High and Selective CO₂ Uptake in a Cobalt Adeninate Metal−Organic Framework Exhibiting Pyrimidine- and Amino-Decorated Pores

Abstract

The synthesis and structure of Co(2)(ad)(2)(CO(2)CH(3))(2) x 2 DMF x 0.5 H(2)O (bio-MOF-11) is described. Pyrimidine and amino groups of adeninate (ad) decorate the pores of the framework. The porosity of this material was studied, and its CO(2) and H(2) adsorption properties were evaluated. bio-MOF-11 exhibits a high heat of adsorption for CO(2) (approximately 45 kJ/mol), a high CO(2) capacity (approximately 6 mmol/g, 273 K), and exceptional selectivity for CO(2) over N(2) at 273 K (81:1) and 298 K (75:1).

Porous covalent electron-rich organonitridic frameworks as highly selective sorbents for methane and carbon dioxide

“…S13 and S14). The value is much higher compared with the next-higher value reported so far (81:1 at 273 K) 4 . Bae et al 38 reported a CO 2 /N 2 selectivity of 95 at 298 K for a carborane-based metal-organic framework.…”

“…To further understand the pore surface characteristics of the materials and the adsorption process, we have calculated the isosteric heats of adsorption (∆H) for CO 2 and CH 4 . ∆H was calculated using the Clausius-Clapeyron equation from the sorption data collected at 273, 298, and 323 K (refs 4,37).…”

“…In addition to the high CO 2 uptake and the reversibility, a high selectivity for CO 2 over N 2 is one of the necessary properties for a material to be used as a CO 2 adsorbent. The selectivity for the PECONF monoliths was estimated using the ratios of the Henry law constants 4 . These constants can be calculated from the initial slopes of the isotherms.…”

“…PECONF-4 has the highest CO 2 :CH 4 selectivity of 12 at 273 K among all the materials. However, the CH 4 : N 2 selectivity of 16 is maximum for PECONF-1 at 273 K. Sorbents with high selectivity for CH 4 over N 2 are of high practical interest, because methane is often highly diluted by N 2 in natural gas wells. Currently, N 2 /CH 4 separations are still being done cryogenically because of the absence of solid sorbents with high methane sorption capacities and suitable selectivities.…”

Analysis of High and Selective Uptake of CO2 in an Oxamide‐Containing {Cu2(OOCR)4}‐Based Metal–Organic Framework

“…[3c,6-10] Nitrogen-containing groups or open metal sites accessible within the pores can improve CO 2 affinity via dipolequadrupole interactions with the CO 2 molecules. [11][12][13][14] We recently described the material NOTT-122 incorporating triazole groups which displays a high adsorption capacity for CO 2 and used a computational approach to investigate the specific interactions between CO 2 and the framework linker heteroatoms. [15] Similarly, Zaworotko et al have reported MOFs [16] containing amide functional groups in the linkers, whereby linking of three isophthalates generated polyhedral structures that exhibit a strong binding affinity to CO 2 .…”