  A new mechanism for reactivity of multiply twinned gold nanoparticles
resulting from their inherently strained structure provides a further
explanation of the surprising catalytic activity of small gold nanoparticles.
Atomic defect structural studies of surface strains and quantitative analysis
of atomic column displacements in the decahedral structure observed by
aberration corrected transmission electron microscopy reveal an average
expansion of surface nearest neighbor distances of 5.6 percent, with many
strained by more than 10 percent. Density functional theory calculations of the
resulting modified gold d-band states predict significantly enhanced activity
for carbon monoxide oxidation. The new insights have important implications for
the applications of nanoparticles in chemical process technology, including for
heterogeneous catalysis.
