ja2096514_si_001.pdf (124.92 kB)
Electrocatalytic Hydrogen Redox Chemistry on Gold Nanoparticles
journal contribution
posted on 2012-02-22, 00:00 authored by Mathias Brust, Gabriel J. GordilloElectrocatalytic proton reduction leading to the formation
of adsorbed
molecular hydrogen on gold nanoparticles of 1–3 and 14–16
nm diameter stabilized by 1-mercapto-undecane-11-tetra(ethyleneglycol)
has been demonstrated by cyclic voltammetry using a hanging mercury
drop electrode. The nanoparticles were adsorbed to the electrode from
aqueous dispersion and formed robust surface layers transferrable
to fresh base electrolyte solutions. Unique electrocatalytic proton
redox chemistry was observed that has no comparable counterpart in
the electrochemistry of bulk gold electrodes. Depending on size, the
nanoparticles have a discrete number of electrocatalytically active
sites for the two-electron/two-proton reduction process. The adsorbed
hydrogen formed is oxidized with the reverse potential sweep. These
findings represent a new example of qualitative different behavior
of nanoparticles in comparison with the corresponding bulk material.