University of California

Exxonmobil Research and Engineering Company

Exxonmobil Technology and Engineering Company

Jeffrey D Martell

Simon Christopher Weston

Jeffrey R Long

Phillip J Milner

Rebecca L Siegelman

Joseph M Falkowski

Eugene J Kim

Primary, secondary (1&#xb0;,2&#xb0;) alkylethylenediamine- and alkylpropylenediamine-appended variants of metal-organic framework are provided for COcapture applications. Increasing the size of the alkyl group on the secondary amine enhances the stability to diamine volatilization from the metal sites. Two-step adsorption/desorption profiles are overcome by minimzing steric interactions between adjacent ammonium carbamate chains. For instance, the isoreticularly expanded framework Mg(dotpdc) (dotpdc=4,4&#x2033;-dioxido-[1,1':4&#x2032;,1&#x2033;-terphenyl]-3,3&#x2033;-dicarboxylate), yields diamine-appended adsorbents displaying a single COadsorption step. Further, use of the isomeric framework Mg-IRMOF-74-II or Mg(pc-dobpdc) (pc-dobpdc=3,3-dioxidobiphenyl-4,4-dicarboxylate, pc=para-carboxylate) also leads to a single COadsorption step with bulky diamines. By relieving steric interactions between adjacent ammonium carbamate chains, these frameworks enable step-shaped COadsorption, decreased water co-adsorption, and increased stability to diamine loss. Variants of Mg(dotpdc) and Mg(pc-dobpdc) functionalized with large diamines such as N-(n-heptyl)ethylenediamine have utility as adsorbents for carbon capture applications.

Overcoming two carbon dioxide adsorption steps in diamine-appended metal organic frameworks

Polyamines with lengths carefully tailored to the framework dimensions are appended to metal-organic frameworks such as Mg(dobpdc) (dobpdc4-=4,4'-dioxidobiphenyl-3,3&#x2032;-dicarboxylate) with the desired loading of one polyamine per two metal sites. The polyamine-appended materials show step-shaped adsorption and desorption profiles due to a cooperative COadsorption/desorption mechanism. Several disclosed polyamine-appended materials exhibit strong ability to capture COfrom various compositions. Increased stability of amines in the framework has been achieved using high molecular weight polyamine molecules that coordinate multiple metal sites in the framework. The preparation of these adsorbents as well as their characterization are provided.

Polyamine-appended metal-organic frameworks for carbon dioxide separations

Primary, secondary (1&#xba;,2&#xba;) alkylethylenediamine- and alkylpropylenediamine-appended variants of metal-organic framework are provided for COcapture applications. Increasing the size of the alkyl group on the secondary amine enhances the stability to diamine volatilization from the metal sites. Two-step adsorption/desorption profiles are overcome by minimizing steric interactions between adjacent ammonium carbamate chains. For instance, the isoreticularly expanded framework Mg(dotpdc) (dotpdc=4,4&#x2033;-dioxido-[1,1':4&#x2032;,1&#x2033;-terphenyl]-3,3&#x2033;-dicarboxylate), yields diamine-appended adsorbents displaying a single COadsorption step. Further, use of the isomeric framework Mg-IRMOF-74-II or Mg(pc-dobpdc) (pc-dobpdc=3,3-dioxidobiphenyl-4,4-dicarboxylate, pc=para-carboxylate) also leads to a single COadsorption step with bulky diamines. By relieving steric interactions between adjacent ammonium carbamate chains, these frameworks enable step-shaped COadsorption, decreased water co-adsorption, and increased stability to diamine loss. Variants of Mg(dotpdc) and Mg(pc-dobpdc) functionalized with large diamines such as N-(n-heptyl)ethylenediamine have utility as adsorbents for carbon capture applications.

Overcoming two carbon dioxide adsorption steps in diamine-appended metal-organic frameworks

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Berkeley, CA, United States of America

Jeffrey D Martell