The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the beta-carbon of the alkene with formation of a delta-bond…

Potassium dioxide, KO[subscript 2], (potassium superoxide) is an important compound owing to its ability to react with carbon dioxide to produce oxygen. This unique ability is employed to design rebreathing devices for submarines, space vehicles, and space suits. "Rebreathers" for firefighters and miners have also been designed using potassium…