“…Alkali and alkaline earth metals form bulk carbonates, and the adsorption of CO 2 on oxides of these metals is characterized by large H ∆ on the order of 160 kJ/mol at low surface coverage [Horiuchi, 1998a]. At similar coverage, rare earth oxides have H ∆ of about 100-140 kJ/mol [Horiuchi, 1998a]; perovskites have lower H ∆ on the order of 50 kJ/mol [Kusakabe, 1994], [Martin, 1981], [Liu, 2005]. Notably, the interaction of CO 2 with basic sites on metal oxides, including perovskites, rare earth oxides and semiconducting oxides, is important in metal oxide-catalyzed reactions such as oxidative coupling of methane, CO 2 reforming of methane, and water gas shift [Tsuji, 2003], [Liu, 2005], [Istadi, 2004].…”