Start with the target reaction
Chlorine evolution, oxygen evolution, metal deposition or oxidation of a contaminant. The reaction decides which coating family is even worth reviewing.
Coating Technology
Coating Systems for Titanium Anodes
The coating is the functional part of a titanium anode. This page compares the four coating systems we supply and shows which one has to be reviewed against a given process window.
How The Families Relate
MMO Contains Ru-Ir and Ir-Ta — It Is Not a Separate Level
Mixed metal oxide is the coating family. Ru-Ir and Ir-Ta are specific oxide combinations inside that family, not competitors to it. A Ru-Ir anode and an Ir-Ta anode are therefore both MMO anodes, and both are also MMO geometry products, because the coating chemistry and the shape of the electrode are two independent questions. The same anode can be described as an MMO titanium anode, as a Ru-Ir coated anode and as a tubular anode at the same time. Which description a buyer needs depends on whether the decision is about the surface, the shape or the application.
Ru-Ir Mixed Metal Oxide
Chlorine evolution, electrochlorination and hypochlorite generation
Review this coating →Ir-Ta and Ir-Based Mixed Metal Oxide
Oxygen evolution and selected advanced oxidation duties
Review this coating →Platinized Titanium
Precious metal plating, hard chrome plating and selected electrolysis
Review this coating →Specialty Coated Titanium
Advanced oxidation and project-specific electrochemical duties
Review this coating →Comparison
Compare The Coating Systems Against The Process Window
A coating name is not a specification. The reaction, the media, the current basis and the factor that normally limits the service life are what separate one family from another.
| Coating Family | Commonly Reviewed For | Media | Current Basis | What Limits The Life |
|---|---|---|---|---|
| Ru-Ir Mixed Metal Oxide | Chlorine evolution, electrochlorination and hypochlorite generation | Chloride brines, seawater and chloride-bearing process streams | Stated per unit of coated active area for the reviewed electrolyte | Impurity load, chloride level, pH and operating temperature |
| Ir-Ta and Ir-Based Mixed Metal Oxide | Oxygen evolution and selected advanced oxidation duties | Alkaline and acidic electrolytes, including water treatment matrices | Stated per unit of coated active area under the defined potential or current duty | Electrolyte composition, contaminant behaviour and mass transfer |
| Platinized Titanium | Precious metal plating, hard chrome plating and selected electrolysis | Plating baths and defined electrolysis media | Defined by the platinum metric, its coverage and the active area | Bath chemistry, polarity, current density and mechanical wear |
| Specialty Coated Titanium | Advanced oxidation and project-specific electrochemical duties | Case-by-case, defined by the complete process matrix | Stated per unit of coated area against a qualification basis | Defined by the pilot or qualification programme and the disposal route |
Selection Path
Four Steps To A Reviewable Specification
The order of these steps matters. Naming the coating first is what produces quotations that cannot be compared with each other.
Define the complete media
Composition, concentration, contaminants, pH, temperature and flow. A coating name without the full matrix cannot be accepted as a selection.
State the electrical duty
Current, voltage, waveform, polarity, daily operating schedule and the current-density basis expressed per unit of coated active area.
Choose the geometry
Only after the surface is fixed does the shape follow from the installation. The eight MMO geometries are reviewed from their own pages.
The geometry comes last
Once the active surface is fixed, the shape follows from the installation. The eight MMO geometries — linear, wire, ribbon, mesh ribbon, canister, tubular, disc and rod — are reviewed on their own pages.
Coating Family Pages
Open The Coating System You Need
Each coating page states the reactions it is commonly reviewed for, the inputs that change the decision and the geometry it is supplied in.
Ru-Ir Mixed Metal Oxide
Chloride brines, seawater and chloride-bearing process streams
Review Ru-Ir Mixed Metal Oxide →Ir-Ta and Ir-Based Mixed Metal Oxide
Alkaline and acidic electrolytes, including water treatment matrices
Review Ir-Ta and Ir-Based Mixed Metal Oxide →Platinized Titanium
Plating baths and defined electrolysis media
Review Platinized Titanium →Specialty Coated Titanium
Case-by-case, defined by the complete process matrix
Review Specialty Coated Titanium →FAQ
Coating System Questions
Is a Ru-Ir anode the same product as an MMO anode?
A Ru-Ir anode is an MMO anode: the ruthenium and iridium oxide combination is one of the mixed metal oxide systems inside the MMO family. They are described separately on this site because the coating chemistry drives the reaction it suits, not because they belong to different product categories.
Can a platinized titanium anode be used where an MMO anode is used?
Sometimes, but the comparison has to be made on the same basis. Platinum brings a different cost structure, a different wear behaviour and a different metric, so a platinized electrode should not be specified just because it is described as a more inert surface. The duty, the media and the expected wear have to be reviewed together.
Why is coating loading not comparable between suppliers?
Because loading and thickness are different characteristics, each with its own units, measurement method, sampling plan and acceptance criteria. A loading figure quoted without its method cannot be compared against another supplier, and a test result on one characteristic is not proof of the others.
Send Details
Describe The Reaction And The Media
Target reaction, electrolyte composition, contaminants, pH, temperature, current density with its active-area basis, geometry and the required life. A complete specification is not required for the first review.