Name | Rhodium(III) oxide hydrate |
Synonyms | Rhodium oxide rhodium oxide oxygen(-2) anion RHODIUM(+3)OXIDE dirhodium trioxide Rhodium(III) oxide Dirhodium trioxide RHODIUM(III) OXIDE rhodium(+3) cation RHODIUM SESQUIOXIDE RHODIUM(III) OXIDE, oxo-(oxorhodiooxy)rhodium Rhodium(III) oxide hydrate RHODIUM(III) OXIDE ANHYDROUS Rhodiumoxideanhydrousgraypowder |
CAS | 12036-35-0 |
EINECS | 234-846-9 |
InChI | InChI=1/3O.2Rh/rO3Rh2/c1-4-3-5-2 |
InChIKey | XBBXDTCPEWHXKL-UHFFFAOYSA-N |
Molecular Formula | H2ORh |
Molar Mass | 120.92 |
Density | 8.2g/mLat 25°C(lit.) |
Melting Point | 1100°C (dec.) |
Water Solubility | Insoluble in water, acetone, conc. Hydrochloric acid, Nitric acid, Aqua regia. |
Appearance | Dark gray to black powder |
Specific Gravity | 8.2 |
Color | Yellow |
Exposure Limit | ACGIH: TWA 1 mg/m3NIOSH: IDLH 100 mg/m3; TWA 0.1 mg/m3 |
Storage Condition | under inert gas (nitrogen or Argon) at 2-8°C |
Sensitive | Hygroscopic |
MDL | MFCD00011205 |
Risk Codes | R36/38 - Irritating to eyes and skin. R8 - Contact with combustible material may cause fire |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. S37/39 - Wear suitable gloves and eye/face protection S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S17 - Keep away from combustible material. |
UN IDs | 3288 |
WGK Germany | 3 |
TSCA | Yes |
HS Code | 28259085 |
Hazard Class | 6.1(b) |
Packing Group | III |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
Overview | Rhodium oxide is rhodium trioxide. Chemical formula Rh2O3. Molecular weight 253.81. Gray crystal or amorphous powder. Relative density 8.20. Insoluble in water, acid, aqua regia and alkali. It is decomposed into metal rhodium and oxygen at 1100~1500 ℃. It can be reduced to rhodium by reducing agents such as hydrogen and sulfur dioxide. Its pentahydrate is lemon yellow powder, insoluble in water, soluble in a variety of acids, fresh precipitate soluble in concentrated alkali, heat loses water and decomposes to release oxygen. The decomposition product is insoluble black rhodium tetroxide. (2016-03-03) |
preparation | is obtained by heating rhodium (600~1000 ℃) in air or oxygen, or dehydration of its hydrate, or by thermal decomposition of nitrate. |
use | rhodium oxide can be used to make various rhodium salts, catalysts, special alloys and electroplating. |
application | 1. it can be used to make ceramics. ceramics made by adding rhodium oxide have superior thermal shock resistance and can be used in high-temperature parts, especially in parts where hot and cold alternate frequently. It can also improve its wear resistance. It greatly reduces the production energy consumption of wear-resistant ceramics and contributes to energy conservation and emission reduction. 2. The supercapacitor made with rhodium oxide is made of nitrogen-coated waste PVC-based composite electrode material, which has the advantages of large specific surface area, high conductivity efficiency, and simple preparation process. The doped nano-chromium carbonate and ammonia bicarbonate promote activated carbon The formation of pores and surface activity can enhance the penetration of electrolyte ions and improve conductivity, the production process also has the advantages of simple process, short production cycle, simple and easy to obtain raw materials, and wide application fields. |
production method | 1. rhodium powder is mixed with sodium chloride, treated with chlorine at a high temperature of 600~700 ℃, and dissolved with warm water after cooling to prepare purple-red Na3RhCl6 solution. insoluble residue can be repeatedly treated with NaCl. Add sodium hydroxide aqueous solution to the solution but do not overdo it. The reaction will generate yellowish brown Rh(OH)3 precipitate. Attention should be paid to the slow reaction. The precipitate is separated, burned at a temperature of about 1000 ℃, and Rh2O3 can be obtained after about 1 hour. 2.β-Rh2O3 can be obtained by heating rhodium powder in air and at a temperature of 900 ℃ for 60h, or β-Rh2O3 can also be obtained by heating sponge rhodium in air and at a temperature of 980 ℃ for 100h. In addition, pure α-Rh2O3 can be obtained by heating Rh(NO3)3 · 6H2O for 50h in air and at a temperature of 730 ℃. |