Co-Ag alloy protected by nitrogen doped carbon as highly efficient and chemoselective catalysts for the hydrogenation of halogenated nitrobenzenes.

See more Cobalt products. Cobalt (atomic symbol: Co, atomic number: 27) is a Block D, Group 9, Period 4 element with an atomic weight of 58.933195. The number of electrons in each of cobalt's shells is 2, 8, 15, 2 and its electron configuration is [Ar]3d⁷ 4s². The cobalt atom has a radius of 125 pm and a Van der Waals radius of 192 pm. Cobalt was first discovered by George Brandt in 1732. In its elemental form, cobalt has a lustrous gray appearance. Cobalt is found in cobaltite, erythrite, glaucodot and skutterudite ores. Cobalt produces brilliant blue pigments which have been used since ancient times to color paint and glass. Cobalt is a ferromagnetic metal and is used primarily in the production of magnetic and high-strength superalloys. Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. The origin of the word Cobalt comes from the German word "Kobalt" or "Kobold," which translates as "goblin," "elf" or "evil spirit.

See more Silver products. Silver (atomic symbol: Ag, atomic number: 47) is a Block D, Group 11, Period 5 element with an atomic weight of 107.8682. The number of electrons in each of Silver's shells is 2, 8, 18, 18, 1 and its electron configuration is [Kr]4d¹⁰ 5s¹. The silver atom has a radius of 144 pm and a Van der Waals radius of 203 pm. Silver was first discovered by Early Man prior to 5000 BC. In its elemental form, silver has a brilliant white metallic luster. It is a little harder than gold and is very ductile and malleable, being exceeded only by gold and perhaps palladium. Pure silver has the highest electrical and thermal conductivity of all metals and possesses the lowest contact resistance. It is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide, or air containing sulfur. It is found in copper, copper-nickel, lead, and lead-zinc ores, among others. Silver was named after the Anglo-Saxon word "seolfor" or "siolfur," meaning 'silver'.

See more Nitrogen products. Nitrogen is a Block P, Group 15, Period 2 element. Its electron configuration is [He]2s²2p³. Nitrogen is an odorless, tasteless, colorless and mostly inert gas. It is the seventh most abundant element in the universe and it constitutes 78.09% (by volume) of Earth's atmosphere. Nitrogen was discovered by Daniel Rutherford in 1772.