Hydrotalcites (HTs) belong to a family of layered, double hydroxide solids that have been proven to be stable adsorbents under harsh conditions. The stoichiometry of these solids is where the divalent ion is typically Mg2+, the trivalent ion is typically Al3+, and the anion A is Cl−, NO3−, or CO32−. Although important members of this family containing Ga3+ substituted for some fraction of the Al3+ have been synthesized, there are no existing reports of CO2capture by these substituted hydrotalcites (SHTs). Here we report stable and reversible CO2adsorbents with very high capture capacity that feature Ga substituted, potassium carbonate promoted HTs: