Editing Platinum (section)

==Applications==
[[File:Aufgeschnittener Metall Katalysator für ein Auto.jpg|thumb|Cutaway view of a [[Catalytic converter|metal-core catalytic converter]]]]

Of the 218&nbsp;tonnes of platinum sold in 2014, 98&nbsp;tonnes were used for [[vehicle emissions control]] devices (45%), 74.7&nbsp;tonnes for jewelry (34%), 20.0&nbsp;tonnes for chemical production and petroleum refining (9.2%), and 5.85&nbsp;tonnes for electrical applications such as hard disk drives (2.7%). The remaining 28.9&nbsp;tonnes went to various other minor applications, such as medicine and biomedicine, glassmaking equipment, investment, electrodes, anticancer drugs, [[oxygen sensor]]s, [[spark plug]]s and turbine engines.<ref name="usgs2014-yearbook">{{cite web|url=http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2014-plati.pdf|author=Loferski, P. J.|title=2014 Minerals Yearbook; Platinum-group metals|publisher=USGS Mineral Resources Program|date=July 2016|access-date=11 July 2016|url-status=live|archive-url=https://web.archive.org/web/20160818074038/http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2014-plati.pdf|archive-date=18 August 2016|df=dmy-all}}</ref>

===Catalyst===
The most common use of platinum is as a [[catalyst]] in chemical reactions, often as [[platinum black]]. It has been employed as a catalyst since the early 19th century, when platinum powder was used to catalyze the ignition of hydrogen. In an automobile [[catalytic converter]], it completes the combustion of low concentrations of unburned hydrocarbons from the exhaust into carbon dioxide and water vapor.  Platinum is also used in the petroleum industry as a catalyst in a number of separate processes, but especially in [[catalytic reforming]] of straight-run [[Petroleum naphtha|naphthas]] into higher-octane gasoline that becomes rich in aromatic compounds. {{chem2|PtO2}}, also known as [[Adams' catalyst]], is used as a hydrogenation catalyst, specifically for [[vegetable oil]]s.<ref name="krebs" /> Platinum also strongly catalyzes the decomposition of [[hydrogen peroxide]] into [[water]] and oxygen<ref>{{cite book|title = General Chemistry: Principles & Modern Applications|author = Petrucci, Ralph H.|edition = 9th|page = 606|publisher = Prentice Hall|date = 2007|isbn = 978-0-13-149330-8|url = https://archive.org/details/generalchemistry0000petr|url-access = registration}}</ref> and it is used in [[fuel cell]]s<ref>{{cite book|title=Fuel Cell System Explained|first1=James|last1=Laramie|first2=Andrew|last2=Dicks|publisher=John Wiley & Sons Ltd.|year=2003|isbn=978-0-470-84857-9}}</ref> as a catalyst for the reduction of [[oxygen]].<ref>{{cite journal|title=A general approach to the size- and shape-controlled synthesis of platinum nanoparticles and their catalytic reduction of oxygen|first1=C.|last1=Wang|first2=H.|last2=Daimon|first3=T.|last3=Onodera|first4=T.|last4=Koda|first5=S.|last5=Sun|doi=10.1002/anie.200800073|journal=Angewandte Chemie International Edition|volume=47|issue=19|pages=3588–91|year=2008|pmid=18399516}}</ref>

===Green energy transition===
As a fuel cell catalyst, platinum enables hydrogen and oxygen reactions to take place at an optimum rate. It is used in platinum-based [[proton-exchange membrane fuel cell|proton exchange membrane (PEM)]] technologies required in [[green hydrogen]] production as well as [[fuel cell vehicle|fuel cell electric vehicle adoption (FCEV)]].<ref>{{citation |url=https://www.sbma.org.sg/media-centre/publication/crucible-issue-28/why-platinum-is-a-strategically-important-metal/ |website=Singapore Bullion Market Association |last=Sterck |first=Edward |title=Why Platinum is a Strategically Important Metal|date=17 November 2023 }}</ref><ref>{{cite journal |vauthors=Rasmussen KD, Wenzel H, Bangs C, Petavratzi E, Liu G |year=2019 |title=Platinum demand and potential bottlenecks in the global green transition: A dynamic material flow analysis. |journal=Environmental Science & Technology |publisher=American Chemical Society |volume=53 |issue=19 |pages=11541–11551 |doi=10.1021/acs.est.9b01912 |pmid=31479264 |bibcode=2019EnST...5311541R |url=http://nora.nerc.ac.uk/id/eprint/526203/1/Pt%20Demand%20and%20Green%20Transition%20V13_FINAL.pdf }}</ref>

===Standard===
[[File:Platinum-Iridium meter bar.jpg|thumb|upright=1.2|right|Prototype International Meter bar made by [[Johnson Matthey]]]]
From 1889 to 1960, the [[metre|meter]] was defined as the length of a platinum-iridium (90:10) alloy bar, known as the [[History of the meter#International prototype metre|international prototype meter]]. The previous bar was made of platinum in 1799. Until May 2019, the [[kilogram]] was defined as the mass of the [[international prototype of the kilogram]], a cylinder of the same platinum-iridium alloy made in 1879.<ref name="meter">{{cite book|doi = 10.1007/978-3-642-00738-5_4|date = 2010|last1 = Gupta|first1 = S. V.| chapter=Metre Convention and Evolution of Base Units |page = 47 |title=Units of Measurement |volume = 122|series = Springer Series in Materials Science|isbn = 978-3-642-00777-4| s2cid=150519250 }}</ref>

The Standard Platinum [[Resistance Thermometer]] (SPRT) is one of the four types of thermometers used to define the [[International Temperature Scale of 1990]] (ITS-90), the international calibration standard for temperature measurements. The resistance wire in the thermometer is made of pure platinum (NIST manufactured the wires from platinum bar stock with a chemical purity of 99.999% by weight).<ref name="bipm">{{cite web|title=Guide to the Realization of the ITS-90 - Platinum Resistance Thermometry|publisher=[[International Committee for Weights and Measures]]|url=https://www.bipm.org/utils/common/pdf/ITS-90/Guide-ITS-90-Platinum-Resistance-Thermometry.pdf|access-date=23 October 2020|archive-date=24 February 2021|archive-url=https://web.archive.org/web/20210224094446/https://www.bipm.org/utils/common/pdf/ITS-90/Guide-ITS-90-Platinum-Resistance-Thermometry.pdf|url-status=dead}}</ref><ref name="nist">{{cite web|title=Standard Reference Material 1750:Standard Platinum Resistance Thermometers,13.8033 K to 429.7485 K|publisher=[[NIST]]|url=https://www.nist.gov/system/files/documents/srm/SP260-139.PDF}}</ref> In addition to laboratory uses, Platinum Resistance Thermometry (PRT) also has many industrial applications, industrial standards include ASTM E1137 and IEC 60751.

The [[standard hydrogen electrode]] also uses a [[platinized]] platinum electrode due to its corrosion resistance, and other attributes.<ref name="HollemanAF">{{cite journal|last1 = Feltham|first1 = A. M.|last2 = Spiro|first2 = Michael|title = Platinized platinum electrodes|journal = Chemical Reviews|volume = 71|pages = 177–193|date = 1971|doi = 10.1021/cr60270a002|issue = 2}}</ref>

=== As an investment ===
{{main|Platinum as an investment|Platinum coin}}

Platinum is a [[precious metal]] [[commodity]]; its [[bullion]] has the [[ISO currency code]] of XPT. Coins, bars, and ingots are traded or collected. Platinum finds use in jewellery, usually as a 90–95% alloy, due to its inertness. It is used for this purpose for its prestige and inherent bullion value.<ref>{{cite web|url = http://www.professionaljeweler.com/archives/articles/2004/aug04/0804fys.html|title = Professional Jeweler's Magazine Archives, issue of August 2004|access-date = 19 June 2011|url-status = live|archive-url = https://web.archive.org/web/20110928115918/http://www.professionaljeweler.com/archives/articles/2004/aug04/0804fys.html|archive-date = 28 September 2011|df = dmy-all}}</ref><ref>{{cite web|url = http://www.diamondcuttersintl.com/a-platinum-primer|title = Platinum primer|publisher = Diamond Cutters International|access-date = 18 June 2011|url-status = live|archive-url = https://web.archive.org/web/20110927045943/http://www.diamondcuttersintl.com/a-platinum-primer/|archive-date = 27 September 2011|df = dmy-all|date = 2008-12-12}}</ref>

In [[watchmaking]], [[Vacheron Constantin]], [[Patek Philippe]], [[Rolex]], [[Breitling SA|Breitling]], and other companies use platinum in some of their watches. Watchmakers appreciate the unique properties of platinum, as it is more durable than gold, but similar to gold, it does not tarnish.<ref>{{cite web|url = http://watches.infoniac.com/index.php?page=post&id=44|title = Unknown Facts about Platinum|publisher = watches.infoniac.com|access-date = 9 September 2008|url-status = dead|archive-url = https://web.archive.org/web/20080921210250/http://watches.infoniac.com/index.php?page=post&id=44|archive-date = 21 September 2008|df = dmy-all}}</ref>

During periods of sustained economic stability and growth, the price of platinum tends to be as much as twice the price of gold, whereas during periods of economic uncertainty,<ref name="TheSpeculativeInvestor">{{cite web|title = Platinum versus Gold|publisher = The Speculative Invertor|url = http://www.speculative-investor.com/new/article150402.html|date = 14 April 2002|url-status = dead|archive-url = https://web.archive.org/web/20081026073657/http://www.speculative-investor.com/new/article150402.html|archive-date = 26 October 2008|df = dmy-all}}</ref> the price of platinum tends to decrease due to reduced industrial demand, falling below the price of gold. Gold prices are more stable in slow economic times, as gold is considered a safe haven.<ref>{{cite journal|title=Are safe haven assets really safe during the 2008 global financial crisis and COVID-19 pandemic? |first1= MB |last1=Hasan |first2=MK |last2=Hassan |first3=MM |last3=Rashid |first4=Y |last4=Alhenawi |doi=10.1016/j.gfj.2021.100668 |journal=Global Finance Journal |issue=3 |pages=1–11 |year=2021 |volume= 50 |pmid=8575456|pmc=8575456 }}</ref> Although gold is also used in industrial applications, especially in electronics due to its use as a conductor, its demand is not so driven by industrial uses.<ref>{{cite journal|title=An overview of global gold market and gold price forecasting |first1=Shahriar |last1=Shafiee |first2=Erkan |last2=Topal |doi=10.1016/j.resourpol.2010.05.004 |journal=Resources Policy |issue=3 |pages=178–189 |year=2010|volume=35 |bibcode=2010RePol..35..178S }}</ref> In the 18th century, platinum's rarity made King [[Louis XV of France]] declare it the only metal fit for a king.<ref name="mineralszone">{{cite web |title=Platinum |publisher=Minerals Zone |url=http://www.mineralszone.com/minerals/platinum.html |access-date=9 September 2008 |url-status=dead |archive-url=https://web.archive.org/web/20081012110510/http://www.mineralszone.com/minerals/platinum.html |archive-date=12 October 2008 |df=dmy-all }}</ref>

<gallery widths="200px" heights="160px">
File:One litre of Platinum.jpg|1,000 cubic centimeters of 99.9% pure platinum, worth about US$696,000 at 29 Jun 2016 prices<ref name="WolframAlpha">{{cite web|title=21.09kg Pt|url=http://www.wolframalpha.com/input/?i=21.09kg+Pt|publisher=WolframAlpha|access-date=14 July 2012|url-status=live|archive-url=https://web.archive.org/web/20140823232339/http://www.wolframalpha.com/input/?i=21.09kg+Pt|archive-date=23 August 2014|df=dmy-all}}</ref>
File:Platinum price.webp|Platinum price 1970–2022
</gallery>

===Other uses===
In the laboratory, platinum wire is used for electrodes; platinum pans and supports are used in [[thermogravimetric analysis]] because of the stringent requirements of chemical inertness upon heating to high temperatures (~1000&nbsp;°C). Platinum is used as an alloying agent for various metal products, including fine wires, noncorrosive laboratory containers, medical instruments, dental prostheses, electrical contacts, and thermocouples. Platinum-cobalt, an alloy of roughly three parts platinum and one part cobalt, is used to make relatively strong permanent [[magnet]]s.<ref name="krebs" /> Platinum-based anodes are used in ships, pipelines, and steel piers.<ref name="CRC" /> Platinum drugs are used to treat a wide variety of cancers, including testicular and ovarian carcinomas, melanoma, small-cell and non-small-cell lung cancer, myelomas and lymphomas.<ref name="apps">{{cite journal |last1=Apps |first1=Michael G |last2=Choi |first2=Eugene H Y |last3=Wheate |first3=Nial J |title=The state-of-play and future of platinum drugs |journal=Endocrine-Related Cancer |date=August 2015 |volume=22 |issue=4 |pages=R219–R233 |doi=10.1530/ERC-15-0237 |publisher=Society for Endocrinology|pmid=26113607 |doi-access=free |hdl=2123/24426 |hdl-access=free }}</ref>

===Symbol of prestige in marketing===
{{see also|Platinum album|Platinum (color)}}

Platinum's rarity as a metal has caused advertisers to associate it with exclusivity and wealth. "Platinum" [[Payment card|debit and credit cards]] have greater privileges than "[[gold]]" cards.<ref>{{cite journal|last1 = Gwin|first1 = John|title = Pricing Financial Institution Products|journal = Journal of Professional Services Marketing|volume = 1|pages = 91–99|date = 1986|doi = 10.1300/J090v01n03_07|issue = 3}}</ref> "[[RIAA certification|Platinum awards]]" are frequently the highest, or near highest possible, often ranking above "gold", "[[silver]]" and "[[bronze]]". For example, in the United States, a musical album that has sold more than 1&nbsp;million copies will be credited as "platinum", though an album that has sold more than 10&nbsp;million copies will be certified as "diamond".<ref>{{cite book|page = 126|url = https://books.google.com/books?id=dYFv3ifE0f4C&pg=PA126|title = Big Bang Baby: The Rock Trivia Book|isbn = 978-0-88882-219-2|author1 = Crouse, Richard|date = 1 May 2000| publisher=Dundurn |url-status = live|archive-url = https://web.archive.org/web/20170324034507/https://books.google.com/books?id=dYFv3ifE0f4C&pg=PA126|archive-date = 24 March 2017|df = dmy-all}}</ref> Some products, such as blenders and vehicles, with a silvery-white color are identified as "platinum". Platinum is considered a precious metal, although its use is not as common as the use of gold or silver. The frame of the [[Crown of Queen Elizabeth The Queen Mother]], manufactured for her coronation as Consort of [[King George VI]], is made of platinum. It was the first British crown to be made of this particular metal.<ref>{{cite book|url = https://books.google.com/books?id=SImTll3uupIC&pg=PA312|title = The Signs and Symbols Bible: The Definitive Guide to Mysterious Markings|isbn = 978-1-4027-7004-3|author1 = Gauding, Madonna|date = 6 October 2009| publisher=Sterling Publishing Company |url-status = live|archive-url = https://web.archive.org/web/20170324014245/https://books.google.com/books?id=SImTll3uupIC&pg=PA312|archive-date = 24 March 2017|df = dmy-all}}</ref>