Provided herein are adsorbents and methods of using the adsorbents to at least partially remove one or more adsorbates. In an aspect, an adsorbate within a phase is at least partially removed by providing an adsorbent material and contacting the adsorbent material with the phase having an adsorbate, to at least partially remove the adsorbate. Various adsorbents are disclosed having the chemical formula RE1-x-y-zBxB′yB″zOw, where RE is RE is a rare earth metal, B is a trivalent metal ion, B′ is a transition metal ion or an alkaline earth element, B″ is a transition metal ion, 0≦x≦0.25, 0≦y≦0.95, 0≦z≦0.75, w is a number which results in charge balance, and x+y+z