  We use 2.5-D electromagnetic particle-in-cell simulation code to investigate
the acceleration of electrons in solar coronal holes through the interaction of
Alfv\'en waves with an interplume region. The interplume is modeled by a cavity
density gradients that are perpendicular to the background magnetic field. The
aim is to contribute to explain the observation of suprathermal electrons under
relatively quiet sun. Simulations show that Alfv\'en waves in interaction with
the interplume region gives rise to a strong local electric field that
accelerates electrons in the direction parallel to the background magnetic
field. Suprathermal electron beams and small-scale coherent structures are
observed within interplume of strong density gradients. These features result
from non linear evolution of the electron beam plasma instability.
