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Palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, groundwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum Group
The platinum-group metals (abbreviated as the PGMs; alternatively, the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs)) are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 and 6). The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum. They have similar physical and chemical properties, and tend to occur together in the same mineral deposits. However, they can be further subdivided into the iridium-group platinum-group elements (IPGEs: Os, Ir, Ru) and the palladium-group platinum-group elements (PPGEs: Rh, Pt, Pd) based on their behaviour in geological systems. The three elements above the platinum group in the periodic table (iron, nickel and cobalt) are all ferromagnetic; these, including the lanthanide element gadolinium, are the only known tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Hyde Wollaston
William Hyde Wollaston (; 6 August 1766 – 22 December 1828) was an English chemist and physicist who is famous for discovering the chemical elements palladium and rhodium. He also developed a way to process platinum ore into malleable ingots.Melvyn C. UsselmanWilliam Hyde WollastonEncyclopædia Britannica, retrieved 31 March 2013 Life He was born in East Dereham in Norfolk, the son of the Francis Wollaston (1737–1815), a noted amateur astronomer, and his wife Althea Hyde. He was one of 17 children, but the family was financially well-off and he enjoyed an intellectually stimulating environment. He was educated privately (and remotely) at Charterhouse School from 1774 to 1778 then studied Sciences at Gonville and Caius College, Cambridge. In 1793 he obtained his doctorate (MD) in medicine from Cambridge University, and was a Fellow of his college from 1787 to 1828. He worked as a physician in Huntingdon from 1789 then moved to Bury St Edmunds before moving to London ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Athena
Athena or Athene, often given the epithet Pallas, is an ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretized with the Roman goddess Minerva. Athena was regarded as the patron and protectress of various cities across Greece, particularly the city of Athens, from which she most likely received her name. The Parthenon on the Acropolis of Athens is dedicated to her. Her major symbols include owls, olive trees, snakes, and the Gorgoneion. In art, she is generally depicted wearing a helmet and holding a spear. From her origin as an Aegean palace goddess, Athena was closely associated with the city. She was known as ''Polias'' and ''Poliouchos'' (both derived from ''polis'', meaning "city-state"), and her temples were usually located atop the fortified acropolis in the central part of the city. The Parthenon on the Athenian Acropolis is dedicated to her, along with numerous other temples and monuments. As the patron of craft and weav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbol (chemistry)
Chemical symbols are the abbreviations used in chemistry for chemical elements, functional groups and chemical compounds. Element symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised. History Earlier symbols for chemical elements stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for lead (''plumbum'' in Latin); Hg is the symbol for mercury (''hydrargyrum'' in Greek); and He is the symbol for helium (a new Latin name) because helium was not known in ancient Roman times. Some symbols come from other sources, like W for tungsten (''Wolfram'' in German) which was not known in Roman times. A three-letter temporary symbol may be assigned to a newly synthesized (or not yet synthesized) element. For example, "Uno" was the temporary symbol fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bushveld Igneous Complex
The Bushveld Igneous Complex (BIC) is the largest layered igneous intrusion within the Earth's crust. It has been tilted and eroded forming the outcrops around what appears to be the edge of a great geological basin: the Transvaal Basin. It is approximately 2 billion years old and is divided into four different limbs: the northern, southern, eastern, and western limbs. The Bushveld Complex comprises the Rustenburg Layered suite, the Lebowa Granites and the Rooiberg Felsics, that are overlain by the Karoo sediments. The site was first discovered around 1897 by Gustaaf Molengraaff. Located in South Africa, the BIC contains some of the richest ore deposits on Earth. The complex contains the world's largest reserves of platinum-group metals (PGMs) or platinum group elements (PGEs)—platinum, palladium, osmium, iridium, rhodium, and ruthenium along with vast quantities of iron, tin, chromium, titanium and vanadium. These are used in, but not limited to, jewellery, automobiles and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodium
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is a very rare, silvery-white, hard, corrosion-resistant transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope: 103Rh. Naturally occurring rhodium is usually found as a free metal or as an alloy with similar metals and rarely as a chemical compound in minerals such as bowieite and rhodplumsite. It is one of the rarest and most valuable precious metals. Rhodium is found in platinum or nickel ores with the other members of the platinum group metals. It was discovered in 1803 by William Hyde Wollaston in one such ore, and named for the rose color of one of its chlorine compounds. The element's major use (consuming about 80% of world rhodium production) is as one of the catalysts in the three-way catalytic converters in automobiles. Because rhodium metal is inert against corrosion and most aggressive chemicals, and because of its rarity, rhodium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2 Pallas
Pallas (minor-planet designation: 2 Pallas) is the second asteroid to have been discovered, after Ceres. It is believed to have a mineral composition similar to carbonaceous chondrite meteorites, like Ceres, though significantly less hydrated than Ceres. It is the third-largest asteroid in the Solar System by both volume and mass, and is a likely remnant protoplanet. It is 79% the mass of Vesta and 22% the mass of Ceres, constituting an estimated 7% of the mass of the asteroid belt. Its estimated volume is equivalent to a sphere in diameter, 90–95% the volume of Vesta. During the planetary formation era of the Solar System, objects grew in size through an accretion process to approximately the size of Pallas. Most of these protoplanets were incorporated into the growth of larger bodies, which became the planets, whereas others were ejected by the planets or destroyed in collisions with each other. Pallas, Vesta and Ceres appear to be the only intact bodies from this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pallas (daughter Of Triton)
In Greek mythology, Pallas (; Ancient Greek: Παλλάς) was the daughter of Triton (son of Poseidon) and messenger of the seas. Mythology After Athena was born fully armed from Zeus' forehead, Triton, acting as a foster parent to the goddess, raised her alongside his own daughter, Pallas. The sea god taught both girls the arts of war. During an athletics festival, Pallas and Athena fought with spears in a friendly mock battle in which the victor would be whoever managed to disarm her opponent. At the beginning of the fight, Athena got the upper hand, until Pallas took over. Before she could win, Zeus, who was in attendance, fearing to see his own daughter lose, distracted Pallas with the Aegis, which she had once shown interest in. Pallas, stunned in awe, stood still as Athena, expecting her to dodge, impaled her accidentally. Out of sadness and regret, she created the palladium, a statue in the likeness of Pallas, and wrapped the aegis, which she had feared, about the bre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of 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 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. Consequent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Purification
A hydrogen purifier is a device to purify hydrogen if hydrogen production is done from hydrocarbon sources, the ultra-high purified hydrogen is needed for applications like PEM fuel cells . Palladium membrane hydrogen purifiers The palladium membrane is typically a metallic tube of a palladium and silver alloy material possessing the unique property of allowing only monatomic hydrogen to pass through its crystal lattice when it is heated above 300°C. Dense thin-metal membrane purifier Dense thin-metal membrane purifiers are compact, relatively inexpensive and simple to use. Pressure swing adsorption Pressure swing adsorption is used for the removal of carbon dioxide (CO2) as the final step in the large-scale commercial synthesis of hydrogen. It can also remove methane, carbon monoxide, nitrogen, moisture and in some cases, argon, from hydrogen. Catalytic recombination or deoxygenation purifier Catalytic recombination or deoxygenation is used to remove oxygen (O2) impurities. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalytic Converter
A catalytic converter is an exhaust emission control device that 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 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 (CO2) and water (H2O). Although two-way converters on gasoline engines were rendered obsolete in 1981 by "three-way" converters that also reduce oxides of nitrogen (); they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by any chemical reaction. The number of protons in the nucleus is the defining property of an element, and is referred to as its atomic number (represented by the symbol ''Z'') – all atoms with the same atomic number are atoms of the same element. Almost all of the baryonic matter of the universe is composed of chemical elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a minority of elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is primarily a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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