New iron selenide superconductors by intercalating smaller-sized alkali metals (Li, Na) and alkaline earths using high-temperature routes have been pursued ever since the discovery of superconductivity at about 30 K in (K, Rb, or Cs)Fe2Se2, but all have failed so far. Here we demonstrate that a series of superconductors with enhanced Tc = 30~46 K can be obtained by intercalating metals, Li, Na, Ba, Sr, Ca, Yb, and Eu in between FeSe layers by the liquid ammonia method at room temperature. The findings provide a new starting point for studying the properties of these superconductors and an effective synthetic route for the exploration of new superconductors as well.