Platinum mesh is platinum-rhodium or pure platinum wire woven or knitted into an open screen, sold mainly as the 90Pt/10Rh ammonia-oxidation catalyst gauze used in nitric acid production and as fine-wire electrodes for laboratory electrochemistry. It ships in a documented purity range from 99.9% to 99.999% for pure platinum forms, while the dominant catalytic product is specified by alloy composition instead of a fineness grade. This page covers where PGM products like platinum mesh sit, then its purity grades, manufacturing, uses, price basis and supplier types.
What Is Platinum Mesh?#
Platinum mesh is refined platinum, symbol Pt, atomic number 78, CAS 7440-06-4, drawn into fine wire and then woven or knitted into an open screen. This page treats it as one of several fabricated forms of platinum (Pt), element 78, distinguished by porosity: the mesh geometry maximizes surface area per gram and lets gas pass through the weave, which is why its two dominant uses, catalytic gauze and electrochemical electrodes, both depend on gas or ions reaching the metal surface, not only an outer face. That open lattice of wire, not a different purity or alloy, separates mesh from platinum's other wrought forms.
Platinum Mesh Purity Grades and Specifications#
Platinum mesh ships in two specification families, one governed by metal purity and one by alloy composition, because its two dominant applications need different things from the wire. Pure platinum mesh, for laboratory electrodes and general fabrication, follows the same purity ladder as other refined platinum, 99.9% up to 99.999%, with ASTM B561 naming two grades explicitly for refined platinum sponge, cast bar and wrought forms. Ammonia-oxidation catalyst gauze, by contrast, is never sold as pure platinum; it is woven or knitted from a platinum-rhodium alloy, because rhodium raises both mechanical strength and the reaction's NO yield, and no public standard governs that alloy's composition.
| Grade or alloy | Max total impurities (ppm) | Typical dimension | Named standard |
|---|---|---|---|
| 99.9% (3N) | ≤1,000 | General fabrication wire | No published standard for mesh specifically |
| 99.95% (3N5) | ≤500 | Wholesale-grade feedstock wire | ASTM B561 Grade 99.95 (UNS P04995) |
| 99.99% (4N) | ≤100 | Catalyst-precursor and lab-grade wire, 0.06-0.12 mm diameter | ASTM B561 Grade 99.99 |
| 99.999% (5N) | ≤10 | Reference and specialty electrode wire | No published standard for mesh specifically |
| 90Pt/10Rh (catalytic alloy) | Not fineness-graded; alloy composition governs | Wire diameter 0.060 mm or 0.076 mm | No public standard; patent literature (EP0259966A1, US5232891A) |
| PtRh5, 95Pt/5Rh (catalytic alloy) | Not fineness-graded; alloy composition governs | Wire diameter 76 µm, areal weight ~600 g/m² | No public standard; patent literature |
How Platinum Mesh Is Manufactured#
Platinum mesh starts from refined platinum sponge and is drawn, then woven or knitted, into its final screen form, in four steps:
- Reduce a precipitated platinum salt with hydrogen to yield platinum sponge at a minimum 99.95% purity, per Umicore's documented refinery output.
- Cast or sinter the sponge into an ingot suitable for wire drawing.
- Draw the ingot into fine wire, 0.060 mm to 0.076 mm diameter for catalytic gauze, from a pre-alloyed 90Pt/10Rh or 95Pt/5Rh melt rather than pure platinum.
- Weave or knit the wire into the finished pack. Modern gauzes are predominantly knitted rather than plain-woven, giving a three-dimensional structure and better gas mixing; per Heraeus, each pack is custom-designed per plant, its gauzes selected by weight, wire diameter and mesh count.
What Is Platinum Mesh Used For?#
Platinum mesh's primary use is as the ammonia-oxidation catalyst gauze that converts ammonia to nitric oxide in nitric acid manufacture, a reaction platinum and rhodium can run as bare metal in flowing air above 1200°C, a temperature that would oxidize away nearly every other platinum group metal in the same service. Its second major use is as an inert electrode in laboratory electrochemistry, where the open geometry offers more surface area per gram than solid wire or foil.
- Ammonia-oxidation catalysis: the dominant use, covered in full below.
- Andrussow-process HCN production, on the same Pt-Rh gauze hardware and suppliers as nitric acid plants.
- Electrochemical electrodes, covered in full below.
Platinum Mesh Price Basis#
The price of platinum mesh is the platinum metal value at order time, converted to the buyer's weight unit, plus a fabrication premium. That metal value is the live platinum spot price, not a number this page states directly.
Platinum Mesh price = (platinum spot price per troy ounce / 31.1034768) x weight in grams
+ fabrication premium (form, dimension, purity grade, order quantity)
No premium percentage is published here, because the facts ledger carries no sourced figure for mesh specifically; buyers see the premium quoted at order time. Fabricators scale that premium against a base platinum price per gram for small orders and against the platinum price per kilogram for bulk gauze-pack quantities.
Platinum Mesh as an Electrode#
Platinum mesh is used as a counter or working electrode because platinum resists oxidation and chemical attack better than almost any other conductor, documented at its most extreme in platinum and rhodium being the only two platinum group metals usable as bare metal in flowing air above 1200°C, a resistance that holds in most aqueous electrolytes too. The open structure adds a benefit specific to this form: more surface per gram than a solid wire, and perforations that let electrolysis gas bubbles escape instead of blanketing the metal.
Platinum Mesh in Nitric Acid Gauze Catalysis#
Platinum mesh for ammonia oxidation is woven or knitted from a platinum-rhodium alloy at a mesh count set by the plant's operating pressure, not from pure platinum. High-pressure plants (10-13 barg) run the classical binary 90Pt/10Rh alloy, first patented by DuPont in 1929, at roughly 1,024 mesh per square centimeter. Medium-pressure plants (3-7 barg) instead favor PtRh5 (95Pt/5Rh) at 76 micrometers, about 600 g/m² areal weight, a range SFA (Oxford) corroborates for the International Platinum Group Metals Association, which puts binary gauze rhodium content at 3% to 10%.
| Alloy | Composition | Mesh density or areal weight | Wire diameter | Pressure regime |
|---|---|---|---|---|
| Pt-10%Rh (binary) | 90% Pt / 10% Rh | ~1,024 mesh/cm² | 0.060 mm or 0.076 mm | High pressure, 10-13 barg |
| PtRh5 (binary) | 95% Pt / 5% Rh | ~600 g/m² areal weight | 76 µm | Medium pressure, 3-7 barg |
| Pt-Rh-Pd (ternary) | Pt, Rh, plus a palladium fraction | Varies by plant design | Varies | Cost-reduction variant of the binary alloys |
Higher pressure has a cost: selectivity to NO falls from up to 97% at low pressure to 90% at ultra-high pressure, and platinum loss climbs from about 50 milligrams per tonne of nitric acid at atmospheric pressure to 250-400 milligrams per tonne at high pressure, per a peer-reviewed thermal-hydraulic study (PMC10756977). About half of that lost platinum is recaptured on a downstream palladium catchment gauze.
Where to Buy Platinum Mesh and Supplier Types#
Platinum mesh is sold by three supplier categories, each pricing against the live platinum value plus its own fabrication premium. Scientific-supply catalogs such as Goodfellow and Sigma-Aldrich list pure platinum gauze by mesh count and wire diameter, while catalytic-gauze packs are engineered directly by refiner-fabricators to each plant's pressure regime.
- Refiner-fabricators: custom ammonia-oxidation gauze packs, engineered to the pressure specifications above.
- Scientific-instrument suppliers: small, standardized mesh and gauze electrodes by mesh count and wire diameter.
- Specialty metal distributors: standard-purity platinum wire mesh for general fabrication orders.
Where Platinum Mesh Content Stops: Jewelry Retail and Converter Repair#
This page covers platinum mesh as an industrial and laboratory material, not ring-shopping guidance or converter-repair advice. Platinum jewelry uses cast or wrought alloy stock, not a woven mesh, so ring buying sits on this site's jewelry pages. Likewise, a used catalytic converter carries a washcoated PGM layer, not a fabricated gauze, so converter-scrap valuation is a separate topic from the products here.
Other Platinum Product Forms#
Platinum is also sold as several sibling wrought forms, each suited to a different need.
- Platinum wire: the drawn feedstock mesh is woven or knitted from.
- Platinum foil: a solid, continuous sheet rather than an open mesh.
- Platinum gauze: the dedicated ammonia-oxidation catalyst pack.
- Platinum electrodes: fabricated assemblies in mesh, wire and disk formats.
- Platinum crucibles: deep-drawn vessels for fire assay and glass handling.
Platinum Price and Market#
Platinum's spot price and supply-demand balance live on their own pages rather than here: see the live spot price for the current quote, and the platinum market page for mine supply and above-ground stocks.
Frequently Asked Questions#
What is a platinum gauze? A woven or knitted screen of fine platinum or platinum-rhodium wire, most commonly the 90Pt/10Rh or PtRh5 alloy used as the ammonia-oxidation catalyst in nitric acid production.
What is platinum wire used for? Thermocouples, resistance thermometers, laboratory electrodes and, woven or knitted, the gauze and mesh products covered on this page.
How expensive is platinum wire? Its price is the live platinum spot value for its weight, plus a fabrication premium varying with diameter, purity grade and order quantity; no fixed premium figure is published here.
How much does a platinum electrode cost? The same formula as any fabricated platinum product: live metal value for its weight, plus a fabrication premium set by the supplier for that electrode's design and quantity.
Where do we get platinum wire? From refiner-fabricators that draw it directly from refined platinum stock, from scientific-instrument suppliers selling standard laboratory diameters, or from specialty metal distributors.
What is a platinum electrode used for? Carrying current in electrolysis, electroplating and general electrochemistry, chosen because platinum resists oxidation and chemical attack from most electrolytes better than almost any other conductor.