The binary phase behavior of mixtures of CO 2 and highly CO 2-philic solids has been determined at 298 K. The solids include sugar acetates (β- d-galactose pentaacetate, β- d-ribofuranose tetraacetate, α- d(+)-glucose pentaacetate, d-(+)-sucrose octaacetate), tert-butylated aromatics (2,4-di- tert-butylphenol, 2,6-di- tert-butyl-4-methylphenol, 3,5-di- tert-butylphenol, 1,2,4-triacetoxybenzene), and a highly oxygenated cyclic compound (1,3,5-trioxane). The results are presented in the form of phase behavior (Px) diagrams at 298 K that exhibit either one (vapor–liquid–solid, VLS) or two (vapor–liquid–liquid, VL 1L 2 and vapor–liquid–solid, VL 2S) three-phase equilibrium lines. Ternary phase behavior at 298 K has also been determined and presented in the form of a pseudo-binary Px diagram for mixtures of an equimolar gas blend of CO 2 and H 2 and each of these CO 2-philic solids and several other previously identified highly CO 2-philic compounds. Only four compounds, sucrose octaacetate, 1,3,5-tri- tert-butylbenzene, 2,4-di- tert-butylbenzene, and 1,3,5-trioxane, melted at 298 K in the presence of the CO 2/H 2 mixture at three-phase vapor–liquid–solid pressures ranging between 6 MPa and 10 MPa. These four compounds are candidates for the selective absorption of CO 2 from a CO 2/H 2 mixture using solid compounds that can melt and selectively absorb CO 2.