COOPERATIVE CHEMICAL ADSORPTION OF ACID GASES IN FUNCTIONALIZED METAL-ORGANIC FRAMEWORKS

摘要

A system and method for acid gas separations using porous frameworks of metal atoms coordinatively bound to polytopic linkers that are functionalized with basic nitrogen ligands that expose nitrogen atoms to the pore volumes forming adsorption sites. Adjacent basic nitrogen ligands on the metal-organic framework can form an ammonium from one ligand and a carbamate from the other. The formation of one ammonium carbamate pair influences the formation of ammonium carbamate on adjacent adsorption sites. Adsorption of acid gas at the adsorption sites form covalently linked aggregates of more than one ammonium carbamate ion pair. The acid gas adsorption isotherm can be tuned to match the step position with the partial pressure of acid gas in the gas mixture stream through manipulation of the metal-ligand bond strength by selection of the ligand, metal and polytopic linker materials.

主权项

1. A method for acid gas separations, the method comprising:
(a) determining concentration of an acid gas from a stream of a mixture of gases; (b) preparing a porous metal organic framework of metal atoms bound to polytopic organic linkers; (c) selecting basic nitrogen ligands capable of binding with unsaturated metal ions of the organic framework with a binding strength; (d) binding said basic nitrogen ligands to coordinatively unsaturated metal ions that expose nitrogen atoms to pore volumes of the framework; and (e) contacting the framework with a stream of a mixture of gases; (f) wherein acid gas is adsorbed to said basic nitrogen ligands; and (g) wherein a step position of a produced isotherm is matched to the concentration of an acid gas from said stream of a mixture of gases.