Platinum
PT · PLATINUM ON CARBON · PLATINUM BLACK · PLATINUM SPONGE · Platin · PLATINIUM · PLATINUM CARBON · PLATINUM CATALYST
Identifiers & Physical Properties
| CAS No. | 7440-06-4 |
|---|---|
| Molecular formula | Pt |
| Average molar mass | 195.08 g/mol |
| Monoisotopic mass | 194.964794 g/mol |
| SMILES | [Pt] |
| InChIKey | BASFCYQUMIYNBI-UHFFFAOYSA-N |
| PubChem CID | 23939 |
| ChEBI | CHEBI:33364 |
| EC No. | 231-116-1 |
| DTXSID | DTXSID9064681 |
Chemical & Physical Properties
| Topological polar surface area | 0 |
|---|---|
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 0 |
| Rotatable bonds | 0 |
| Heavy atoms | 1 |
| Formal charge | 0 |
| Complexity | 0 |
| LogP (partition coefficient) | 0.03 |
| Density | 21.45 (NIOSH, 2024) - Denser than waterwill sink21.447 (calc)21.45 g/cm³21.45 @25 °C21.45 g/cm3 (lit.) |
| Color/Form | Silver-gray, lustrous, malleable and ductile metalface-centered cubic structure. Also prepd in the form of a black powder (platinum black) and as spongy masses (platinum sponge). |
| Solubility | Insoluble (NIOSH, 2024)Soluble in aqua regia. Insoluble in mineral and organic acids.Solubility in water: insolubleSoluble in hot aqua regia. |
| Corrosivity | Does not corrode or tarnish |
| Boiling point | 6921 °F at 760 mmHg (NIOSH, 2024)3825 °C3827 °C3825 °C @760 [mm Hg]3827 °C (lit.) |
| Melting point | 3222 °F (NIOSH, 2024)1772 °C.1768.4 °C1768.3 °C1769 °C1772 °C (lit.) |
| Vapor pressure | 0 mmHg (approx) (NIOSH, 2024)0.0187 Pa @ melting pointdepends upon the specific compound |
| Physical Description | Silvery, whitish-gray, malleable, ductile metal. Mp: 1772 °Cbp: 2187 °C. Density: 21.45 g cm-3 at room conditions (very dense). Also shipped as a finely divided powder (platinum black), as a sponge, and as particles deposited on a supporting material such as alumina. Has strong catalytic activity in these formsfinely divided platinum can be dangerous to handle in the vicinity of other chemicals on this account. Used platinum catalysts are particularly dangerous and can be explosive.Appearance and odor vary depending upon the specific soluble platinum salt. [NIOSH]Silver-grey lustrous solidAlso available as black powder (platinum black) and spongy solid (platinum sponge)[Merck Index]BLACK POWDER.Silvery, whitish-gray, malleable, ductile metal. |
| Other Experimental Properties | Sp heat: 0.0314 cal/g at 0 °C. Electrical resistivity: (20 deg) 10.6 uohm-cm./Platinum/ occurs naturally mainly as the isotopes (194)Pt, (195)Pt, and (196)Pt.Heated platinum adsorbs large amounts of hydrogenit is a strong complexing agent. |
| Refractive index | n20/D 1.347 |
| Flash point | 3825°C |
| Storage conditions | 2-8°C |
| Physical state | wire |
| Color | White |
| Specific gravity | 21.45 |
| pH | 0.5 (20°C in H2O) |
| Viscosity | 2500-4500mPa.s (Analysis carried out at 20°C with 20mm 4 degree cone/plate40 s-1) |
| Resistivity | 10.6 μΩ-cm, 20°C |
| Electrical Conductivity | 9.4× 106S/m |
| Thermal conductivity | 71 W/(m·K) |
| Specific heat capacity | Cp(crystal): 0.13 J/(g·K)Cp(gas): 0.13 J/(g·K), at 25℃ |
| Merck | 14,7529 |
| Dielectric constant | 6.5(Ambient) |
| Exposure limits | ACGIH TLV-TWA:0.002 mg/m3 — Soluble salts,as PtOSHA PEL-TWA:0.002 mg/m3NIOSH REL-TWA:1 mg/m3 |
| Stability | Stable. Platinum black is highly flammable. |
| Cosmetics Ingredients Functions | SKIN CONDITIONINGSKIN CONDITIONING - MISCELLANEOUSDEODORANTANTIMICROBIALABRASIVEANTIOXIDANT |
| InChI | 1S/Pt |
| InChIKey | BASFCYQUMIYNBI-UHFFFAOYSA-N |
| SMILES | [Pt] |
| CAS DataBase Reference | 7440-06-4(CAS DataBase Reference) |
| NCI Dictionary of Cancer Terms | platinum |
| FDA UNII | 49DFR088MY |
| NIST Chemistry Reference | Platinum(7440-06-4) |
| EPA Substance Registry System | Platinum (7440-06-4) |
| UNSPSC Code | 41116107 |
| NACRES | NA.24 |
| GHS pictogram | GHS02 |
| Signal word | Danger |
| GHS hazard statements | H228 |
| GHS precautionary statements | P210-P240-P241-P280-P370+P378 |
| Hazard symbols | F,Xi,Xn,N |
| Risk statements (R) | 11-37-20-36/37/38-36/37-40-42/43-22-50/53 |
| Safety statements (S) | 36-7/9-33-16-38-22-26-14-36/37/39-27-24/25-36/37-45-23-61-60 |
| UN transport number | UN 3264 8/PG 3 |
| Occupational exposure band (OEB) | C |
| Occupational exposure limit (OEL) | TWA: 1 mg/m3 |
| Water hazard class (WGK) | 3 |
| RTECS number | TP2160000 |
| TSCA inventory status | TSCA listed |
| Hazard class | 4.1 |
| Packing group | III |
| Customs code | 28439000 |
| Storage class | 13 - Non Combustible Solids |
| Hazardous substances data | 7440-06-4(Hazardous Substances Data) |
| Immediately dangerous to life or health concentration | 4 mg Pt/m3 |
| REACH registrations | Active |
| Limited quantities | 5.0 Kg (11 lbs) (solid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L) |
Safety & Regulations
| GHS classification | This chemical does not meet GHS hazard criteria for 81.3% (410 of 504) of all reports.DangerH228 (10.7%): Flammable solid [Danger Flammable solids]P210, P240, P241, P280, and P370+P378 (click each P-code to see the statement)Aggregated GHS information provided per 504 reports by companies from 13 notifications to the ECHA C&L Inventory.Reported as not meeting GHS hazard criteria per 410 of 504 reports by companies.There are 11 notifications provided by 94 of 504 reports by companies with hazard statement code(s).Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. |
|---|---|
| Regulatory information | Chemical: PlatinumStatus: Active Update: 28-09-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/19458Platinum: Does not have an individual approval but may be used under an appropriate group standardThe New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.) |
| Other safety information | IMAP assessments - Platinum: Human health tier I assessmentIMAP assessments - Platinum: Environment tier I assessment |
| DOT label | Flammable Solid |
| Fire hazards | Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:May react violently or explosively on contact with water. Some are transported in flammable liquids. May be ignited by friction, heat, sparks or flames. Some of these materials will burn with intense heat. Dusts or fumes may form explosive mixtures in air. Containers may explode when heated. May re-ignite after fire is extinguished. (ERG, 2024)See Chemical dangers |
| Fire potential | Flammable in a state of powder. |
| Health hazards | Excerpt from NIOSH Pocket Guide for Platinum:Exposure Routes: Inhalation, ingestion, skin and/or eye contactSymptoms: Irritation skin, respiratory systemdermatitisTarget Organs: Eyes, skin, respiratory system (NIOSH, 2024) |
| Hazards summary | The allergenic compounds appear to be limited to the coordination complexes containing halogen ligands as leaving groups with the most potent examples being hexa- and tetrachloroplatinates. [Nordberg, p. 1138] Occupational asthma reported in platinum refinery[Malo] Allergic contact dermatitis in electronics workers[Marks] Platinum salts can cause immunologic, occupational contact urticaria[Kanerva, p. 219] There is evidence from pharmacologic use that platinum is nephrotoxic. [Rosenstock, p. 572]A skin, eye, and respiratory tract irritant[Merck Index] Catalytic material that is fire and explosion hazard on contact with many organic and inorganic substancesAn eye and respiratory tract irritant(powdered form) [ICSC] Platinum oxides and soluble platinum salts are sensitizers. Platinum is nontoxic in the metallic state, except possibly for the fine powdered form. [Sullivan, p. 911, 913] Platinum dust is inert and nonallergenic[Nordberg, p. 1136] Tram drivers in Rome were exposed to Pt, Rh and Pd from catalytic converters at levels about 10 times lower than those known to cause adverse effects in workers. [PMID 18849761] In a study of platinum nanoparticles, platinum ions were not released into the culture media suggesting minimal cellular influence[PMID 21804981] See Platinum, soluble salts. |
| Reactive group | Metals, Less Reactive |
| Reactivity Alerts | Known Catalytic Activity |
| Reactivity Profile | Massive platinum (lump, ingot, etc.) is generally inert. Dissolves readily in aqua regia (mixture of concentrated hydrochloride and concentrated nitric acids). Reacts rapidly with molten alkali metal oxides and peroxides. Reacts with F2 and Cl2 at red heat. Absorbs large volumes of hydrogen when hot. Catalyzes the exothermic oxidation of ammonia by air. Finely divided platinum is incompatible with aluminum, acetone, arsenic, ethane, hydrazine, hydrogen peroxide, lithium, phosphorus, selenium, tellurium and many fluorides. Explosion can occur upon contact with hydrogen peroxide. Platinum black, sponge and supported catalysts have strong catalytic activitycan be dangerous to handle in the vicinity of other chemicals on this account. Used platinum catalysts are particularly dangerous and can cause explosions. Ethanol or methanol can ignite on contact with a platinum-black catalyst. (Urben 1794). |
| Chemical Dangers | Platinium is a catalytic substance and may cause reaction in contact with many organic and inorganic substances, causing fire and explosion hazard. |
| Flammable Limits | Noncombustible Solid in bulk form, but finely divided powder can be dangerous to handle. |
| Fire fighting | Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:DO NOT USE WATER, FOAM OR CO2. Dousing metallic fires with water will generate hydrogen gas, an extremely dangerous explosion hazard, particularly if fire is in a confined environment (i.e., building, cargo hold, etc.). Use DRY sand, graphite powder, dry sodium chloride-based extinguishers, or class D extinguishers. Confining and smothering metal fires is preferable rather than applying water. If it can be done safely, move undamaged containers away from the area around the fire.FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: If impossible to extinguish, protect surroundings and allow fire to burn itself out. (ERG, 2024)In case of fire in the surroundings, use appropriate extinguishing media. |
| First aid measures | Fresh air, rest.Remove contaminated clothes. 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 . |
| First aid | Excerpt from NIOSH Pocket Guide for Platinum:Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.Skin: SOAP WASH - If this chemical contacts the skin, wash the contaminated skin with soap and water.Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)(General first aid procedures)Breathing: Respiratory supportSwallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. |
| Safe storage | Well closed. |
| Cleanup methods | Persons not wearing protective equipment and clothing should be restricted from areas of spills until cleanup has been completed. If soluble platinum salts or liquids containing soluble salts are spilled, the following steps should be taken: 1. Ventilate area of spill2. Collect spilled material in the most convenient and safe manner for reclamation or for disposal in a secured sanitary landfill. Liquids containing soluble platinum salts should be absorbed in vermiculite, dry sand, earth, or a similar material, /Soluble platinum salts/ |
| Nonfire spill response | Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024) |
| Disposal methods | SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices. |
| Spillage disposal | Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Then store and dispose of according to local regulations. |
| Preventive Measures | Adequate ventilation and protectors. Induce workers to wash constantly.Eating and smoking should not be permitted in areas where soluble platinum salts or liquids containing soluble platinum salts are handled, processed, or stored. Employees who handle soluble platinum salts or liquids containing soluble platinum salts should wash their hands thoroughly before eating, smoking, or using toilet facilities. /Soluble platinum salts/Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented. ... If the use of respirators is necessary, the only respirators permitted are those that have been approved by the Mine Safety and Health Admin (formerly Mining Enforcement & Safety Admin) or by the National Institute for Occupational Safety & Health. In addition to respirator selection, a complete respiratory protection program should be instituted which includes regular training, maintenance, inspection, cleaning, and evaluation. /Soluble platinum salts/Control can only be achieved by preventing the release of the soluble complex platinum salts to the atmosphere of the workshop. Good exhaust ventilation is necessary in platinum refineries. Chemical procedures which may generate these salts should be carried out in ventilated fume cupboards. Open centrifuges should not be used. Good personal hygiene is important. /Platinum compounds/For more Preventive Measures (Complete) data for PLATINUM (10 total), please visit the HSDB record page. |
| Isolation and Evacuation | Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.LARGE SPILL: Consider initial downwind evacuation for at least 50 meters (160 feet).FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directionsalso, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024) |
| Eye Prevention | Wear safety goggles. |
| Inhalation Risk | Evaporation at 20 °C is negligiblea nuisance-causing concentration of airborne particles can, however, be reached quickly , especially if powdered. |
| Target organs | Eyes, skin, respiratory system |
| Adverse effects | Nephrotoxin - The chemical is potentially toxic to the kidneys in the occupational setting.Skin Sensitizer - An agent that can induce an allergic reaction in the skin.Asthma - Reversible bronchoconstriction (narrowing of bronchioles) initiated by the inhalation of irritating or allergenic agents. |
| Exposure routes | The substance can be absorbed into the body by inhalation.inhalation, ingestion, skin and/or eye contact |
| Signs and Symptoms | Cough. Sore throat.Redness. Pain.irritation skin, respiratory systemdermatitis |
| Human Toxicity Excerpts | Platinum metal itself is not associated with any neurological diseases ... .Clinical signs & symptoms of platinum exposure & toxicity via inhalation & dermal routes are those of classic allergic reactions & include irritation of the eyes & nosecough, dyspnea, wheezing, & cyanosisskin sensitization& lymphocytosis.Effects on human sperm motility were investigated ... Fresh sperm were incubated for up to5 hr in the presence of strips of platinum or other metals. Motility after 2 and 5 hr was 60 and 30%, respectively, compared to 10 and 0% for copper, 40 and 7% for silver, and 90 and 65% for gold.Some workers may show ... allergic manifestations with involvement of the nasal mucosa, bronchi and skin. /Platinum cmpd/ |
| Non-Human Toxicity Excerpts | Platinum wire inserted into the uterus of rats was reported to reduce the implantation of fertilized ova. An 83% reduction in the number of implantation sites in the affected uterine horn, compared to the unoperated horn, was found in rats unilaterally implanted on day 3. ... No effect /was found/ on embryonic or fetal survival if platinum wire was inserted after implantation on day 6.... Normal fertility /was found/ in male rabbits with open tube gold/platinum devices inserted into the vas deferens. There was an initial decrease in sperm count and motility, but these parameters returned to normal after three weeks. At 117-426 days after insertion, 7 out of 9 animals were fertile in numerous matings. |
| Antidote and Emergency Treatment | Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poison A and B/Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/ |
| Occupational exposure band (OEB) | C |
| Occupational exposure limit (OEL) | TWA: 1 mg/m3 |
| Water hazard class (WGK) | 3 |
| Immediately dangerous to life or health concentration | 4 mg Pt/m3 |
| TSCA inventory status | TSCA listed |
| RTECS number | TP2160000 |
| UN transport number | UN 3264 8/PG 3 |
| Customs code | 28439000 |
| Risk statements (R) | 11-37-20-36/37/38-36/37-40-42/43-22-50/53 |
| Signal word | Danger |
| GHS pictogram | GHS02 |
| Hazard symbols | F,Xi,Xn,N |
| Safety statements (S) | 36-7/9-33-16-38-22-26-14-36/37/39-27-24/25-36/37-45-23-61-60 |
| Hazard class | 4.1 |
| Storage class | 13 - Non Combustible Solids |
| Packing group | III |
| GHS hazard statements | H228 |
| Limited quantities | 5.0 Kg (11 lbs) (solid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L) |
| REACH registrations | Active |
| GHS precautionary statements | P210-P240-P241-P280-P370+P378 |
| Hazardous substances data | 7440-06-4(Hazardous Substances Data) |
Applications & Uses
Uses
Jewelry; oxygen sensor in internal combustion engines; chemical and electrical industries; dentistry; windings of hightemperature furnaces; electroplating; photography; cancer chemotherapeutic agents
Uses
Catalysis:Platinum is found in the environment naturally and from anthropogenic sources. Platinum is primarily used in industry as a catalyst, predominately for the production of vehicle catalytic converters. Platinum is also used in the chemical, electrical, glass, dental, healthcare, pharmaceutical, petroleum, and jewelry fields. In addition to its catalytic properties, platinum, in combination with cobalt, has powerful magnetic properties.Platinum metal and its alloys have numerous applications. As a precious metal it is used extensively in jewelry. Other important applications include construction of laboratory crucibles and high temperature electric furnaces; in instruments as thermocouple elements; as wire; for electrical contacts; as electrodes; in dentistry; in cigarette lighters; and for coating missile and jet engine parts.Platinum also is used extensively as a catalyst in hydrogenation, dehydrogenation, oxidation, isomerization, carbonylation, and hydrocracking. Also, it is used in organic synthesis and petroleum refining. Like palladium, platinum also exhibits remarkable ability to absorb hydrogen. An important application of platinum is in the catalytic oxidation of ammonia in Ostwald's process in the manufacture of nitric acid. Platinum is installed in the catalytic converters in automobile engines for pollution control.
Description
Platinum was discovered in Colombia, South America by Ulloa in 1735 and six years later in 1741 by Wood. The metal was isolated from native platinum by Delisle in 1775 and produced in malleable form by Chabaneau in 1786. Wollaston in 1803 developed a method of obtaining pure malleable platinum from crude platinum by extraction with aqua regia. The process led to the discovery of two other platinum group metals, palladium and rhodium, that were found in the aqua regia extract after platinum precipitated. Platinum derived its name from platina originating from the Spanish word plata for silver, because it was thought to be a trivial unwanted material associated with gold in gold mines of Central America. Platinum occurs in nature as a bright-white cubic crystalline solid with metallic luster associated with other noble metals of its group. Platinum also occurs as the mineral sperrylite, PtAs2, found as tin-white brittle cubic crystals containing 52−57% platinum in certain nickel-bearing deposits. Some other minerals of platinum are cooperite PtS (Pt 80-86%); and braggite(Pt, Pd, Ni)S (Pt 58-60%). The abundance of platinum in the earth’s crust is estimated to be 0.005 mg/kg.
Occurrence
Platinum is the 75th most abundant element and, unlike many elements, is found in itspure elemental form in nature, as are deposits of silver and gold. Platinum is widely distributedover the Earth and is mined mainly in the Ural Mountains in Russia and in South Africa,Alaska, the western United States, Columbia in South America, and Ontario in Canada.When found in the mineral sperrylite (PtAs2), it is dissolved with aqua regia to form a precipitatecalled “sponge” that is then converted into platinum metal. It is also recovered as aby-product of nickel mining, mainly in Ontario, Canada.
History
Discovered in South America by Ulloa in 1735 and by Wood in 1741. Platinum was used by pre-Columbian Indians. Platinum occurs native, accompanied by small quantities of iridium, osmium, palladium, ruthenium, and rhodium, all belonging to the same group of metals. These are found in the alluvial deposits of the Ural mountains and in Columbia. Sperrylite (PtAs2), occurring with the nickel-bearing deposits of Sudbury, Ontario, is a source of a considerable amount of metal. The large production of nickel offsets there being only one part of the platinum metals in two million parts of ore. The largest supplier of the platinum group of metals is now South Africa, followed by Russia and Canada. Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda–lime–silica glass, and is therefore used to make sealed electrodes in glass systems. The metal does not oxidize in air at any temperature, but is corroded by halogens, cyanides, sulfur, and caustic alkalis. It is insoluble in hydrochloric and nitric acid, but dissolves when they are mixed as aqua regia, forming chloroplatinic acid (H2PtCl6), an important compound. Natural platinum contains six isotopes, one of which, 190Pt, is radioactive with a long half-life. Thirtyseven other radioactive isotopes and isomers are recognized. The metal is used extensively in jewelry, wire, and vessels for laboratory use, and in many valuable instruments including thermocouple elements. It is also used for electrical contacts, corrosion-resistant apparatus, and in dentistry. Platinum–cobalt alloys have magnetic properties. One such alloy made of 76.7% Pt and 23.3% Co, by weight, is an extremely powerful magnet that offers a B-H (max) almost twice that of Alnico V. Platinum resistance wires are used for constructing hightemperature electric furnaces. The metal is used for coating missile nose cones, jet engine fuel nozzles, etc., which must perform reliably for long periods of time at high temperatures. The metal, like palladium, absorbs large volumes of hydrogen, retaining it at ordinary temperatures but giving it up at red heat. In the finely divided state platinum is an excellent catalyst, having long been used in the contact process for producing sulfuric acid. It is also used as a catalyst in cracking petroleum products. There is also much current interest in the use of platinum as a catalyst in fuel cells and in its use as antipollution devices for automobiles. Platinum anodes are extensively used in cathodic protection systems for large ships and ocean-going vessels, pipelines, steel piers, etc. Pure platinum wire will glow red hot when placed in the vapor of methyl alcohol. It acts here as a catalyst, converting the alcohol to formaldehyde. This phenomenon has been used commercially to produce cigarette lighters and hand warmers. Hydrogen and oxygen explode in
Uses
Platinum is a white noble metal that looks very much like metallic silver found in copper ore. The name platinum comes from the Spanish word plata, meaning silver. Platinum compounds were used in the platinum printing process and for toning silver images.
Uses
manufacture of apparatus for laboratory and industrial use, thermocouples, platinum resistance thermometers, acidproof containers, electrodes, etc. In dentistry; jewelry; electroplating. As oxidation catalyst in manufacture of acetic acid, nitric acid from ammonia, manufacture of sulfuric acid; control of automotive emissions.
Uses
Because of its chemical and physical properties, platinum has many uses. It is used widelyin jewelry making and is often mixed with gold to improve gold’s strength and durability.In the early 1800s it was known that when hydrogen is passed over powdered platinum, thehydrogen ignites without being heated and without consuming the platinum. This propertyled to a major use of platinum as a catalyst to speed up chemical reactions. An example is presentin the internal combustion engine that produces harmful gases. Gasoline fuel burns insidethe engine, as compared to the steam engine, where the fuel is burned outside the engine. Thecatalytic converter in automobiles uses a platinum-coated ceramic grid in the exhaust systemto convert unburned fuel to carbon dioxide and water. The platinum in the converter will lastas long as the car since a catalyst is not consumed by the chemical reaction.Fuel Cells: As a catalyst, platinum is used for hydrogenation of liquid vegetable oils to produce solidforms of the oil, such as margarine. It is also used in the cracking process that breaks downlarge crude oil molecules into smaller, more useful molecules, such as gasoline. The catalyticproperties of platinum make it useful in the production of sulfuric acid (H2SO4) and in fuelcells that unite hydrogen and oxygen to produce electricity.
General Description
Silvery, whitish-gray, malleable, ductile metal. Mp: 1772°C; bp: 2187°C. Density: 21.45 g cm-3 at room conditions (very dense). Also shipped as a finely divided powder (Platinum black), as a sponge, and as particles deposited on a supporting material such as alumina. Has strong catalytic activity in these forms; finely divided Platinum can be dangerous to handle in the vicinity of other chemicals on this account. Used Platinum catalysts are particularly dangerous and can be explosive.