A Catalyst That Is Cheaper Than Platinum

In the continuing search for cheaper, more efficient catalysts for cleansing diesel engine exhaust, researchers report a new class of mixed-phase oxides that under laboratory conditions exceed the performance of expensive commercial platinum-based catalysts.

A team of scientists from the U.S., China, and South Korea, led by materials scientists Kyeongjae Cho and Xianghong Hao at Nanostellar Inc. in Redwood City, Calif., report that Mn-mullite(Sm, Gd)Mn2O5—manganese-mullite materials containing either samarium or gadolinium—converts the toxic diesel engine exhaust product nitric oxide to the more benign nitrous oxide.

Researchers have put a lot of effort into the search for metal-oxide catalysts. For example, scientists reported the development of a strontium-doped perovskite oxide catalyst that outperforms platinum catalysts. However, various factors, including lack of thermal stability, have bedeviled efforts to industrialize them.

James E. Parks II, who leads an emissions and catalysis research group at Oak Ridge National Laboratory, says the work “shows the benefits of using theoretical simulations to better understand the catalytic processes occurring on new materials.”

Chang H. Kim of General Motors Global R&D, whose team developed the perovskite catalyst, notes the new catalyst’s good NO-to-NO2 conversion abilities but cautions that like other potential catalysts, this material will have to withstand the rigors of real-world conditions.

The researchers investigated the catalyst’s mechanism using infrared Fourier transform spectroscopy as well as density functional theory calculations. They found that its catalytic activity is localized at Mn–Mn (Manganese) dimers on the rough, defect-riddled, or “stepped” mullite (its CAS number is 1302-93-8 )surface.

Yasutake Teraoka, a materials science professor at Japan’s Kyushu University, praised the research. “The development of nonplatinum catalysts for NO oxidation is very challenging,” he says. Parks also points out that the catalyst might find use in so-called lean-burn engines, which use much less fuel than traditional internal combustion engines. Emissions control systems in these engines are costly and limit their commercialization, he says. The new work, he notes, “may provide a solution for cost-effective lean gasoline emission control.”

Significance Of Manganese In Industry And Body

The chemical element of manganese is designated with a chemical symbol of Mn and has an atomic number of 25. Here are some basic facts about this chemical, its uses and examples of how the element is a vital component in everything from steel production to the health of the human body.

For Health
In human body, the use of manganese as an essential trace mineral that is considered to be both a brain and a nerve food. The mineral is considered to be essential for the formation of healthy red blood cells, proper pituitary gland function, and the maintenance of good eyesight. Many herbal supplements that are meant to combat mental and physical fatigue, digestion problems, and nervous conditions will contain herbs such as ginger and catnip, both known to contain significant amounts of the mineral. It is safe to say that Mn is an essential part of our lives in more ways than one.

One of the more noticeable manganese deficiency symptoms has to do with the proper healing of wounds such as cuts and scratches. Since the mineral aids in the creation of collagen, the deficiency will make it more difficult for the natural healing process to take place. Women may experience problems with the menstrual cycle as a result of a deficien0cy. The cycle may become erratic in both timing and the severity of the cycle itself.

The most significant of all the industrial uses of manganese is steel production which uses more than 85% of all this mined. It can be used in several different alloying processes to improve the durability of steel. The ore is particularly useful in increasing steel’s resistance to oxidation, so the mineral is often used to make stainless steel. The addition of it to steel can also improve the overall strength and workability of the material. Hadfield Steel is one example of a mixture of steel and Mn, and is known for both these properties.

A number of other uses are common today. Fore example, the inclusion of manganese(CAS:7439-96-5) in gasoline additives has been shown to boost octane ratings and helps to minimize engine knocking. In glass making, it helps to remove the green tinge that is something left by the presence of iron particles. Its phosphates help to deal with rust and corrosion on steel surfaces. Its oxide has a brown appearance that can be used in paints.

The element is also used sparingly in the manufacture of coins in various countries. Current, the European Union uses manganese to produce one- and two- Euro coins, while in the United States, the one dollar coin contains high levels of Mn.