12036-35-0 Usage
Description
Rhodium oxide, with the chemical formula Rh2O3, is a gray crystalline solid or amorphous powder that possesses a corundum-type structure. It has a density of 8.20 g/cm3 and decomposes at temperatures around 1,100 to 1,150°C. Rhodium oxide is insoluble in water, acids, and aqua regia. There are also hydrated forms of rhodium oxide, such as the pentahydrate (Rh2O3·5H2O) which is a yellow precipitate, soluble in acids, and partially dissolves in hot water, and the trihydrate (Rh2O3·3H2O) which is a black precipitate and insoluble in acids.
Uses
Used in Metal and Salt Production:
Rhodium oxide is used as a precursor for the production of rhodium metal and its various salts, which are essential for various industrial applications.
Used in Automotive Industry:
Rhodium oxide is used as a catalyst in the catalytic converters of automobiles, helping to reduce harmful emissions and improve fuel efficiency.
Used in Chemical Production:
Rhodium oxide is used as an industrial catalyst in the manufacturing of chemical intermediates, such as oxo-alcohols, and in the production of nitric acid and ethanoic (acetic) acid.
Used in Electronics Industry:
Rhodium oxide is an area of interest for researchers in the development of new capacitor electrode materials, as well as for manufacturers of dynamic random access memory (DRAMs) and non-volatile random access memories (FeRAMs).
Physical properties:
Rhodium oxide is a yellow powder in its hydrated form, with a density of 8.20 g/cm3. It decomposes at temperatures around 1,100 to 1,150°C and is insoluble in water, acids, and aqua regia. The pentahydrate form (Rh2O3·5H2O) is soluble in acids and partially dissolves in hot water, while the trihydrate form (Rh2O3·3H2O) is insoluble in acids.
Preparation
Rhodium sesquioxide is obtained by heating rhodium metal to red heat in air.
4Rh + 3O2 → 2Rh2O3
Alternatively, Rh2O3 may be prepared by igniting rhodium nitrate, Rh(NO3)3.
Treating the sesquioxide with alkali first forms a yellow precipitate of pentahydrate, Rh2O3?5H2O, soluble in acid and excess alkali. In excess alkali a black precipitate of trihydrate, Rh2O3?3H2O is obtained. The trihydrate is insoluble in acids.
Production Methods
Rhodium(III) oxide, Rh2O3, can be prepared by heating the finely divided metal or its nitrate in air or O2. The rhodium(IV) oxide is also known. Rhodium trihydroxide may be precipitated as a yellow compound by adding the stoichiometric amount of KOH to a solution of RhCl3. The hydroxide is soluble in acids and excess base. When the freshly precipitated Rh(OH)3 is dissolved in HCl at a controlled pH, a yellow solution is first obtained in which the aquochloro complex of Rh behaves as a cation.
Flammability and Explosibility
Notclassified
Check Digit Verification of cas no
The CAS Registry Mumber 12036-35-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,2,0,3 and 6 respectively; the second part has 2 digits, 3 and 5 respectively.
Calculate Digit Verification of CAS Registry Number 12036-35:
(7*1)+(6*2)+(5*0)+(4*3)+(3*6)+(2*3)+(1*5)=60
60 % 10 = 0
So 12036-35-0 is a valid CAS Registry Number.
InChI:InChI=1/3O.2Rh/rO3Rh2/c1-4-3-5-2
12036-35-0Relevant articles and documents
Preparation of intermetallic phases of noble metals and tin by thermolysis of metal-organic coordination polymers
Rehbein, Marcus,Fischer, R.Dieter,Epple, Matthias
, p. 143 - 149 (2002)
Intermetallic phases of noble metals (Ru, Rh, Pd, Os, Ir, Pt and Au) were prepared by controlled thermolysis of coordination polymers on the basis of cyanometallates and trimethyltin units (super-prussian blue derivatives). The thermal reaction was carried out under different atmospheres: oxidizing, inert and reducing, upto 1000 °C. Under oxidizing conditions, intimate mixtures of oxides (SnO2 with RuO2, Rh2O3, IrO2, Pt3O4, respectively) were obtained that could be reduced in a second step to the pure noble metals and intermetallic phases incorporating tin (Ru3Sn7, RhSn2, IrSn4, Ir5Sn7, IrSn2, PdSn2, Pd20Sn13, Pd3Sn2, PtSn, PtSn4, Au5Sn, AuSn were all detected). Under reducing conditions, mixtures of metals and intermetallic phases were obtained that could subsequently be oxidized by further thermal treatment to noble metals on SnO2. This offers a new synthetic pathway to such intermetallics and to noble metals on SnO2 supports.
