Manganese dioxide
MnO2 · MANGANESE(IV) OXIDE · dioxomanganese · PYROLUSITE · ACTIVATED MANGANESE DIOXIDE · oxidizing agent · Manganese oxide (MnO2) · MANGANESE (IV) DIOXIDE
Identifiers & Physical Properties
| CAS No. | 1313-13-9 |
|---|---|
| Molecular formula | MnO2 |
| Average molar mass | 86.937 g/mol |
| Monoisotopic mass | 86.92787434 g/mol |
| SMILES | [O]=[Mn]=[O] |
| InChIKey | NUJOXMJBOLGQSY-UHFFFAOYSA-N |
| PubChem CID | 14801 |
| ChEBI | CHEBI:136511 |
| EC No. | 215-202-6 |
| DTXSID | DTXSID501314019 |
Chemical & Physical Properties
| Topological polar surface area | 34.1 |
|---|---|
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 2 |
| Rotatable bonds | 0 |
| Heavy atoms | 3 |
| Formal charge | 0 |
| Complexity | 18.3 |
| Chemical classes | Metals -> Manganese Compounds, Inorganic |
| SpringerMaterials Properties | dielectric constant |
| Density | 5.0 g/cm³5.08 @25 °C5.02 |
| Solubility | Solubility in water: none<0.001g/l insoluble |
| Decomposition | 535 °C |
| Physical Description | Dry PowderLarge CrystalsCBIOther SolidWet SolidNatural form is steel-gray when in lumps and black when powderedThe artificial precipitate in a brownish-black solidBoth usually have some manganese oxide and water[Merck Index] Brown odorless powder[Alfa Aesar MSDS]BLACK-TO-BROWN POWDER. |
| Melting point | 535 °C (dec.) (lit.) |
| Bulk density | 600-800kg/m3 |
| Vapor pressure | 0-0Pa at 25℃ |
| Storage conditions | Store below +30°C. |
| Physical state | powder |
| Color | gray |
| Specific gravity | 5.026 |
| Specific heat capacity | Cp(crystal): 0.62 J/(g·K), at 25℃ |
| Crystal Structure | Rutile type |
| crystal system | square |
| Merck | 14,5730 |
| Space group | P42/mnm |
| Lattice constant | a/nm |
| GHS pictogram | GHS07,GHS08 |
| Signal word | Warning |
| GHS hazard statements | H302+H332-H373 |
| GHS precautionary statements | P260-P264-P270-P301+P312-P304+P340+P312-P314 |
| Target organs | Brain |
| Hazard symbols | Xn |
| Risk statements (R) | 20/22 |
| Safety statements (S) | 25 |
| UN transport number | 3137 |
| Water hazard class (WGK) | 1 |
| RTECS number | OP0350000 |
| TSCA inventory status | TSCA listed |
| Customs code | 2820 10 00 |
| Packing group | III |
| Storage class | 13 - Non Combustible Solids |
| Hazard class | Acute Tox. 4 InhalationAcute Tox. 4 OralSTOT RE 2 Inhalation |
| Toxicity | LD50 orally in rats: >40 mmole/kg (Holbrook) |
| REACH registrations | Active |
Safety & Regulations
| GHS classification | WarningH302: Harmful if swallowed [Warning Acute toxicity, oral]P261, P264, P270, P271, P301+P317, P304+P340, P317, P330, and P501 (click each P-code to see the statement)This chemical does not meet GHS hazard criteria for 0.8% (11 of 1416) of reports.H302+H332 (12.5%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oralacute toxicity, inhalation] |
|---|---|
| Regulatory information | Chemical: Manganese oxide (MnO2)Manganese oxide (MnO2) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Manganese oxide (MnO2) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)Status: Active Update: 27-02-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15404Manganese (IV) oxide: HSNO Approval: HSR003741 Approved with controls |
| Other safety information | IMAP assessments - Manganese oxides: Human health tier II assessment |
| Fire hazards | Not combustible but enhances combustion of other substances. |
| Hazards summary | Inhalation of dust may cause diseases of the lungs (bronchitis and pneumonia) and CNS (manganism)[ICSC] A strong oxidizer[Merck Index] Harmful by ingestion, inhalationMay cause irritation[Alfa Aesar MSDS] See Manganese and linked occupational diseases. |
| EC classification | Symbol: XnR: 20/22S: (2)-25 |
| Chemical Dangers | Decomposes above 553 °C . This produces manganese(III)oxide and oxygen, which increases fire hazard. The substance is a strong oxidant. It reacts violently with combustible and reducing materials. This generates fire and explosion hazard. Reacts with aluminium on heating. |
| Hazard Classes and Categories | Acute Tox. 4 (97.6%)Not ClassifiedSpecific target organ toxicity (repeated exposure) - category 1Specific target organ toxicity - Single exposure - Category 1 (respiratory system)Acute Tox. 4 * |
| Fire fighting | In case of fire in the surroundings, use appropriate extinguishing media. |
| First aid measures | Fresh air, rest. Refer for medical attention.Rinse and then wash skin with water and soap.First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.Rinse mouth. Refer for medical attention . |
| Safe storage | Separated from combustible substances and reducing agents. |
| Exposure control and personal protection | 0.2 [mg/m3], as Mn (inhalable fraction), 0.02 mg/m3, as Mn (respirable fraction)[German Research Foundation (DFG)] |
| Spillage disposal | Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Do NOT absorb in saw-dust or other combustible absorbents. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. |
| Eye Prevention | Wear safety goggles or eye protection in combination with breathing protection if powder. |
| Fire Prevention | NO contact with combustible substances. |
| Inhalation Risk | Evaporation at 20 °C is negligiblea harmful concentration of airborne particles can, however, be reached quickly when dispersed. |
| Skin Prevention | Protective gloves. |
| Minimum Risk Level | Chronic Inhalation: 0.0003 mg/m3 (L134) |
| Exposure Prevention | PREVENT DISPERSION OF DUST! AVOID EXPOSURE OF (PREGNANT) WOMEN! |
| Ingestion Prevention | Do not eat, drink, or smoke during work. |
| Treatment | EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration. |
| Health effects | Manganese mainly affects the nervous system and may cause behavioral changes and other nervous system effects, which include movements that may become slow and clumsy. This combination of symptoms when sufficiently severe is referred to as “manganism”. (L228) |
| Adverse effects | Neurotoxin - Parkinsonism |
| Exposure routes | The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.Oral (L228)inhalation (L228) |
| Toxicity summary | Manganese is a cellular toxicant that can impair transport systems, enzyme activities, and receptor functions. It primarily targets the central nervous system, particularily the globus pallidus of the basal ganglia. It is believed that the manganese ion, Mn(II), enhances the autoxidation or turnover of various intracellular catecholamines, leading to increased production of free radicals, reactive oxygen species, and other cytotoxic metabolites, along with a depletion of cellular antioxidant defense mechanisms, leading to oxidative damage and selective destruction of dopaminergic neurons. In addition to dopamine, manganese is thought to perturbations other neurotransmitters, such as GABA and glutamate. In order to produce oxidative damage, manganese must first overwhelm the antioxidant enzyme manganese superoxide dismutase. The neurotoxicity of Mn(II) has also been linked to its ability to substitute for Ca(II) under physiological conditions. It can enter mitochondria via the calcium uniporter and inhibit mitochondrial oxidative phosphorylation. It may also inhibit the efflux of Ca(II), which can result in a loss of mitochondrial membrane integrity. Mn(II) has been shown to inhibit mitochondrial aconitase activity to a significant level, altering amino acid metabolism and cellular iron homeostasis. (L228) |
| Signs and Symptoms | Cough.Abdominal pain. Nausea.Manganese mainly affects the nervous system and may cause behavioral changes and other nervous system effects, which include movements that may become slow and clumsy. This combination of symptoms when sufficiently severe is referred to as “manganism”. (L228) |
| ICSC Environmental Data | This substance may be hazardous to the environment. Special attention should be given to aquatic organisms. |
| Carcinogen Classification | No indication of carcinogenicity to humans (not listed by IARC). |
| Toxicity Data | LD50: >3478 mg/kg (Oral, Rat) (L326) |
| Water hazard class (WGK) | 1 |
| TSCA inventory status | TSCA listed |
| RTECS number | OP0350000 |
| UN transport number | 3137 |
| Customs code | 2820 10 00 |
| Toxicity | LD50 orally in rats: >40 mmole/kg (Holbrook) |
| Risk statements (R) | 20/22 |
| Signal word | Warning |
| GHS pictogram | GHS07,GHS08 |
| Hazard symbols | Xn |
| Safety statements (S) | 25 |
| Storage class | 13 - Non Combustible Solids |
| Packing group | III |
| Target organs | Brain |
| GHS hazard statements | H302+H332-H373 |
| REACH registrations | Active |
| Hazard class | Acute Tox. 4 InhalationAcute Tox. 4 OralSTOT RE 2 Inhalation |
| GHS precautionary statements | P260-P264-P270-P301+P312-P304+P340+P312-P314 |
Applications & Uses
Description
Manganese dioxide, mainly used as a depolarizer in dry cell batteries, is the most important non-metallic form of manganese. In either traditional alkaline and rechargeable battery cells, Manganese dioxide takes in electrons through a redox reaction, becoming Manganese III oxide. It also has applications in lithium-ion technologies. It is also the primary precursor to ferromanganese, an alloy of iron used for its lower melting point and low cost. It is black in appearance and used to color glass and ceramics, as well as for cave art and possibly body paint in prehistorical eras. Further uses include the purification of drinking water, and production of pure oxygen and chlorine.
Description
Manganese dioxide is a black crystalline solid. Molecular weight= 86.94; Freezing/Melting point=(decomposes)=53℃. Hazard Identification (based on NFPA-704 M Rating System): Health 3, Flammability 0, Reactivity×(Oxidizer). Insoluble in water.
Uses
As an oxidizing agent, source of metallic manganese, decolorizing glass, painting porcelain, as an analytical reagentManganese(IV) oxide is used as an oxidizing agent in organic synthesis such as oxidation of allylic/benzylic alcohols, as a textile dye, as a reducing agent, and as a component of dry cell batteries such as zinc-carbon battery and alkaline battery. It is also used in making pigments for glasses and ceramics, and drier for paints. Further it is used in the manufacture of manganese steel and several manganese derivatives including potassium permanganate, a powerful versatile oxidant. Catalytic hydration of nitriles to amides by flowing through manganese dioxide has been reported. Manganese dioxide supported on inorganic oxide can be used for oxidation of methylamine through CWAO (Catalytic Wet Air Oxidation). It has high potential as highly efficient and robust material for water oxidation reaction (WORs).
Uses
Manganese(IV) oxide is the most important ore of manganese from which the metal is mostly manufactured. The oxide occurs in nature as the mineral pyrolusite as heavy gray lumps, or black when powdered. The mineral is used to produce manganese metal, most manganese salts, and also manganese steel and other alloys. The metallurgical applications of manganese(IV) oxide mainly involve making ferromanganese and special manganese alloys. Another important application of manganese(IV) oxide is in manufacturing dry-cell batteries and alkaline cells. The oxide also is a colorant in brick, tile, porcelain and glass; a drier for paints and varnishes; a 552 MANGANESE(IV) OXIDEpreparation for printing and dyeing textiles; a curing agent for polysulfide rubbers; an adsorbent for hydrogen sulfide and sulfur dioxide; an oxidizing agent in many organic syntheses such as quinone and hydroquinone; and a catalyst in laboratory preparation of oxygen from potassium chlorate. Manganese(IV) oxide also is used to make welding rods and fluxes, and ceramic magnets (ferrites); and is an additive to fertilizers.
Uses
The mineral is the source of manganese and all its Compounds; largely used in manufacture of manganese steel; oxidizer; in alkaline batteries (dry cells); for making amethyst glass, decolorizing glass; painting on porcelain, faience and majolica. The ppt is used in electrotechnics, pigments, browning gun barrels, drier for paints and varnishes, printing and dyeing textiles.
General Description
Manganese(IV) oxide (MnO2) is an eco-friendly chemical having a high theoretical specific capacitance.
Preparation & Synthesis
Preparation
Pure manganese(IV) oxide (precipitate form) may be prepared by reducing permanganate ion with a manganous salt: 2KMnO4 + 3MnSO4 + 2H2O → 5MnO2 + K2SO4 + 2H2SO4 Manganese(IV) oxide can also be precipitated by oxidation of a manganese(II) salt using an oxidizing agent such as hypochlorite or peroxydisulphate: Mn2+ + S2O82– + 2H2O → MnO2 + 2SO42– + 4H+ Manganese(IV) oxide may also be made by thermal decomposition of manganese(II) nitrate; or from roasting manganese(II) carbonate in air: Mn(NO3)2 → MnO2 + 2NO2 MnCO3 + ½ O2 → MnO2 + CO2 A highly active gamma-MnO2 can be produced by treating manganese(III) oxide with hot sulfuric acid: Mn2O3 + H2SO4 → MnO2 + MnSO4 + H2O Mn2O3 is derived from pyrolusite by heating the mineral at 600–800°C or reducing with powdered coal at 300°C.