Linker exchange in zeolitic imidazolate frameworks
AssigneeExxonMobil Research and Engineering Company
InventorsZheng Ni, Mobae Afeworki, Simon Christopher Weston, John Zengel, David Lawrence Stern
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Abstract
A method is provided for replacing at least a portion of the organic linker content of a zeolitic imidazolate framework composition. The method comprises exchanging the organic linker with another organic linker. Also provided is a new material, designated as EMM-19, and a method of using EMM-19 to adsorb gases, such as carbon dioxide.
Claims32
A method for exchanging imidazolate linker in a zeolitic imidazolate framework composition, said method comprising the steps of:
- (a) providing a first zeolitic imidazolate framework composition having a tetrahedral framework comprising a general structure, M1-IMa-M2, wherein M1 and M2 comprise the same or different metal cations, and wherein IMa is an imidazolate or a substituted imidazolate linking moiety;
- (b) providing a liquid composition comprising IMb, wherein IMb is an imidazolate or a substituted imidazolate which is different from IMa;
- and (c) contacting the first zeolitic imidazolate framework composition with the liquid composition under conditions sufficient to exchange at least a portion of IMa with at least a portion of IMb and to produce a second zeolitic imidazolate framework composition, M1-IMc-M2, wherein IMc comprises IMb, and wherein the framework type of the second zeolitic imidazolate framework composition is different from the framework type obtained when a zeolitic imidazolate framework composition is prepared by crystallizing a liquid reaction mixture comprising a solution of M1, M2 and IMb.
A zeolitic imidazolate framework composition with an SOD framework type, wherein the zeolitic imidazolate framework structure is capable of sorbing, at a temperature of ˜28° C.:
- (i) at least 0.30 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜75 Torr;
- (ii) at least 0.35 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜100 Torr;
- and/or (iii) at least 0.50 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜200 Torr.
A zeolitic imidazolate framework composition having an empirical formula, Zn(5-azabenzimidazolate)2, wherein the zeolitic imidazolate framework structure is capable of sorbing, at a temperature of ˜28° C.:
- (i) at least 0.30 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜75 Torr;
- (ii) at least 0.35 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜100 Torr;
- and/or (iii) at least 0.50 mmol of CO2 per gram of zeolitic imidazolate framework composition at a CO2 partial pressure of ˜200 Torr.
A composition of matter having an empirical formula Zn(5-azabenzimidazolate)2 and exhibiting an SOD framework type.
Dependencies are inferred from the claim text.