Cover Picture: Efficient Catalytic Decomposition of Formic Acid for the Selective Generation of H2 and H/D Exchange with a Water‐Soluble Rhodium Complex in Aqueous Solution (ChemSusChem 10/2008)

Abstract

The cover picture shows a scheme for the efficient rhodium-catalyzed evolution of H2 or D2 from formic acid (HCOOH), a substance produced naturally by ants. The use of hydrogen as an environmentally benign secondary energy resource has attracted much attention, however, high-density storage and safe transportation of gaseous hydrogen remain problematic. An approach that can contribute also to cut carbon dioxide emissions is the use of CO2 as hydrogen carrier to produce formic acid, a water-soluble liquid which is easy to store and carry. In their Full Paper on page 827 ff., S. Fukuzumi et al. describe how HCOOH is efficiently and selectively decomposed to produce H2 and CO2 in 1:1 ratio without the formation of CO in aqueous solution at 298 K catalyzed by the water-soluble rhodium aqua complex [RhIII(Cp*)(bpy)(H2O)]SO4. H2 evolution occurs by formation of the hydride complex (RhH), which undergoes efficient H/D exchange with deuteron in D2O to form the deuteride complex (RhD) in competition with the reaction with deuteron to yield D2 and HD.