Monometallic Cobalt–Trisglyoximato Complexes as Precatalysts for Catalytic H₂ Evolution in Water

Electrochemical investigation on differently substituted boron-caped and glyoximato-strapped ligands of cobalt clathrochelate complexes in the presence of acid revealed the formation of cobalt-based nanoparticles at the surface of the electrode. The potential for the electrochemical deposition is a function of the chemical nature of the substituents. The overpotential for the catalytic proton reduction of the resulting cobalt particles at pH 7 was found to be ∼700 mV less negative than on the bare carbon electrode for a geometric current density of 5 mA/cm<sup>2