasibility and its relation to the hydrogen business as open | Inference |
The reading that "it is widening its materials to supply the whole hydrogen value chain" rests on the order in which products were added and the wording of each announcement. The 2013 and 2018 releases were mainly about expanding fuel cell electrode catalyst output. In 2018 it showed an evaluation CCM for electrolysis; in 2020 came the alloy catalyst for the hydrogen electrode; in 2025 the electrolysis catalyst award and the 300 °C Pd membrane; and in 2026 the 100 °C Pd membrane and the 500 kW fuel cell plant. The September 2026 exhibition release lists electrode catalysts, hydrogen purification, gas reforming, plated electrodes and recycling together as "technologies that support the hydrogen value chain." That is a presentation of assembling a material for each step of the hydrogen process from precious metal processing and recovery, rather than growing one product. The scale of each product's sales, however, is not disclosed, and which products actually support earnings cannot be confirmed from company sources Not yet confirmed.
9. Partnership map for hydrogen
A feature of Tanaka's relationships is that customers are named only in past announcements (Ballard in 2011, Honda in 2016). Company sources do not name the current customers for fuel cell or electrolysis catalysts. The company gives no reason, so this article does not guess. Research partners, by contrast, are named specifically (NEDO, the University of Yamanashi, Kyoto University, FC-Cubic, Yokohama National University and others). Joint development or supply contracts with electrolyzer makers could not be confirmed from company sources Not yet confirmed.
10. Technologies, products and services
What follows comes from the company's official product pages, press releases and the NEDO release. Values are the manufacturer's stated values, and values that depend on conditions are given with those conditions. Values measured under different conditions cannot be lined up to rank products Sourced.
| Product | What the company's pages say (manufacturer's stated values) |
|---|---|
| Platinum catalysts for PEFCs (Pt/C) | Standard grades carry 30 to 70 wt% platinum, on a high-surface-area carbon support (TEC10E40E [40%], TEC10E50E [50%], TEC10E60TPM [60%], TEC10E70TPM [70%]) or on VULCAN® XC72 (TEC10V30E [30%], V40E [40%], V50E [50%]). The company says it has developed grades that suppress Pt dissolution caused by load changes and grades with greater durability at high potential (no performance values given). Other supports, loadings and alloys are available on request |
| Platinum alloy catalysts for PEFCs (PtCo/C) | TEC36E32 (30 wt% Pt) and TEC36E52 (50 wt%), on a high-surface-area carbon support. The company says it "optimized the alloy-catalyst loading process and developed a PtCo catalyst with high oxygen reduction activity" (no activity figures) |
| Platinum-ruthenium catalysts for PEFCs (PtRu/C) | For the anode. TEC61E54 and TEC61E54-HT2 (54 wt% loading, Pt:Ru molar ratio 1:1.5) and TEC62E58-HT (58 wt%, 1:2). Described as having excellent resistance to carbon monoxide poisoning and as the standard anode catalyst for reformed hydrogen fuel |
| Iridium oxide catalysts for PEM electrolysis (anode) | TEC77100 (high activity): Ir content 76 wt%, specific surface area 90 to 120 m²/g, average crystallite size 10 to 20 Å, degradation rate 5 to 40 µV/h. TEC77110 (high durability): Ir content 86 wt%, 40 to 70 m²/g, 20 to 40 Å, 0 to 10 µV/h. The degradation rate is noted as measured at a cell temperature of 50 °C and a constant current of 2.0 A/cm² (test duration, cell configuration and membrane are not stated). Pt-based cathode catalysts are also offered |
| Dual-function catalyst for PEM electrolysis (OER + GRC) | A catalyst with two functions: oxygen evolution (OER) and a gas recombination catalyst (GRC) that recombines hydrogen and oxygen. The company says it lowers the hydrogen concentration on the anode side, suppresses "hydrogen crossover" and allows a thinner PEM. It announced in 2025 that it had been mass-produced and could be supplied to customers in Japan and abroad (no efficiency or membrane-thickness figures) |
| Precious-metal-plated electrodes (GDL and PTL for PEM electrolysis; insoluble electrodes) | Pt or PtIr electroplated on titanium. Substrates include expanded metal (minimum opening 2.0 mm × 1.0 mm), micro-mesh and porous bodies (sintered fiber and sintered powder). A 0.1 µm platinum film is shown as an example. Gold plating and iridium oxide coatings are also available |
| Reforming, shift and PROX catalysts; ammonia-cracking catalysts | Steam reforming catalysts (Ru, Rh) for equipment that makes hydrogen from city gas and similar fuels, plus shift and PROX catalysts (which remove CO down to a few ppm), offered as a set. Ammonia-cracking catalysts (Ru, Pt) and catalysts that decompose NOx and N₂O from ammonia-containing exhaust are also offered. Performance values for these were not checked individually for this article |
| Palladium hydrogen-permeable membranes | Rolled foil and tube. PdCu39 (2025): a proprietary heat treatment gives a fully bcc phase and allows use at about 300 °C. HPM-L111 (2026): a surface treatment gives a metal membrane that shows high hydrogen permeation at around 100 °C (the company calls it a world first). Samples up to about 100 sheets a month. Pinhole-free thin membranes |
| Recovery and refining of precious metals | Recovers and refines precious metals from used catalysts and similar material and turns them back into products. The company says its industrial business covers sourcing, material development, manufacturing, sales and recycling in one chain |
(1) In fuel cells, how platinum is placed, and how it withstands harsh operation, count more than how much is used. The standard Pt/C grades are split by loading (30 to 70 wt%) and support (high-surface-area carbon, VULCAN® XC72). In general a higher loading allows a thinner electrode layer, but particles tend to cluster, and the support changes dispersion and durability (our general summary). The company says it developed grades that suppress platinum dissolution under load changes and grades with better durability at high potential, but no performance values (mass activity, electrochemical surface area, durability test results) are on the public pages Not yet confirmed. See our explainers on platinum group metals and catalysts and on fuel cell vehicles and polymer electrolyte fuel cells.
(2) Alloying the hydrogen electrode (anode) cuts off one way the membrane breaks. The 2020 release from NEDO, the University of Yamanashi and Tanaka Kikinzoku Kogyo focused on a degradation path in the fuel cell anode: hydrogen peroxide forms, and the radicals it generates decompose the electrolyte membrane. With a PtCo alloy catalyst having a platinum-skin layer (the mass-synthesized "PtCo/C HT") at the anode, hydrogen peroxide generation fell to less than half, and in an accelerated degradation test the time to fall to 0.85 V or below was more than four times that with a commercial Pt/CB catalyst. These values are conditional: a 25 µm electrolyte membrane, a commercial Pt/GCB HT cathode, a single cell with an electrode area of 29.2 cm², and pressurized reaction gases at 90 °C in open-circuit conditions (hydrogen permeation measured every 200 hours). They do not describe vehicle service life. It is an example in which anode catalyst design affects membrane life.
(3) In electrolysis, the iridium's specific surface area and crystallite size mark the split between activity and durability. In the company's stated values, the high-activity grade (TEC77100) has a large surface area (90 to 120 m²/g) and small crystallites (10 to 20 Å) with a degradation rate of 5 to 40 µV/h, while the high-durability grade (TEC77110) has a smaller surface area (40 to 70 m²/g), larger crystallites (20 to 40 Å) and a degradation rate of 0 to 10 µV/h. The pairing suggests a trade-off between activity and durability (this is our reading of the two grades' figures; the company does not use the word "trade-off"). These figures are stated values at 50 °C and a constant 2.0 A/cm² and cannot be compared with other conditions or other makers' values. The joint study with Kyoto University and others reports that operando X-ray absorption spectroscopy and other methods revealed the origin of the high activity of iridium oxide catalysts (Journal of the American Chemical Society, 2025). See our explainers on PEM water electrolysis and on electrolyzer stacks and materials.
(4) A catalyst can suppress "hydrogen crossover" and let the membrane be thinner. If hydrogen made at the cathode crosses the membrane to the anode, it mixes with oxygen and becomes hazardous. The usual remedy was a thicker membrane, which added resistance and lowered efficiency. The company's dual-function catalyst recombines hydrogen and oxygen at the anode to lower the hydrogen concentration, which it says allows a thinner membrane (no efficiency or thickness figures). It is an example in which adding a function to the catalyst widens the design freedom for membrane and cell, but the actual size of the improvement cannot be confirmed from public sources Not yet confirmed.
(5) For plated electrodes, the skill is to use precious metal thinly and only where needed. The company points to examples such as a 0.1 µm platinum film on a titanium substrate, and to partial plating and re-plating to reduce the amount of precious metal used. The substrates differ in character: low-cost expanded metal, micro-mesh with a smooth surface, and porous bodies expected to supply gas uniformly. The company says the smooth surface of the micro-mesh is expected to ease physical damage when it is joined to the catalyst coated membrane (CCM).
(6) For palladium membranes, controlling the phase lowers the operating temperature. In PdCu alloy membranes even a small amount of fcc phase sharply reduces hydrogen permeation, so a heat treatment that yields a fully bcc phase is the key, the company said in 2025. The 2026 HPM-L111 is described as enabling hydrogen permeation even at about 100 °C through a surface treatment of the membrane (permeability coefficient, purity and durability figures could not be confirmed from public sources). Hydrogen purification is subject to laws and standards, and this article is not handling advice.
11. Risks
| Risk | Detail | Status |
|---|---|---|
| The size and results of the hydrogen business are not visible | Hydrogen sales, profit and headcount, and catalyst shipment volumes, are not disclosed. No third-party figure backs the company's claims such as "world-leading" | Not yet confirmed |
| Slow demand build-up | Demand for catalysts depends on the uptake of fuel cell vehicles, stationary fuel cells and electrolyzers. The company's sources do not give an outlook for hydrogen demand, and the largest customer for fuel cell supply cannot be identified | Inference |
| Plans that cannot be checked | The start of production for China (planned within 2025) and the operating status after the 2018 expansion cannot be confirmed in later official sources | Not yet confirmed |
| Precious metal prices and supply | It uses platinum, iridium, ruthenium, rhodium and palladium, and the company itself says iridium is especially scarce. Large inventories and borrowed bullion on the balance sheet leave it open to price swings | Sourced (company description) / Inference |
| Progress in cutting iridium use | If iridium-reduced catalysts advance, demand for iridium oxide catalysts could change in structure. The company also treats reduction as a challenge, but the timing is not disclosed | Inference |
| Competition and in-house production by customers | Fuel cell and electrolyzer makers might make catalysts themselves or buy them from other materials companies. Competitor activity is not covered in company sources, and this article does not assess it | Inference |
| Commercializing new technologies | The Pd hydrogen-permeable membranes are at the sample stage (about 100 sheets a month); mass production, price and customers are unconfirmed. The Clean Planet investment is an exploratory step that the company itself describes as aimed at "gaining knowledge," and its relation to the business is open | Not yet confirmed |
| Group structure and disclosure | Several legal entities, no listing, and no business-segment financials. It is necessary to check whether a figure belongs to the parent, the management company or the operating company | Sourced |
12. Glossary
- Platinum group metals (PGMs)
- Platinum, palladium, rhodium, iridium, ruthenium and osmium. Valuable metals widely used as catalysts.
- PEFC
- Polymer electrolyte fuel cell. It makes electricity from hydrogen and oxygen and is used in fuel cell vehicles, among other uses.
- PEM water electrolysis
- Splitting water into hydrogen and oxygen using a proton exchange membrane (a solid polymer membrane).
- Electrode catalyst
- A catalyst that speeds up the electrode reaction. In fuel cells and electrolysis it is a powder of platinum or iridium particles on a support.
- Support (carbon)
- The base particle on which catalyst metal particles are placed. High-surface-area carbon or carbon black such as VULCAN® XC72 is used.
- Alloy catalyst (PtCo, PtRu)
- A catalyst where platinum is mixed with another metal. PtCo is used for oxygen reduction and to curb hydrogen-electrode degradation; PtRu for resistance to carbon monoxide.
- OER / HER
- In water electrolysis, the oxygen evolution reaction (OER) at the anode and the hydrogen evolution reaction (HER) at the cathode.
- GDL / PTL
- Gas diffusion layer / porous transport layer. A layer that spreads gas and water evenly over the electrode and conducts electricity. Tanaka offers titanium parts plated with precious metal.
- Hydrogen crossover
- In electrolysis, hydrogen from the cathode passing through the membrane to the anode side. Mixing with oxygen is hazardous, and the conventional remedy is a thicker membrane.
- Hydrogen-permeable membrane
- A metal membrane that passes only hydrogen. Palladium alloys are used. It is used to purify hydrogen.
- Reforming / shift / PROX
- Steps for making hydrogen from city gas and similar fuels: reforming makes hydrogen and CO, the shift step reduces CO, and PROX removes it further to a few ppm.
- Manufacturer's stated value
- A performance value given by the maker itself. It cannot be compared with another product unless test conditions and versions match.
13. References
- Tanaka Kikinzoku Tanaka Kikinzoku Kogyo K.K. (group company list, official site; in Japanese). Company profile (capital, sales, employees, head office). https://www.tanaka.co.jp/company/group/tkk/
- Tanaka Kikinzoku Group company list (official site; in Japanese). Relations between Tanaka Kikinzoku Group and its subsidiaries. https://www.tanaka.co.jp/company/group/
- Tanaka Kikinzoku Financial information (official site; in Japanese). Publication of statutory financial statements. https://www.tanaka.co.jp/company/financial/
- Field In & Company Co., Ltd. (formerly TANAKA Holdings) Consolidated financial statements, 161st term (FY2025) (PDF; in Japanese). Consolidated results, consolidated subsidiaries, corporate split and name change. https://www.tanaka.co.jp/company/assets/pdf/161_2025_01.pdf
- TANAKA Holdings (now Field In & Company) Consolidated financial statements, 160th term (FY2024) (PDF; in Japanese). https://www.tanaka.co.jp/company/assets/pdf/160_2024_01.pdf
- Tanaka Kikinzoku Group Tanaka Kikinzoku Group Co., Ltd., financial statements for the 2nd term (FY2025) (PDF; in Japanese). Relation to the parent company. https://www.tanaka.co.jp/company/assets/pdf/161_2025_02.pdf
- Tanaka Kikinzoku History (official site; in Japanese). Chronology from the founding to 2026. https://www.tanaka.co.jp/company/history/
- Tanaka Kikinzoku Kogyo Electrode catalysts for fuel cells and for water electrolysis (product page; in Japanese). https://tanaka-preciousmetals.com/jp/products/pefcs.html
- Tanaka Kikinzoku Kogyo Precious metal plated electrodes (GDL and insoluble electrodes for PEM water electrolysis) (product page; in Japanese). https://tanaka-preciousmetals.com/jp/products/plating_electrode.html
- Tanaka Kikinzoku Kogyo Reforming, shift and PROX catalysts (product page; in Japanese). https://tanaka-preciousmetals.com/jp/products/reforming_shift_reaction_prox_catalyst.html
- Tanaka Kikinzoku Kogyo Ammonia-related catalysts (product page; in Japanese). https://tanaka-preciousmetals.com/jp/products/nh3_catalyst.html
- Tanaka Kikinzoku Kogyo Hydrogen-permeable membranes (product page; in Japanese). https://tanaka-preciousmetals.com/jp/products/hydrogen_permeable_films.html
- TANAKA Holdings Tanaka Kikinzoku Kogyo to build a dedicated plant for developing and making fuel cell catalysts (26 February 2013; PDF, in Japanese). https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20130226_01.pdf
- TANAKA Holdings Tanaka Kikinzoku Kogyo expands its FC Catalyst Development Center (10 July 2018; PDF, in Japanese). https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20180710_01.pdf
- TANAKA Holdings Tanaka's platinum electrode catalyst adopted in Honda's new fuel cell vehicle CLARITY FUEL CELL (12 May 2016; PDF, in Japanese). https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20160512_01.pdf
- TANAKA Holdings Tanaka Kikinzoku Kogyo wins Ballard Power Systems' best supplier award for fuel cell catalysts (10 May 2011; PDF, in Japanese). https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20110510_01.pdf
- Tanaka Kikinzoku Kogyo World's first: a platinum-cobalt alloy hydrogen-electrode catalyst that greatly suppresses fuel cell degradation (14 January 2020; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20200114.html
- NEDO Joint release with the University of Yamanashi and Tanaka Kikinzoku Kogyo (14 January 2020; in Japanese). Pt-Co alloy hydrogen-electrode catalyst and the conditions of the accelerated degradation test. https://www.nedo.go.jp/news/press/AA5_101266.html
- Tanaka Kikinzoku Kogyo Selected as a 2020 METI-certified Global Niche Top company (4 August 2020; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20200804.html
- Tanaka Kikinzoku Kogyo Establishes a production system for fuel cell electrode catalysts in China (12 September 2023; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20230912.html
- Tanaka Kikinzoku Group Introduces one of Japan's largest 500 kW fuel cell power plants (12 March 2024; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20240312.html
- Tanaka Kikinzoku Kogyo Wins the 2025 Catalyst Manufacturers' Association technology award for electrode catalysts for PEM water electrolysis (6 June 2025; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20250606.html
- Tanaka Kikinzoku Kogyo / Kyoto University and others Notice of joint research with Kyoto University (20 August 2025; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20250820.html
- Thakur et al. Identifying Active Sites of IrOx Catalysts for OER: A Combined Operando XAS, SEIRAS, and Theoretical Study, Journal of the American Chemical Society 147, 30613-30625 (2025). DOI 10.1021/jacs.4c18510 (confirmed through Crossref). https://doi.org/10.1021/jacs.4c18510
- Tanaka Kikinzoku Kogyo Develops a high-performance palladium alloy hydrogen-permeable membrane usable at 300 °C (12 September 2025; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20250912.html
- Tanaka Kikinzoku Kogyo World's first palladium hydrogen-permeable membrane with high permeation at around 100 °C (5 March 2026; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20260305.html
- Tanaka Kikinzoku Kogyo Starts operating the 500 kW fuel cell power plant "TANAKA H2 Nexus" (9 July 2026; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20260709.html
- Tanaka Kikinzoku Group Investment in Clean Planet (30 July 2026; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20260730-1.html
- Tanaka Kikinzoku Kogyo First exhibition at Hydrogen Technology World Expo 2026 (9 September 2026; in Japanese). https://tanaka-preciousmetals.com/jp/news/press_release/20260909.html
- TANAKA Corporate website (source of the official English logo). TANAKA Corporate Website (English)
14. Claim-to-source audit
| Claim in the text | Status | Source |
|---|---|---|
| Company profile of Tanaka Kikinzoku Kogyo (capital of ¥500 million, sales of ¥419,177,145,000 in FY2025, 2,862 employees at 31 December 2025, head office, business, founded 1885 and incorporated 1918) | Sourced | Reference 1 https://www.tanaka.co.jp/company/group/tkk/ |
| The group's legal structure (Tanaka Kikinzoku Kogyo and others as wholly owned subsidiaries of Tanaka Kikinzoku Group) | Sourced | Reference 2 https://www.tanaka.co.jp/company/group/ |
| Financial information is published as statutory financial statements (PDF) | Sourced | Reference 3 https://www.tanaka.co.jp/company/financial/ |
| Consolidated net sales of ¥1,097,813 million, operating profit of ¥44,517 million, ordinary profit of ¥51,853 million, net profit of ¥36,664 million, total and net assets, inventories, borrowed bullion, 39 consolidated subsidiaries and 8 equity-method affiliates, the corporate split and name change of 1 January 2025 | Sourced | Reference 4 https://www.tanaka.co.jp/company/assets/pdf/161_2025_01.pdf |
| Consolidated net sales of ¥846,921 million, operating profit of ¥30,312 million, ordinary profit of ¥37,906 million and net profit of ¥28,964 million for the year to December 2024 | Sourced | Reference 5 https://www.tanaka.co.jp/company/assets/pdf/160_2024_01.pdf |
| Tanaka Kikinzoku Group is wholly owned by the parent (Field In & Company); statements for its 2nd term | Sourced | Reference 6 https://www.tanaka.co.jp/company/assets/pdf/161_2025_02.pdf |
| History (the 2010 holding-company structure, the 2024 establishment of Tanaka Kikinzoku Group, the 2025 move to a new structure, 2026 organizational changes) | Sourced | Reference 7 https://www.tanaka.co.jp/company/history/ |
| PEFC catalyst part numbers, loadings, supports and Pt:Ru ratios; stated values for the iridium oxide electrolysis catalysts TEC77100 and TEC77110 (Ir content, surface area, crystallite size, degradation rate; conditions of 50 °C cell temperature and 2.0 A/cm²); description of the dual-function catalyst | Sourced (manufacturer's stated value) | Reference 8 https://tanaka-preciousmetals.com/jp/products/pefcs.html |
| Precious-metal-plated electrodes (titanium substrate, Pt and PtIr, kinds of substrate, minimum opening 2.0 mm × 1.0 mm, example of 0.1 µm platinum) | Sourced (manufacturer's stated value) | Reference 9 https://tanaka-preciousmetals.com/jp/products/plating_electrode.html |
| Description of reforming, shift and PROX catalysts (Ru, Rh) | Sourced (company description) | Reference 10 https://tanaka-preciousmetals.com/jp/products/reforming_shift_reaction_prox_catalyst.html |
| Ammonia-cracking catalysts and catalysts for decomposing NOx and N₂O in ammonia-containing exhaust (Ru, Pt) | Sourced (company description) | Reference 11 https://tanaka-preciousmetals.com/jp/products/nh3_catalyst.html |
| Hydrogen-permeable membrane product page (Pd alloy, rolled foil and tube, pinhole-free) | Sourced (company description) | Reference 12 https://tanaka-preciousmetals.com/jp/products/hydrogen_permeable_films.html |
| The 2013 dedicated fuel cell catalyst plant (about ¥1 billion, 1,000 m² of floor space, Shonan plant) | Sourced (2013 plan) | Reference 13 https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20130226_01.pdf |
| The 2018 expansion of the FC Catalyst Development Center (new building of about 3,000 m², about ¥4 billion, capacity about 7 times, full operation planned for January 2019) | Sourced (2018 plan) | Reference 14 https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20180710_01.pdf |
| Adoption in Honda's CLARITY FUEL CELL; development since 1985 | Sourced (company release) | Reference 15 https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20160512_01.pdf |
| Ballard's Best Supplier Award for 2010, won four years running | Sourced (company release) | Reference 16 https://tanaka-preciousmetals.com/jp/news/sites/topics/jp/20110510_01.pdf |
| The Pt-Co alloy hydrogen-electrode catalyst with NEDO and the University of Yamanashi (hydrogen peroxide generation cut to less than half; accelerated degradation test conditions; time to 0.85 V or below more than four times longer); NEDO program name and period (fiscal 2015 to 2019) | Sourced | Reference 17, 18 https://tanaka-preciousmetals.com/jp/news/press_release/20200114.html https://www.nedo.go.jp/news/press/AA5_101266.html |
| Selected as a METI Global Niche Top company for fuel cell catalysts (2020) | Sourced | Reference 19 https://tanaka-preciousmetals.com/jp/news/press_release/20200804.html |
| Technical assistance agreement with the Chinese affiliate (September 2023; Ya'an Guangming Paite plant; production planned within 2025) | Sourced (2023 plan) | Reference 20 https://tanaka-preciousmetals.com/jp/news/press_release/20230912.html |
| Decision to install a 500 kW pure-hydrogen fuel cell (March 2024), CO₂ reduction target, joining Kawasaki's councils, estimate of the effect | Sourced (company description) | Reference 21 https://tanaka-preciousmetals.com/jp/news/press_release/20240312.html |
| The 2025 Catalyst Manufacturers' Association technology award (electrode catalysts for PEM electrolysis; dual OER and GRC function; mass production; suppression of hydrogen crossover) | Sourced (company description) | Reference 22 https://tanaka-preciousmetals.com/jp/news/press_release/20250606.html |
| Joint research with Kyoto University and seven other organizations; identification of active sites of iridium oxide catalysts; bibliographic details of the paper | Sourced | Reference 23, 24 https://tanaka-preciousmetals.com/jp/news/press_release/20250820.html https://doi.org/10.1021/jacs.4c18510 |
| PdCu39 hydrogen-permeable membrane (about 300 °C, fully bcc phase, 2025) | Sourced (company description) | Reference 25 https://tanaka-preciousmetals.com/jp/news/press_release/20250912.html |
| HPM-L111 (about 100 °C, claimed world first, about 100 sheets a month of samples, 2026) | Sourced (company description) | Reference 26 https://tanaka-preciousmetals.com/jp/news/press_release/20260305.html |
| Start of TANAKA H2 Nexus (8 July 2026; 500 kW; 5 units of 100 kW; overall efficiency 95%; design durability of about 80,000 hours; about 34% of the Shonan plant's electricity) | Sourced (manufacturer's stated value, company estimate) | Reference 27 https://tanaka-preciousmetals.com/jp/news/press_release/20260709.html |
| Investment in Clean Planet (30 July 2026) and the very long-term vision looking to 2085 | Sourced (company release) | Reference 28 https://tanaka-preciousmetals.com/jp/news/press_release/20260730-1.html |
| First exhibition at Hydrogen Technology World Expo 2026 (20 to 22 October 2026), products across the hydrogen value chain, development since 1985, widening of business areas | Not yet confirmed | Reference 29 https://tanaka-preciousmetals.com/jp/news/press_release/20260909.html |
| The official English logo was taken from the header of the corporate website | Sourced | Reference 30 TANAKA Corporate Website (English) |
| Hydrogen-only sales, profit, headcount and R&D; shipment volumes; current operating status after the 2018 expansion; confirmation of production in China; sales and customers for electrolysis catalysts; investment in the 500 kW plant; the stake and amount of the Clean Planet investment; named public funding for electrolysis; an official statement that the company is unlisted | Not yet confirmed | Not stated in company sources. This article does not claim they do not exist (this article) |
| The readings that "it is widening its materials to supply the whole hydrogen value chain" and that "investing in frontier start-ups is a probe of next-generation energy"; that sales changes may follow precious metal prices; changes in demand structure from reducing iridium; customer and competitor shifts | Inference | Reference 4, 8, 22, 28, 29 https://www.tanaka.co.jp/company/assets/pdf/161_2025_01.pdf https://tanaka-preciousmetals.com/jp/products/pefcs.html https://tanaka-preciousmetals.com/jp/news/press_release/20250606.html https://tanaka-preciousmetals.com/jp/news/press_release/20260730-1.html https://tanaka-preciousmetals.com/jp/news/press_release/20260909.html |
| The classification of Tanaka Kikinzoku as "Materials & components" and the four-type framework | Our calculation | Our own arrangement and calculation (technical explanations are general and are not values for the company's products; see the technical explainers in this series) |
| The reading of an "activity versus durability trade-off" from the two electrolysis grades (TEC77100 and TEC77110) | Our calculation | Our own arrangement and calculation (technical explanations are general and are not values for the company's products; see the technical explainers in this series) |
| Technical explanations of supports, alloying, hydrogen crossover, plated electrodes and the phases of Pd membranes | Our calculation | Our own arrangement and calculation (technical explanations are general and are not values for the company's products; see the technical explainers in this series) |
Last updated: 6 October 2026 / Troy Technical
This article is based on the statutory financial statements published by the Tanaka Kikinzoku group, its official press releases and product pages, and releases from NEDO and Kyoto University and others. It uses no market-research estimates or press-based figures. Statements of market standing such as "world-leading" are the company's own, and we have not checked them against third parties. Items marked "Inference" are our reading of the primary sources and are not company disclosures. Product performance values are the manufacturer's stated values, given only with their conditions, and are not specification limits or guarantees. Company plans and targets are not yet confirmed and are not guaranteed. This article does not advise individual readers on handling or operating hydrogen, or on investment decisions.