Rhodium: Characteristics
The best catalyst for taming nitrogen oxides
What this tab covers The supply and physical characteristics of the commodity. Supply: current production, inventories and stocks, capacity utilisation, geographic and producer concentration, how fast supply responds to price, the project pipeline and capital spending, and logistics and export flows. Material: the physical and chemical properties that set its grade, price and end uses (for example purity and conductivity for metals, API gravity, sulfur and energy content for fuels, moisture, protein and fibre quality for crops).Supply volume characteristics
| Characteristic | Figure | What it means | Source |
|---|---|---|---|
| Current production volume | 701 koz (about 22 t) mine supply in 2025; 566 koz from South Africa | Russia supplied 68 koz, Zimbabwe 45 koz and North America 15 koz. Autocatalyst recycling added 312 koz. USGS does not report rhodium output separately. | Johnson Matthey PGM Market Report 2026 |
| Inventory and stock levels | not published; market deficit of about 50 koz in 2025 | There is no exchange or ETF stock of note. South African refiners released work-in-progress stocks in 2024 and 2025, which added to supply. Users hold working stocks of a few months (indicative). | Johnson Matthey 2026 |
| Capacity utilisation | not published | Output is set by how much PGM ore is mined and refined. Rationalisation and closures in South Africa and North America cut 2025 supply. | Johnson Matthey 2026 |
| Geographic and producer concentration | South Africa 83.0%; top-3 (South Africa, Russia, Zimbabwe) 98.3%; HHI 7,004 | Among the most concentrated of all commodities. In 2013 Anglo American Platinum (now Valterra) held 41.6% and Implats 24.9% of rhodium supply. | World Mining Data 2024; Tilton and Guzman 2016 |
| Supply elasticity | extremely low: about 95% companion metal of platinum | Rhodium is a small share of ounces in each tonne of ore. Even a fourfold price spike in 2020-21 barely raised supply. | Nassar et al. 2015; USGS prices |
| Project pipeline and CapEx | little new supply; UG2-rich and Platreef projects add small amounts | UG2 reef ore is relatively rich in rhodium, so new UG2 output helps most. Recycled rhodium from automotive scrap is expected to reach a four-year high in 2026. | Johnson Matthey 2026 |
| Logistics and export flows | no separate Comtrade code in these sources; US imported about 14,000 kg in 2025 | Refined rhodium sponge moves by air from South African refineries to catalyst makers in Europe, the US, Japan and China. The chokepoint is South African refining and power supply. | USGS MCS 2026 |
Material characteristics Metal / hard commodity
Rhodium is the best catalyst for reducing nitrogen oxides to nitrogen in petrol-car exhausts, which is why autocatalysts take about 85% of demand. It is also very hard, highly reflective and resistant to corrosion, so it is used as a bright, tough plating on jewellery and mirrors, and in glass-fibre bushings and chemical catalysts.
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Purity | commercial sponge or powder at least 99.9% Rh | Catalyst salts need high purity | Johnson Matthey (indicative) |
| NOx reduction activity | reduces NOx to N2 in three-way catalysts | No good substitute in petrol exhausts | Johnson Matthey (indicative) |
| Melting point | 1,964 C | Glass-fibre bushings and thermocouples (Pt-Rh) | CRC Handbook |
| Hardness | much harder than Pt; electroplated rhodium several hundred HV | Scratch-resistant plating on white gold and silver | Metals handbooks (indicative) |
| Reflectivity | about 80% of visible light | Mirrors, optical coatings | CRC Handbook (indicative) |
| Corrosion resistance | insoluble in most acids, including aqua regia in bulk form | Durable coatings and lab ware | CRC Handbook |
| Density | 12.41 g/cm3 | Assay and value checks | CRC Handbook |