The Yamaha RX-Z 135 is a two-stroke naked bike manufactured by Yamaha Motor Corporation . Debuting in April 1985, the RX-Z was very popular in Malaysia and Singapore and Thailand and was sold from 1985 until production was ended in 2011.
108-549: In 2004, the RX-Z had a restyle and a catalytic converter was installed. The first generation of the RX-Z (1985) was originally equipped with a five-speed transmission with solid front disc brake . The model shared the same platform and chassis as its predecessor the RX-135 . The RX-Z became very popular among young motorcyclists in Singapore and Malaysia. A few years later in 1990, the engine
216-585: A computerized closed-loop feedback fuel injection system using one or more oxygen sensors (also known as Lambda Sonds or sensors). Other variants combined three-way converters with carburetors equipped with feedback mixture control were used. An unregulated three-way converter features the same chemical processes but without the oxygen sensor, which meant higher NO x emissions, particularly under partial loads. These were low-cost solutions, typically used for retrofitting to older cars or for smaller, cheaper cars. Three-way converters are effective when
324-546: A platinized platinum electrode due to its corrosion resistance, and other attributes. 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. Jewellery trade publications advise jewellers to present minute surface scratches (which they term patina ) as
432-512: A reagent such as ammonia to reduce the NO x into nitrogen and water. Ammonia is supplied to the catalyst system by the injection of urea into the exhaust, which then undergoes thermal decomposition and hydrolysis into ammonia. The urea solution is also referred to as diesel exhaust fluid (DEF). Diesel exhaust contains relatively high levels of particulate matter. Catalytic converters remove only 20–40% of PM so particulates are cleaned up by
540-796: A British metallurgist , found various samples of Colombian platinum in Jamaica, which he sent to William Brownrigg for further investigation. In 1750, after studying the platinum sent to him by Wood, Brownrigg presented a detailed account of the metal to the Royal Society , stating that he had seen no mention of it in any previous accounts of known minerals. Brownrigg also made note of platinum's extremely high melting point and refractoriness toward borax . Other chemists across Europe soon began studying platinum, including Andreas Sigismund Marggraf , Torbern Bergman , Jöns Jakob Berzelius , William Lewis , and Pierre Macquer . In 1752, Henrik Scheffer published
648-420: A catalytic combustor for gas turbines in the early 1970s, allowing combustion without significant formation of nitrogen oxides and carbon monoxide. Four-way catalytic converters have also been developed which also remove particulates from engine exhaust; since most of these particulates are unburned hydrocarbons, they can be burned to convert them into carbon dioxide. The catalytic converter's construction
756-454: A catalytic converter for any reason other than its direct and immediate replacement. Nevertheless, some vehicle owners remove or "gut" the catalytic converter on their vehicle. In such cases, the converter may be replaced by a welded-in section of ordinary pipe or a flanged "test pipe", ostensibly meant to check if the converter is clogged by comparing how the engine runs with and without the converter. This facilitates temporary reinstallation of
864-637: A catalytic converter was patented by Eugene Houdry , a French mechanical engineer. Houdry was an expert in catalytic oil refining, having invented the catalytic cracking process that all modern refining is based on today. Houdry moved to the United States in 1930 to live near the refineries in the Philadelphia area and develop his catalytic refining process. When the results of early studies of smog in Los Angeles were published, Houdry became concerned about
972-408: A common housing; however, in some instances, they may be housed separately. A three-way catalytic converter does three simultaneous tasks: Reduction of nitrogen oxides to nitrogen (N 2 ) Oxidation of carbon, hydrocarbons, and carbon monoxide to carbon dioxide These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above
1080-421: A conductor, its demand is not so driven by industrial uses. In the 18th century, platinum's rarity made King Louis XV of France declare it the only metal fit for a king. 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 °C). Platinum
1188-472: A dark-red transparent crystalline compound has been shown to contain Pt anions. Platinum also exhibits negative oxidation states at surfaces reduced electrochemically. The negative oxidation states exhibited by platinum are unusual for metallic elements, and they are attributed to the relativistic stabilization of the 6s orbitals. It is predicted that even the cation PtO 4 in which platinum exists in
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#17328584307691296-437: A desirable feature in an attempt to enhance value of platinum products. In watchmaking , Vacheron Constantin , Patek Philippe , Rolex , Breitling , and other companies use platinum for producing their limited edition watch series. Watchmakers appreciate the unique properties of platinum, as it neither tarnishes nor wears out (the latter quality relative to gold). During periods of sustained economic stability and growth,
1404-427: A detailed scientific description of the metal, which he referred to as "white gold", including an account of how he succeeded in fusing platinum ore with the aid of arsenic . Scheffer described platinum as being less pliable than gold, but with similar resistance to corrosion. Karl von Sickingen researched platinum extensively in 1772. He succeeded in making malleable platinum by alloying it with gold, dissolving
1512-414: A federal criminal offense. Platinum Platinum is a chemical element ; it has symbol Pt and atomic number 78. It is a dense , malleable , ductile , highly unreactive, precious , silverish-white transition metal . Its name originates from Spanish platina , a diminutive of plata "little silver". Platinum is a member of the platinum group of elements and group 10 of
1620-468: A head gasket leak, can also cause high unburned hydrocarbons. Emissions regulations vary considerably from jurisdiction to jurisdiction. Most automobile spark-ignition engines in North America have been fitted with catalytic converters since 1975, and the technology used in non-automotive applications is generally based on automotive technology. In many jurisdictions, it is illegal to remove or disable
1728-492: A limit of phosphorus concentration in engine oils was adopted in the API SM and ILSAC GF-4 specifications. Depending on the contaminant, catalyst poisoning can sometimes be reversed by running the engine under a very heavy load for an extended period of time. The increased exhaust temperature can sometimes vaporize or sublimate the contaminant, removing it from the catalytic surface. However, removal of lead deposits in this manner
1836-484: A liquid. Platinum is paramagnetic , whereas nickel and iron are both ferromagnetic . These two impurities are thus removed by running an electromagnet over the mixture. Because platinum has a higher melting point than most other substances, many impurities can be burned or melted away without melting the platinum. Finally, platinum is resistant to hydrochloric and sulfuric acids, whereas other substances are readily attacked by them. Metal impurities can be removed by stirring
1944-690: A pre-cat, a small catalytic converter upstream of the main catalytic converter which heats up faster on vehicle start up, reducing the emissions associated with cold starts. A pre-cat is most commonly used by an auto manufacturer when trying to attain the Ultra Low Emissions Vehicle (ULEV) rating, such as on the Toyota MR2 Roadster. Catalytic converters have proven to be reliable and effective in reducing noxious tailpipe emissions. However, they also have some shortcomings in use, and also adverse environmental effects in production: Because of
2052-405: A precisely controlled air-fuel mixture that quickly and continually cycles between lean and rich combustion. Oxygen sensors monitor the exhaust oxygen content before and after the catalytic converter, and the engine control unit uses this information to adjust the fuel injection so as to prevent the first ( NO x reduction) catalyst from becoming oxygen-loaded, while simultaneously ensuring
2160-654: A soot trap or diesel particulate filter (DPF). In the U.S., all on-road light, medium, and heavy-duty diesel-powered vehicles built after 1 January 2007, are subject to diesel particulate emission limits, and so are equipped with a 2-way catalytic converter and a diesel particulate filter. As long as the engine was manufactured before 1 January 2007, the vehicle is not required to have the DPF system. This led to an inventory runup by engine manufacturers in late 2006 so they could continue selling pre-DPF vehicles well into 2007. For lean-burn spark-ignition engines, an oxidation catalyst
2268-414: A thin surface film of PtO 2 that can be easily removed by heating to about 400 °C. The most common oxidation states of platinum are +2 and +4. The +1 and +3 oxidation states are less common, and are often stabilized by metal bonding in bimetallic (or polymetallic) species. Tetracoordinate platinum(II) compounds tend to adopt 16-electron square planar geometries. Although elemental platinum
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#17328584307692376-452: Is Pt , comprising 33.83% of all platinum. It is the only stable isotope with a non-zero spin . The spin of / 2 and other favourable magnetic properties of the nucleus are utilised in Pt NMR . Due to its spin and large abundance, Pt satellite peaks are also often observed in H and P NMR spectroscopy ( e.g., for Pt-phosphine and Pt-alkyl complexes). Pt
2484-505: Is a lustrous, ductile , and malleable , silver-white metal. Platinum is more ductile than gold , silver or copper , thus being the most ductile of pure metals, but it is less malleable than gold. Its physical characteristics and chemical stability make it useful for industrial applications. Its resistance to wear and tarnish is well suited to use in fine jewellery . Platinum has excellent resistance to corrosion . Bulk platinum does not oxidize in air at any temperature, but it forms
2592-561: Is a major source of platinum associated with nickel ores in the Sudbury Basin deposit in Ontario , Canada . At Platinum, Alaska , about 17,000 kg (550,000 ozt) was mined between 1927 and 1975. The mine ceased operations in 1990. The rare sulfide mineral cooperite , (Pt,Pd,Ni)S , contains platinum along with palladium and nickel. Cooperite occurs in the Merensky Reef within
2700-449: Is also used in the petroleum industry as a catalyst in a number of separate processes, but especially in catalytic reforming of straight-run naphthas into higher-octane gasoline that becomes rich in aromatic compounds. PtO 2 , also known as Adams' catalyst , is used as a hydrogenation catalyst, specifically for vegetable oils . Platinum also strongly catalyzes the decomposition of hydrogen peroxide into water and oxygen and it
2808-446: Is an exhaust emission control device which converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction . Catalytic converters are usually used with internal combustion engines fueled by gasoline or diesel , including lean-burn engines, and sometimes on kerosene heaters and stoves. The first widespread introduction of catalytic converters
2916-455: Is an extremely rare metal, occurring at a concentration of only 0.005 ppm in Earth's crust . Sometimes mistaken for silver, platinum is often found chemically uncombined as native platinum and as alloy with the other platinum-group metals and iron mostly. Most often the native platinum is found in secondary deposits in alluvial deposits. The alluvial deposits used by pre-Columbian people in
3024-425: 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. Its most important application is in automobiles as a catalytic converter , which allows the complete combustion of low concentrations of unburned hydrocarbons from the exhaust into carbon dioxide and water vapor. Platinum
3132-439: Is as follows: Upon failure, a catalytic converter can be recycled into scrap . The precious metals inside the converter, including platinum, palladium, and rhodium, are extracted. Catalytic converters require a temperature of 400 °C (750 °F) to operate effectively. Therefore, they are placed as close to the engine as possible, or one or more smaller catalytic converters (known as "pre-cats") are placed immediately after
3240-411: Is generally unreactive, it is attacked by chlorine , bromine , iodine , and sulfur . It reacts vigorously with fluorine at 500 °C (932 °F) to form platinum tetrafluoride . Platinum is insoluble in hydrochloric and nitric acid , but dissolves in hot aqua regia (a mixture of nitric and hydrochloric acids), to form aqueous chloroplatinic acid , H 2 PtCl 6 : As a soft acid ,
3348-467: Is highly valuable and is a major precious metal commodity . Platinum is one of the least reactive metals . It has remarkable resistance to corrosion , even at high temperatures, and is therefore considered a noble metal . Consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sands of various rivers, it was first used by pre-Columbian South American natives to produce artifacts. It
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3456-459: Is one such example. Hexachloroplatinic acid mentioned above is probably the most important platinum compound, as it serves as the precursor for many other platinum compounds. By itself, it has various applications in photography, zinc etchings, indelible ink , plating, mirrors, porcelain coloring, and as a catalyst. Treatment of hexachloroplatinic acid with an ammonium salt, such as ammonium chloride , gives ammonium hexachloroplatinate , which
3564-462: Is permitted and a rich mixture is commanded to increase power and prevent exhaust gas temperature from exceeding design limits. This presents a challenge for control system and catalyst design. During such operations, large amounts of unburnt HC are produced by the engine, well beyond the capacity of the catalyst to release oxygen. The surface of the catalyst quickly becomes saturated with HC. When returning to lower power output and leaner air–fuel ratios,
3672-438: Is relatively insoluble in ammonium solutions. Heating this ammonium salt in the presence of hydrogen reduces it to elemental platinum. Potassium hexachloroplatinate is similarly insoluble, and hexachloroplatinic acid has been used in the determination of potassium ions by gravimetry . When hexachloroplatinic acid is heated, it decomposes through platinum(IV) chloride and platinum(II) chloride to elemental platinum, although
3780-415: Is the first of a series of square planar platinum(II)-containing chemotherapy drugs. Others include carboplatin and oxaliplatin . These compounds are capable of crosslinking DNA , and kill cells by similar pathways to alkylating chemotherapeutic agents . (Side effects of cisplatin include nausea and vomiting, hair loss, tinnitus, hearing loss, and nephrotoxicity.) Organoplatinum compounds such as
3888-426: Is the least abundant at only 0.01%. Of the naturally occurring isotopes, only Pt is unstable, though it decays with a half-life of 6.5 × 10 years, causing an activity of 15 Bq /kg of natural platinum. Other isotopes can undergo alpha decay , but their decay has never been observed, therefore they are considered stable. Platinum also has 38 synthetic isotopes ranging in atomic mass from 165 to 208, making
3996-432: 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 magnets . Platinum-based anodes are used in ships, pipelines, and steel piers. Platinum drugs are used to treat
4104-400: Is used in fuel cells as a catalyst for the reduction of oxygen . 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 (PEM) technologies required in green hydrogen production as well as fuel cell electric vehicle adoption (FCEV) . From 1889 to 1960, the meter was defined as
4212-437: Is used in the glass industry to manipulate molten glass, which does not " wet " platinum. As a heavy metal , it leads to health problems upon exposure to its salts ; but due to its corrosion resistance, metallic platinum has not been linked to adverse health effects. Compounds containing platinum, such as cisplatin , oxaliplatin and carboplatin , are applied in chemotherapy against certain types of cancer. Pure platinum
4320-407: Is used in the same manner as in a diesel engine. Emissions from lean burn spark ignition engines are very similar to emissions from a diesel compression ignition engine. Many vehicles have a close-coupled catalytic converter located near the engine's exhaust manifold . The converter heats up quickly, due to its exposure to the very hot exhaust gases, allowing it to reduce undesirable emissions during
4428-495: Is usually in response to government regulation, either through environmental regulation or through health and safety regulations. Catalytic converter prototypes were first designed in France at the end of the 19th century, when only a few thousand "oil cars" were on the roads; these prototypes had inert clay-based materials coated with platinum , rhodium , and palladium and sealed into a double metallic cylinder. A few decades later,
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4536-404: Is usually not possible because of lead's high boiling point. Any condition that causes abnormally high levels of unburned hydrocarbons (raw or partially burnt fuel or oils) to reach the converter will tend to significantly elevate its temperature bringing the risk of a meltdown of the substrate and resultant catalytic deactivation and severe exhaust restriction. These conditions include failure of
4644-746: The Pt ion has a great affinity for sulfide and sulfur ligands. Numerous DMSO complexes have been reported and care is taken in the choosing of reaction solvents. In 2007, the German scientist Gerhard Ertl won the Nobel Prize in Chemistry for determining the detailed molecular mechanisms of the catalytic oxidation of carbon monoxide over platinum ( catalytic converter ). Platinum has six naturally occurring isotopes : Pt , Pt , Pt , Pt , Pt , and Pt . The most abundant of these
4752-750: The Bushveld complex , Gauteng , South Africa . In 1865, chromites were identified in the Bushveld region of South Africa, followed by the discovery of platinum in 1906. In 1924, the geologist Hans Merensky discovered a large supply of platinum in the Bushveld Igneous Complex in South Africa. The specific layer he found, named the Merensky Reef , contains around 75% of the world's known platinum. The large copper–nickel deposits near Norilsk in Russia , and
4860-569: The Chocó Department , Colombia are still a source for platinum-group metals. Another large alluvial deposit is in the Ural Mountains , Russia, and it is still mined. In nickel and copper deposits, platinum-group metals occur as sulfides (e.g., (Pt,Pd)S) , tellurides (e.g., PtBiTe ), antimonides (PdSb), and arsenides (e.g. PtAs 2 ), and as end alloys with nickel or copper. Platinum arsenide, sperrylite ( PtAs 2 ),
4968-599: The European Union and the United Kingdom since January 1, 1993 in order to comply with the Euro 1 emission standards . Faulty catalytic converters as well as undamaged early types of converters can restrict the flow of exhaust, which negatively affects vehicle performance and fuel economy. Modern catalytic converters do not significantly restrict exhaust flow. A 2006 test on a 1999 Honda Civic, for example, showed that removing
5076-572: 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). 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
5184-600: The Sudbury Basin , Canada , are the two other large deposits. In the Sudbury Basin, the huge quantities of nickel ore processed make up for the fact platinum is present as only 0.5 ppm in the ore. Smaller reserves can be found in the United States, for example in the Absaroka Range in Montana . In 2010, South Africa was the top producer of platinum, with an almost 77% share, followed by Russia at 13%; world production in 2010
5292-484: The U.S. Environmental Protection Agency 's new exhaust emissions regulations, most gasoline-powered vehicles manufactured from 1975 onwards are equipped with catalytic converters. Early catalytic converters were "two-way", combining oxygen with carbon monoxide (CO) and unburned hydrocarbons (HC, chemical compounds in fuel of the form C m H n ) to produce carbon dioxide (CO 2 ) and water (H 2 O). These stringent emission control regulations also resulted in
5400-505: The adulteration of gold with platinum impurities. In 1735, Antonio de Ulloa and Jorge Juan y Santacilia saw Native Americans mining platinum while the Spaniards were travelling through Colombia and Peru for eight years. Ulloa and Juan found mines with the whitish metal nuggets and took them home to Spain. Antonio de Ulloa returned to Spain and established the first mineralogy lab in Spain and
5508-404: The alternator , wiring or fuel lines, with potentially dangerous consequences. In 2023, bipartisan legislation to combat catalytic converter theft was introduced in the U.S. Senate . The Preventing Auto Recycling Thefts Act (PART Act) would mandate catalytic converters in new vehicles to come with traceable identification numbers. Additionally, the legislation would make catalytic converter theft
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#17328584307695616-570: The periodic table of elements . It has six naturally occurring isotopes . It is one of the rarer elements in Earth's crust , with an average abundance of approximately 5 μg /kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa , which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it
5724-510: The stoichiometric point. For gasoline combustion, this ratio is between 14.6 and 14.8 parts air to one part fuel, by weight. The ratio for autogas (or liquefied petroleum gas LPG), natural gas , and ethanol fuels can vary significantly for each, notably so with oxygenated or alcohol based fuels, with E85 requiring approximately 34% more fuel, requiring modified fuel system tuning and components when using those fuels. Engines fitted with regulated 3-way catalytic converters are equipped with
5832-486: The +10 oxidation state may be achievable. Zeise's salt , containing an ethylene ligand, was one of the first organometallic compounds discovered. Dichloro(cycloocta-1,5-diene)platinum(II) is a commercially available olefin complex, which contains easily displaceable cod ligands ("cod" being an abbreviation of 1,5-cyclooctadiene). The cod complex and the halides are convenient starting points to platinum chemistry. Cisplatin , or cis -diamminedichloroplatinum(II)
5940-567: The 218 tonnes of platinum sold in 2014, 98 tonnes were used for vehicle emissions control devices (45%), 74.7 tonnes for jewelry (34%), 20.0 tonnes for chemical production and petroleum refining (9.2%), and 5.85 tonnes for electrical applications such as hard disk drives (2.7%). The remaining 28.9 tonnes went to various other minor applications, such as medicine and biomedicine, glassmaking equipment, investment, electrodes, anticancer drugs, oxygen sensors , spark plugs and turbine engines. The most common use of platinum
6048-556: The RX-Z was one of the motorcycle models often associated with Mat Rempits . As a result, many Malay movies including Remp-It use the RX-Z in their movies. Present day and the RX-Z is very popular now in Malaysia, Singapore and Indonesia. Prices now are skyrocketing in Malaysia as in 2020 one hereby sold for 70,000 Malaysian Ringgit 'RX-Z Selling for RM70,000'. because it had rare and all original NOS Yamaha Genuine parts. Catalytic converter A catalytic converter
6156-448: The U.S. added catalytic systems to their vehicles to meet federal emissions requirements. Two techniques have been developed for the catalytic reduction of NO x emissions under lean exhaust conditions, selective catalytic reduction (SCR) and the NO x adsorber . Instead of precious metal-containing NO x absorbers, most manufacturers selected base-metal SCR systems that use
6264-413: The above antitumour agents, as well as soluble inorganic platinum complexes, are routinely characterised using Pt nuclear magnetic resonance spectroscopy . Archaeologists have discovered traces of platinum in the gold used in ancient Egyptian burials as early as 1200 BCE . For example, a small box from burial of Shepenupet II was found to be decorated with gold-platinum hieroglyphics. However,
6372-455: The air pump, which led to the development of the three-way catalytic converter. The two-way catalytic converter also continued to be used on certain, lower-cost cars in some markets such as Europe, where NO x emissions were not universally regulated until the introduction of the Euro 3 emissions standard in 2000. The three-way catalytic converters have the additional advantage of controlling
6480-444: The air–fuel mixture is brought back to slightly rich, at a small penalty in CO and HC oxidation efficiency, and the cycle repeats. Efficiency is improved when this oscillation around the stoichiometric point is small and carefully controlled. Closed-loop control under light to moderate load is accomplished by using one or more oxygen sensors in the exhaust system. When oxygen is detected by
6588-430: The alloy in hot aqua regia , precipitating the platinum with ammonium chloride , igniting the ammonium chloroplatinate, and hammering the resulting finely divided platinum to make it cohere. Franz Karl Achard made the first platinum crucible in 1784. He worked with the platinum by fusing it with arsenic, then later volatilizing the arsenic. Because the other platinum-family members were not discovered yet (platinum
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#17328584307696696-535: The area were bought secondhand through the antiquities trade rather than obtained by direct archeological excavation. To work the metal, they would combine gold and platinum powders by sintering . The resulting gold–platinum alloy would then be soft enough to shape with tools. The platinum used in such objects was not the pure element, but rather a naturally occurring mixture of the platinum group metals, with small amounts of palladium, rhodium, and iridium. The first European reference to platinum appears in 1557 in
6804-468: The car. Vehicles fitted with catalytic converters emit most of their total pollution during the first five minutes of engine operation; for example, before the catalytic converter has warmed up sufficiently to be fully effective. In the early 2000s it became common to place the catalyst converter right next to the exhaust manifold, close to the engine, for much quicker warm-up. In 1995, Alpina introduced an electrically heated catalyst. Called "E-KAT", it
6912-479: The catalyst at reducing NO x is good, and the production of NO x by the engine decreases. To maintain catalyst efficiency, the air–fuel ratio must stay close to stoichiometric and not remain rich or lean for too long. Closed-loop engine control systems are used for effective operation of three-way catalytic converters because of this continuous rich-lean balance required for effective NO x reduction and HC+CO oxidation. The control system allows
7020-412: The catalyst to release oxygen during slightly rich operating conditions, which oxidizes CO and HC under conditions that also favor the reduction of NOx. Before the stored oxygen is depleted, the control system shifts the air–fuel ratio to become slightly lean, improving HC and CO oxidation while storing additional oxygen in the catalyst material, at a small penalty in NO x reduction efficiency. Then
7128-520: The control system must prevent excessive oxygen from reaching the catalyst too quickly, as this will rapidly burn the HC in the already hot catalyst, potentially exceeding the design temperature limit of the catalyst. Excessive catalyst temperature can prematurely age the catalyst, reducing its efficiency before reaching its design lifetime. Excessive catalyst temperature can also be caused by cylinder misfire, which continuously flows unburnt HC combined with oxygen to
7236-409: The conversion of HC and CO is very efficient due to the available oxygen, oxidizing to H 2 O and CO 2 . Slightly rich of stoichiometric, the production of CO and unburnt HC by the engine starts to increase dramatically, available oxygen decreases, and the efficiency of the catalyst for oxidizing CO and HC decreases significantly, especially as stored oxygen becomes depleted. However, the efficiency of
7344-850: The converter in order to pass an emission test. In the United States, it is a violation of Section 203(a)(3)(A) of the 1990 amended Clean Air Act for a vehicle repair shop to remove a converter from a vehicle, or cause a converter to be removed from a vehicle, except in order to replace it with another converter, and Section 203(a)(3)(B) makes it illegal for any person to sell or to install any part that would bypass, defeat, or render inoperative any emission control system, device, or design element. Vehicles without functioning catalytic converters generally fail emission inspections. The automotive aftermarket supplies high-flow converters for vehicles with upgraded engines, or whose owners prefer an exhaust system with larger-than-stock capacity. xxx Catalytic converters have been mandatory on all new gasoline cars sold in
7452-605: The emission of nitric oxide (NO) and nitrogen dioxide (NO 2 ) (both together abbreviated with NO x and not to be confused with nitrous oxide (N 2 O) ). NO x are precursors to acid rain and smog . Since 1981, the three-way (oxidation-reduction) catalytic converters have been used in vehicle emission control systems in the United States and Canada; many other countries have also adopted stringent vehicle emission regulations that in effect require three-way converters on gasoline-powered vehicles. The reduction and oxidation catalysts are typically contained in
7560-427: The engine is operated within a narrow band of air–fuel ratios near the stoichiometric point. Total conversion efficiency falls very rapidly when the engine is operated outside of this band. Slightly lean of stoichiometric, the exhaust gases from the engine contain excess oxygen, the production of NO x by the engine increases, and the efficiency of the catalyst at reducing NO x falls off rapidly. However,
7668-432: The engine warm-up period. This is achieved by burning off the excess hydrocarbons which result from the extra-rich mixture required for a cold start. When catalytic converters were first introduced, most vehicles used carburetors that provided a relatively rich air-fuel ratio . Oxygen (O 2 ) levels in the exhaust stream were therefore generally insufficient for the catalytic reaction to occur efficiently. Most designs of
7776-578: The exhaust manifold. A 2-way (or "oxidation", sometimes called an "oxi-cat") catalytic converter has two simultaneous tasks: The two-way catalytic converter is widely used on diesel engines to reduce hydrocarbon and carbon monoxide emissions. They were also used on gasoline engines in American and Canadian automobile markets until 1981. Because of their inability to control oxides of nitrogen , manufacturers briefly installed twin catalyst systems, with an NO x reducing, rhodium/platinum catalyst ahead of
7884-617: The extent of early Egyptians' knowledge of the metal is unclear. It is quite possible they did not recognize there was platinum in their gold. The metal was used by Native Americans near modern-day Esmeraldas, Ecuador to produce artifacts of a white gold-platinum alloy. Archeologists usually associate the tradition of platinum-working in South America with the La Tolita Culture ( c. 600 BCE – 200 CE), but precise dates and location are difficult, as most platinum artifacts from
7992-533: The external location and the use of valuable precious metals including platinum , palladium and rhodium , catalytic converters are a target for thieves. The problem is especially common among late-model pickup trucks and truck-based SUVs , because of their high ground clearance and easily removed bolt-on catalytic converters. Welded-on converters are also at risk of theft, as they can be easily cut off. The Toyota Prius catalytic converters are also targets for thieves. The catalytic converters of hybrids need more of
8100-417: The gasoline additive MMT ), and silicon , which can enter the exhaust stream if the engine has a leak that allows coolant into the combustion chamber. Phosphorus is another catalyst contaminant. Although phosphorus is no longer used in gasoline, it (and zinc , another low-level catalyst contaminant) was widely used in engine oil antiwear additives such as zinc dithiophosphate (ZDDP). Beginning in 2004,
8208-411: The gold, the platinum is precipitated as ammonium chloroplatinate by the addition of ammonium chloride . Ammonium chloroplatinate can be converted to platinum by heating. Unprecipitated hexachloroplatinate(IV) may be reduced with elemental zinc , and a similar method is suitable for small scale recovery of platinum from laboratory residues. Mining and refining platinum has environmental impacts. Of
8316-416: The hot catalyst, burning in the catalyst and increasing its temperature. Unwanted reactions result in the formation of hydrogen sulfide and ammonia , which poison catalysts. Nickel or manganese is sometimes added to the washcoat to limit hydrogen-sulfide emissions. Sulfur-free or low-sulfur fuels eliminate or minimize problems with hydrogen sulfide. For compression-ignition (i.e., diesel ) engines,
8424-422: The length of a platinum-iridium (90:10) alloy bar, known as the 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. The Standard Platinum Resistance Thermometer (SPRT) is one of the four types of thermometers used to define
8532-602: The less common PtO both decompose upon heating. Platinum(II,IV) oxide, Pt 3 O 4 , is formed in the following reaction: Unlike palladium acetate , platinum(II) acetate is not commercially available. Where a base is desired, the halides have been used in conjunction with sodium acetate . The use of platinum(II) acetylacetonate has also been reported. Several barium platinides have been synthesized in which platinum exhibits negative oxidation states ranging from −1 to −2. These include BaPt, Ba 3 Pt 2 , and Ba 2 Pt . Caesium platinide, Cs 2 Pt ,
8640-447: The mixture in either of the two acids and recovering the remaining platinum. One suitable method for purification for the raw platinum, which contains platinum, gold, and the other platinum-group metals, is to process it with aqua regia , in which palladium, gold and platinum are dissolved, whereas osmium, iridium, ruthenium and rhodium stay unreacted. The gold is precipitated by the addition of iron(II) chloride and after filtering off
8748-596: The most commonly used catalytic converter is the diesel oxidation catalyst (DOC). DOCs contain palladium or platinum supported on alumina . This catalyst converts particulate matter (PM), hydrocarbons, and carbon monoxide to carbon dioxide and water. These converters often operate at 90 percent efficiency, virtually eliminating diesel odor and helping reduce visible particulates. These catalysts are ineffective for NO x , so NO x emissions from diesel engines are controlled by exhaust gas recirculation (EGR). In 2010, most light-duty diesel manufacturers in
8856-592: The ore, including gold, mercury, lead, copper, and iron. This led him to believe he was working with a single metal, but in truth the ore still contained the yet-undiscovered platinum-group metals. This led to inconsistent results in his experiments. At times, the platinum seemed malleable, but when it was alloyed with iridium, it would be much more brittle . Sometimes the metal was entirely incombustible, but when alloyed with osmium, it would volatilize. After several months, Chabaneau succeeded in producing 23 kilograms of pure, malleable platinum by hammering and compressing
8964-582: The oxidation reactions. An upstream air injection point, ahead of the catalytic converter, is also sometimes present to provide additional oxygen only during the engine warm up period. This causes unburned fuel to ignite in the exhaust tract, thereby preventing it reaching the catalytic converter at all. This technique reduces the engine runtime needed for the catalytic converter to reach its "light-off" or operating temperature . Most newer vehicles have electronic fuel injection systems, and do not require air injection systems in their exhausts. Instead, they provide
9072-538: The platinum alloy. Alloying this impure platinum residue called "plyoxen" with gold was the only solution at the time to obtain a pliable compound, but nowadays, very pure platinum is available and extremely long wires can be drawn from pure platinum, very easily, due to its crystalline structure, which is similar to that of many soft metals. In 1786, Charles III of Spain provided a library and laboratory to Pierre-François Chabaneau to aid in his research of platinum. Chabaneau succeeded in removing various impurities from
9180-468: The platinum-group metals as well as selenium and tellurium settle to the bottom of the cell as "anode mud", which forms the starting point for the extraction of the platinum-group metals. If pure platinum is found in placer deposits or other ores, it is isolated from them by various methods of subtracting impurities. Because platinum is significantly denser than many of its impurities, the lighter impurities can be removed by simply floating them away in
9288-404: The precious metals to work properly compared to conventional internal combustion vehicles because they do not get as hot as those installed on conventional vehicles, since the combustion engines of hybrids only run part of the time. Pipecutters are often used to quietly remove the converter but other tools such as a portable reciprocating saw can damage other components of the car, such as
9396-413: The price of platinum tends to be as much as twice the price of gold, whereas during periods of economic uncertainty, 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. Although gold is also used in industrial applications, especially in electronics due to its use as
9504-403: The reactions do not occur stepwise: All three reactions are reversible. Platinum(II) and platinum(IV) bromides are known as well. Platinum hexafluoride is a strong oxidizer capable of oxidizing oxygen . Platinum(IV) oxide , PtO 2 , also known as " Adams' catalyst ", is a black powder that is soluble in potassium hydroxide (KOH) solutions and concentrated acids. PtO 2 and
9612-414: The removal of the antiknock agent tetraethyl lead from automotive gasoline, to reduce lead in the air. Lead and its compounds are catalyst poisons and foul catalytic converters by coating the catalyst's surface. Requiring the removal of lead allowed the use of catalytic converters to meet the other emission standards in the regulations. To lower harmful NO x emissions, a twin-catalyst system
9720-417: The role of smokestack exhaust and automobile exhaust in air pollution and founded a company called Oxy-Catalyst. Houdry first developed catalytic converters for smokestacks , called "cats" for short, and later developed catalytic converters for warehouse forklifts that used low grade, unleaded gasoline. In the mid-1950s, he began research to develop catalytic converters for gasoline engines used on cars and
9828-474: The second (HC and CO oxidation) catalyst is sufficiently oxygen-saturated. Catalyst poisoning occurs when the catalytic converter is exposed to exhaust containing substances that coat the working surfaces, so that they cannot contact and react with the exhaust. The most notable contaminant is lead , so vehicles equipped with catalytic converters can run only on unleaded fuel. Other common catalyst poisons include sulfur , manganese (originating primarily from
9936-468: The sensing of the changed air–fuel ratio by the sensor, as well as the sigmoidal response of the oxygen sensors. Typical control systems are designed to rapidly sweep the air–fuel ratio such that it oscillates slightly around the stoichiometric point, staying near the optimal efficiency point while managing the levels of stored oxygen and unburnt HC. Closed loop control is often not used during high load/maximum power operation, when an increase in emissions
10044-418: The sensor, the air–fuel ratio is lean of stoichiometric, and when oxygen is not detected, it is rich. The control system adjusts the rate of fuel being injected into the engine based on this signal to keep the air–fuel ratio near the stoichiometric point in order to maximize the catalyst conversion efficiency. The control algorithm is also affected by the time delay between the adjustment of the fuel flow rate and
10152-496: The sponge form while white-hot. Chabeneau realized the infusibility of platinum would lend value to objects made of it, and so started a business with Joaquín Cabezas producing platinum ingots and utensils. This started what is known as the "platinum age" in Spain. Platinum, along with the rest of the platinum-group metals , is obtained commercially as a by-product from nickel and copper mining and processing. During electrorefining of copper , noble metals such as silver, gold and
10260-400: The stock catalytic converter netted only a 3% increase in maximum horsepower; a new metallic core converter only cost the car 1% horsepower, compared to no converter. Carburetors on pre-1981 vehicles without feedback fuel-air mixture control could easily provide too much fuel to the engine, which could cause the catalytic converter to overheat and potentially ignite flammable materials under
10368-442: The time therefore included secondary air injection , which injected air into the exhaust stream. This increased the available oxygen, allowing the catalyst to function as intended. Some three-way catalytic converter systems have air injection systems with the air injected between the first ( NO x reduction) and second (HC and CO oxidation) stages of the converter. As in two-way converters, this injected air provides oxygen for
10476-479: The total number of known isotopes 44. The least stable of these are Pt and Pt , with half-lives of 260 μs, whereas the most stable is Pt with a half-life of 50 years. Most platinum isotopes decay by some combination of beta decay and alpha decay. Pt , Pt , and Pt decay primarily by electron capture . Pt and Pt are predicted to have energetically favorable double beta decay paths. Platinum
10584-476: The upstream components of the exhaust system (manifold or header assembly and associated clamps susceptible to rust, corrosion or fatigue such as the exhaust manifold splintering after repeated heat cycling), ignition system (e.g., coil packs, primary ignition components, distributor cap, wires, ignition coil and spark plugs) or damaged fuel system components (e.g., fuel injectors, fuel pressure regulator, and associated sensors). Oil and coolant leaks, perhaps caused by
10692-527: The writings of the Italian humanist Julius Caesar Scaliger as a description of an unknown noble metal found between Darién and Mexico, "which no fire nor any Spanish artifice has yet been able to liquefy". From their first encounters with platinum, the Spanish generally saw the metal as a kind of impurity in gold, and it was treated as such. It was often simply thrown away, and there was an official decree forbidding
10800-445: Was 192,000 kg (423,000 lb). Large platinum deposits are present in the state of Tamil Nadu , India . Platinum exists in higher abundances on the Moon and in meteorites. Correspondingly, platinum is found in slightly higher abundances at sites of bolide impact on Earth that are associated with resulting post-impact volcanism, and can be mined economically; the Sudbury Basin
10908-422: Was awarded United States Patent 2,742,437 for his work. Catalytic converters were further developed by a series of engineers including Carl D. Keith , John J. Mooney , Antonio Eleazar, and Phillip Messina at Engelhard Corporation, creating the first production catalytic converter in 1973. The first widespread introduction of catalytic converters was in the United States automobile market. To comply with
11016-521: Was developed in the 1970s – this added a separate (rhodium/platinum) catalyst which reduced NO x ahead of the air pump, after which a two-way catalytic converter (palladium/platinum) removed HC and CO. This cumbersome and expensive system was soon made redundant, after it was noted that under some conditions the initial catalyst also removed HC and CO. This led to the development of the three-way catalyst, made possible by electronics and engine management developments. William C. Pfefferle developed
11124-1158: Was in the United States automobile market. To comply with the U.S. Environmental Protection Agency 's stricter regulation of exhaust emissions, most gasoline-powered vehicles starting with the 1975 model year are equipped with catalytic converters. These "two-way" converters combine oxygen with carbon monoxide (CO) and unburned hydrocarbons (HC) to produce carbon dioxide (CO 2 ) and water (H 2 O). Although two-way converters on gasoline engines were rendered obsolete in 1981 by "three-way" converters that also reduce oxides of nitrogen ( NO x ), they are still used on lean-burn engines to oxidize particulate matter and hydrocarbon emissions (including diesel engines, which typically use lean combustion), as three-way-converters require fuel-rich or stoichiometric combustion to successfully reduce NO x . Although catalytic converters are most commonly applied to exhaust systems in automobiles, they are also used on electrical generators , forklifts , mining equipment, trucks , buses , locomotives , motorcycles , and on ships. They are even used on some wood stoves to control emissions. This
11232-457: Was referenced in European writings as early as the 16th century, but it was not until Antonio de Ulloa published a report on a new metal of Colombian origin in 1748 that it began to be investigated by scientists. Platinum is used in catalytic converters , laboratory equipment, electrical contacts and electrodes , platinum resistance thermometers , dentistry equipment, and jewelry. Platinum
11340-512: Was the first in the list), Scheffer and Sickingen made the false assumption that due to its hardness—which is slightly more than for pure iron —platinum would be a relatively non-pliable material, even brittle at times, when in fact its ductility and malleability are close to that of gold. Their assumptions could not be avoided because the platinum they experimented with was highly contaminated with minute amounts of platinum-family elements such as osmium and iridium , amongst others, which embrittled
11448-496: Was the first to systematically study platinum, which was in 1748. His historical account of the expedition included a description of platinum as being neither separable nor calcinable . Ulloa also anticipated the discovery of platinum mines. After publishing the report in 1748, Ulloa did not continue to investigate the new metal. In 1758, he was sent to superintend mercury mining operations in Huancavelica . In 1741, Charles Wood ,
11556-570: Was upgraded with a six-speed transmission, together with the introduction of the Yamaha Computerized Lubrication System or YCLS, as well as a new front cowl and new a gauge cluster. The third generation RX-Z came out in 2004 when the model was updated, with the rear lights borrowed from the Yamaha Y125Z and is equipped a catalytic converter due to Euro 3 regulations and production was only up until 2011. In Malaysia,
11664-536: Was used in Alpina's B12 5,7 E-KAT based on the BMW 750i . Heating coils inside the catalytic converter assemblies are electrified just after the engine is started, bringing the catalyst up to operating temperature very quickly to qualify the vehicle for low emission vehicle (LEV) designation. BMW later introduced the same heated catalyst, developed jointly by Emitec, Alpina, and BMW, in its 750i in 1999. Some vehicles contain
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