Enhanced Hydrogen Dissociation by Individual Co Atoms Supported on Ag(111)

By means of scanning tunneling microscopy, individual Co atoms adsorbed on Ag(111) are found to behave as a model catalyst for the hydrogen oxidation reaction. The dosing of H₂ in a cryogenic environment produces the otherwise unstable CoH₃ molecule, which results in the complete suppression of the Kondo resonance of the host Co atom. Short voltage pulses over Co hydrides permit reversible dehydrogenation and so, the identification of the intermediate compounds. The electric polarizability of CoH₃ allows controlling molecular diffusion via an external electric field, from the range of tens of nm down to the assembly of larger hydride complexes at the molecular scale