Molybdenum is an essential trace element for virtually all life forms. In industry, it ia applied in many vital fields. In human body, it functions as a cofactor for a number of enzymes that catalyze important chemical transformations in the global carbon, nitrogen, and sulfur cycles.
Discovered in 1778 by Swedish Chemist Carl Wilhelm Scheele and isolated in 1781 by Peter Jacob Hjelm, molybdenum is used mainly as a component of alloyed steel. Because of its softness, color, and greasy feel, it was originally mistaken as a lead compound. A silvery white metal with an atomic number of 42, it is solid at room temperature, has an atomic mass of 95.94, and appears in the periodic table of elements under the chemical symbol of “Mo.” In fact, compared to other pure elements, it has one of the highest melting points. One most unique and therefore useful qualities is its extremely high melting point: 4753 degrees F (2623 degrees C, or 2896 K).
The most significant of the uses is as an additive in steel and iron alloys. Because of its ability to withstand extremely high temperatures, it is used in the manufacture of missiles, aircrafts, spacecrafts, rifle barrels, light bulb filaments, and furnace components. In the early 21st century, about half of all mined molybdenum was used for iron and steel alloys in construction, tools, auto parts and steam turbines.
One of the important energy-related uses of molybdenum is as a catalyst in the refining of fuel. It can be used as a chemical catalyst. Its versatile chemical structure and the ease with which it transitions between oxidation states makes it an attractive catalyst for scientists creating chemical reactions and syntheses in laboratories.
The chemical can be mined directly, gleaned from ore sources such as molybdenite or molybdenum sulfide (MoS2), obtained as a by-product of copper mining, and recovered from the mineral wulfenite (PbMoO4). Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. The United States is a significant source of Mo in the world, drawing from mines in Colorado, New Mexico, and Idaho. Other prolific producers worldwide include China, Canada, Peru, and Russia.
As an essential trace element in plants, animals and humans, the element plays an important role in the conversion of atmospheric nitrogen to ammonia. That fact makes the use in fertilizers a common occurrence. Trace amounts of dietary molybdenum is also necessary to promote growth in animals; excessive amounts however is toxic.