  In this paper, we focus on three specific interactions of dark sector in the
existence of baryonic matter and radiation. First, we attempt to assume
baryonic matter and radiation can affect the conversion between dark energy and
dark matter like the way catalyst influences the conversion rate of two
materials in some reversible chemical reactions. Then we present phase space
analysis for every special interaction model. Finally, for every case, we
obtain a stable attractor solution that can alleviate the coincidence problem.
