摘要
High-pressure separations of binary and ternary mixtures of COb>2b>, CHb>4b>, and Hb>2b> are relevant to carbon dioxide capture as well as hydrogen and natural gas purification. Metal-organic frameworks represent a class of porous materials that could be used to accomplish these separations, and Mgb>2b>(dobdc) (dobdc4鈭?/sup> = 1,4-dioxido-2,5-benzenedicarboxylate), also sometimes referred to as Mg-MOF-74 or CPO-27-Mg, is an especially lightweight metal-organic framework with a high concentration of coordinatively-unsaturated metal sites decorating its interior surfaces. High pressure CHb>4b> adsorption isotherms presented here, together with COb>2b> and Hb>2b> adsorption behavior, are analyzed using the Ideal Adsorbed Solution Theory to model COb>2b>/CHb>4b>, CHb>4b>/Hb>2b>, and COb>2b>/CHb>4b>/Hb>2b> mixture separations using Mgb>2b>(dobdc). The selectivities, working capacities and breakthrough performances for these three mixtures are reported, and Mgb>2b>(dobdc) is shown to outperform zeolite 13X in each scenario.