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Catalyst poisoning is the partial or total deactivation of a catalyst by a chemical compound. Poisoning refers specifically to chemical deactivation, rather than other mechanisms of catalyst degradation such as thermal decomposition or physical damage. [1] [2] Although usually undesirable, poisoning may be helpful when it results in improved ...
2), in the case of urea use, are produced. Selective catalytic reduction of NO x using ammonia as the reducing agent was patented in the United States by the Engelhard Corporation in 1957. Development of SCR technology continued in Japan and the US in the early 1960s with research focusing on less expensive and more durable catalyst agents.
The majority of hydrogen peroxide solutions are 3% hydrogen peroxide. [1] This enables the solution to break down any proteins that coat the contacts after a long period of use. Hydrogen peroxide is always used alongside a neutralizing product. [2] The intention is to prevent the hydrogen peroxide from contact with the eye, which could damage ...
The monolith is a substrate that supports a catalyst. After the monolith is complete, a washcoat is applied that deposits oxides and catalyst (s) (most commonly platinum, palladium, and/or rhodium) on the walls of the holes. Alternative structures include corrugated metal and a packed bed of coated pellets or other shapes.
Carbonyl reduction. Oxidation ladders such as this one are used to illustrate sequences of carbonyls which can be interconverted through oxidations or reductions. In organic chemistry, carbonyl reduction is the conversion of any carbonyl group, usually to an alcohol. It is a common transformation that is practiced in many ways. [1]
Catalytic converter. A catalytic converter 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 ...
Appearance. Selective non-catalytic reduction ( SNCR) is a method to lessen nitrogen oxide emissions in conventional power plants that burn biomass, waste and coal. The process involves injecting either ammonia or urea into the firebox of the boiler at a location where the flue gas is between 1,400 and 2,000 °F (760 and 1,090 °C) to react ...
Contact process. For the stochastic process used to model population, see Contact process (mathematics). The contact process is the current method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, as it is susceptible to reacting with ...