Platinum group metals (PGMs) consist of six metals namely platinum (Pt), palladium (Pd), Ruthenium (Ru), rhenium (Re), rhodium (Rh), iridium (Ir) and osmium (Os). They belong in the transition metals group of the periodic table with excellent properties such as high melting point and are inert with a variety of substances, thus also called noble metals. Pt and Pd have the greatest economic importance and are produced in large quantities for autocatalysis, jewellery, electronics and chemical industries. Production of Rh, Ru, Ir and Os is comparatively less and only produced as by-products during the refinery of Pt and Pd.

Os is rarely used and has found limited application in the industry due to the extreme toxicity of the volatile osmium tetroxide (OsO₄). However, over the years researchers have developed an interest in Os and have found ways to synthesise Os compounds safely by manipulating high vacuum methods along with high pressure-high temperature techniques for solid state compounds. These include synthesis of Os oxides and Os carbides using high pressure-high temperature apparatus. Some researchers have found a niche in the area of drug discovery. Different Os complexes have been synthesised for the use in anti-cancer drugs research. Furthermore, Os (II) complexes have found the niche in sensor and actuator applications. Theoretical desktop studies have been used in order to limit the human exposure to OsO₄ and the characterisation of Os complexes for chemical and electrochemical properties have been possible. The available literature indicates that Os compounds have excellent electrochemical properties and has rendered Os compounds as “smart compounds”. Osmium and its compounds possess a variety of correlated properties with a potential to put an emergent demand on Os for various applications. Taking into advantage the octavalent nature of Os, there are more areas of research worthy of special attention.

The purpose of this issue is to present recent advances in osmium-based research from both chemical and materials perspectives, considering the production techniques and technology, and Os material functionality. The scope is wide open for publication of osmium-based research in the fields of electrochemical engineering (Redox flow batteries and actuators), Materials engineering (Hard materials, alloys for extreme environments), photovoltaic materials (Os oxides, including perovskites), biomedical engineering (Drug discovery) and computational modelling.