显示标签为“Molybdenum Disulfide”的博文。显示所有博文
显示标签为“Molybdenum Disulfide”的博文。显示所有博文

2013年9月25日星期三

Molybdenum Applications

Molybdenum is a silvery grey metal that is not found in a pure state in nature. It is usually associated with other elements, such as is the case of sulfurated ores, from which one can also obtain copper. Thus it is common for molybdenum to be regarded as a byproduct of the copper extraction operation.

In the periodic table of chemical elements, molybdenum is identified with number 42 and the symbol Mo. It melts at a temperature of 2,610 degrees Celsius.
Its name originates from the Greek word, “molybdos”, meaning “lead-like”, in a clear allusion to its color. Although some say that it was known in ancient times, it was only during the World War I that its use in steel alloys was made known. Molybdenum was utilized instead of wolfram (aka tungsten) that in those times was scarce, and so began its commercial application.
Black Molybdenum Wire
Molybdenum Electrode
Molybdenum Apply In Plane
Molybdenum Disilicide Rod
Its main characteristics are durability, strength and resistance to corrosion and high temperatures.

Molybdenum is a metal used as raw material in order to obtain alloys, among which more resistant steel stands out. Approximately two thirds of this metal is used for this purpose, also known as inox, with contents up to 6%.

The steel alloy withstands high temperatures and pressures, being very resistant. This is why it is used in construction, to manufacture airplane parts and wrought car parts. Molybdenum wires are utilized in electronic tubes and the metal also functions as electrode in glass furnaces.
Among its many applications is a super-alloy that can be obtained from a nickel base, to produce catalysts which are used to eliminate sulfur in the oil industry.

In addition, it is utilized in the industrial process of lubricants (molybdenum disulfide is resistant to high temperatures, reduces wear and friction of motor parts – as may be the case of vehicle brakes), in the manufacture of linings and solvents, in the chemical industry (pigments for plastics, paints and rubber compounds) and in the electronic industry (electric conductors).

Molybdenum is also deemed to be a strategic material and has multiple applications in the aerospace and automobile industries, for surgical tools, as well as for manufacturing light bulbs (filament) and LCD screens, for water treatment and even for applying laser beams.

2013年7月24日星期三

Molybdenum Catalysts



Molybdenum Catalysts Structure
Molybdenum-based catalysts have a number of important applications in the petroleum and plastics industries. A major use is in the hydrodesulfurisation (HDS) of petroleum, petrochemicals and coal-derived liquids. The catalyst comprises MoS2 supported on alumina and promoted by cobalt or nickel and is prepared by sullfiding cobalt and molybdenum oxides on alumina. 

As the world supply of crude oil is further extended and low-sulfur crudes become less available, Molybdenum-based catalysts will increase in use. Molybdenum not only allows for economical fuel refining but also contributes to a safer environment through lower sulfur emissions.

Molybdenum catalysts are resistant to poisoning by sulfur and, for example, catalyse conversion of hydrogen and carbon monoxide from the pyrolysis of waste materials to alcohols in the presence of sulfur, under conditions that would poison precious metal catalysts. Similarly Mo-based catalysts have been used in the conversion of coal to hydrocarbon liquids.


 Molybdenum Disulfide Catalyst SEM

As a component of the bismuth molybdate selective oxidation catalyst molybdenum participates in the selective oxidation of, for example, propene, ammonia, and air to acrylonitrile, acetonitrile and other chemicals which are raw materials for the plastics and fibre industries. Similarly molybdenum in iron molybdate catalyses the selective oxidation of methanol to formaldehyde. 


Cobalt / Nickel-Molybdenum Hydrotreating Catalyst
Cobalt-Molybdenum Hydrotreating Catalyst To Convert Organic Sulfur