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For compression-ignition (i.e., diesel) engines, 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 ...
Subsequent changes in the relative price of platinum lowered demand for palladium to 17.4 tonnes in 2009. [70] [71] Demand for palladium as a catalyst has increased the price of palladium to about 50% higher than that of platinum in January 2019. [72]
Palladium on carbon is a common catalyst for hydrogenolysis. Such reactions are helpful in deprotection strategies. Particularly common substrates for hydrogenolysis are benzyl ethers: [5] Other labile substituents are also susceptible to cleavage by this reagent. [6]
All the noble metals can act as catalysts. For example, platinum is used in catalytic converters, devices which convert toxic gases produced in car engines, such as the oxides of nitrogen, into non-polluting substances. [citation needed] Gold has many industrial applications; it is used as a catalyst in hydrogenation and the water gas shift ...
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 "silver". [7] [8] Platinum is a member of the platinum group of elements and group 10 of the periodic table of ...
Hydrogenation is a chemical reaction between molecular hydrogen (H 2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds .
The catalyst is also used for the hydrogenolysis of phenyl phosphate esters, a reaction that does not occur with palladium catalysts. The pH of the solvent significantly affects the reaction course, and reactions of the catalyst are often enhanced by conducting the reduction in neat acetic acid, or solutions of acetic acid in other solvents.
Palladium catalysts can be problematic for the pharmaceutical industry, which faces extensive regulation regarding heavy metals. Many pharmaceutical chemists attempt to use coupling reactions early in production to minimize metal traces in the product. [8] Heterogeneous catalysts based on Pd are also well developed. [9]