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What is Ruthenium?

Ruthenium is described as a chemical element having the symbol Ru and with an atomic number 44. This metal is a rare transition one that belongs to the platinum group of the periodic table. Similar to other metals of the platinum group, Ruthenium is said to be inert to most other chemicals. In 1844, Karl Ernst Claus, who is a Russian-born scientist of Baltic-German ancestry had discovered this element at Kazan State University and was named Ruthenium in honour of Russia. In 2017, the annual production of Ruthenium has risen from about 19 tonnes in 2009 up to 35.5 tonnes.

Properties of Ruthenium

  • In the periodic table, Ruthenium is a member of the platinum group.

  • Whereas in the environment, it can be found as a free metal, or it can be found occasionally as a chemical combination with osmium, iridium, and platinum ores. At times, it is also associated with the deposits of nickel.

Let us look at some important properties of Ruthenium

Important Properties of Ruthenium



Atomic Mass

101.1 g.mol-1

Atomic Number


Discovered by

Karl Klaus - In 1844

Chemical Properties of Ruthenium







Atomic Number


Electron configuration

[Kr] 4d75s1

State at 20°C


ChemSpider ID


Melting point

2250 °C

Boiling Point

4150 °C

Relative atomic mass


Density (g cm−3)


CAS number


Key isotopes

101Ru, 102Ru, 104Ru

Characteristics of Ruthenium

Ruthenium contains four crystal modifications, and it does not tarnish at ambient conditions; it also oxidizes upon heating to 800 °C (1,070 K). This metal dissolves in fused alkalis to produce ruthenates (RuO2−4), which is not attacked by the acids (even te aqua regia), but it is attacked by halogens at high temperatures. Indeed, the ruthenium metal is more readily attacked by oxidizing agents. The small amounts of ruthenium increase the palladium and platinum hardness. The titanium’s corrosion resistance is markedly increased due to the addition of a less quantity of Ruthenium.

This metal is plated by thermal decomposition and electroplating. A ruthenium-molybdenum alloy is referred to be superconductive at temperatures below 10.6 K. Ruthenium is one and only 4d transition metal that can assume the group oxidation state of +8, and even it is less stable there compared to the heavier congener osmium. This is said as the first group from the left side of the table, where the second and third-row of the transition metals represent notable differences in their chemical behaviour. Similar to iron but dissimilar to osmium, Ruthenium can produce aqueous cations in its lower oxidation states of +2 and +3.


Being the 74th most abundant element in the crust of Earth, ruthenium metal is relatively rare, which is found in about 100 parts per trillion. Generally, this element can be found in ores with the other platinum group metals present in North and South America and in the Ural Mountains. Less, but commercially important amounts are also present in pentlandite mined from Ontario, Sudbury, Canada, and pyroxenite deposits in South Africa. Ruthenium’s native form is a very rare mineral (where Ir replaces part of Ru in its structure).


Around 30 tonnes of Ruthenium are mined every year, with world reserves at an estimation of  5,000 tonnes. The composition of the mined Platinum Group Metal (PGM) mixtures widely changes, based on the geochemical formation. For suppose, the PGMs which are mined in South Africa contain on average of 11 percent of Ruthenium while the PGMs which are mined in the former USSR contain only 2 percent (as of 1992). Osmium, iridium, and Ruthenium are considered to be the minor platinum group metals.

Applications of Ruthenium

Let us look at some of the applications that are related to Ruthenium.

Nearly 30.9 tonnes of Ruthenium were consumed as of 2016, whereas 7.7 in catalysis, 13.8 of them in electrical applications, and 4.6 in electrochemistry.

Because it hardens the alloys of palladium and platinum, Ruthenium can be used in the electrical contacts, where a thin film is enough to achieve the wanted durability. With the same properties and lower cost compared to the rhodium, electric contacts are a primary use of Ruthenium. The ruthenium plate can be applied to the electrode base metal and electrical contact by sputtering or electroplating.

Ruthenium dioxide with bismuth ruthenates and lead are used in the thick-film chip resistors. These both electronic applications account for 50 percent of the consumption of Ruthenium.

Ruthenium is seldom alloyed with metals outside of the platinum group, where the small quantities improve a few properties. The added corrosion resistance present in the titanium alloys led to the special alloy development with 0.1 percent of Ruthenium. Ruthenium can also be used in a few advanced high-temperature single-crystal superalloys, including the applications such as the turbines in jet engines.

Uses of Ruthenium

  • Ruthenium is used in the manufacturing of electronic devices and low-cost solar cells.

  • It also acts as a versatile catalyst in the synthesis of Fischer Tropsch and olefin metathesis.

  • It can be used as exotic materials.

FAQ (Frequently Asked Questions)

1. Explain the catalysis of Ruthenium.

Most of the ruthenium-containing compounds show useful catalytic properties. Conveniently, the catalysts are divided into those which are soluble in the homogeneous catalysts, reaction medium, and those that are not, are called heterogeneous catalysts.

Ruthenium nanoparticles are formed inside the halloysite. This abundant mineral naturally contains a structure of rolled nanosheets (otherwise called nanotubes), which can support both the synthesis of Ru nanocluster and its products for subsequent usage in industrial catalysis.

2. List the emerging applications of Ruthenium.

A few of the ruthenium complexes absorb light throughout the visible spectrum, and they are actively researched for the technologies of solar energy. Suppose the compounds based on Ruthenium have been used for light absorption in the solar cells of dye-sensitized, which is a promising new and low-cost solar cell system.

Several oxides that are based on ruthenium exhibits very unusual properties, like exotic superconductivity (in its form of strontium ruthenate), a quantum critical point behaviour, and high-temperature ferromagnetism.

3. Give the health effects of Ruthenium.

A little is known about the health effects of Ruthenium, and it is relatively rare for people to encounter the compounds of Ruthenium. The metallic Ruthenium is inert (which is not chemically reactive). A few compounds, like ruthenium oxide (RuO4), are volatile and highly toxic.

4. Where does the Ruthenium-promoted cobalt catalysts use?

The ruthenium-promoted cobalt catalysts can be used in the synthesis of Fischer-Tropsch.