Article

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

Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA.
Journal of the American Chemical Society (Impact Factor: 11.44). 12/2009; 132(1):38-9. DOI: 10.1021/ja909169x
Source: PubMed

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).

0 Followers
 · 
278 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The high performance of polyethyleneimine (PEI)-based solid adsorbent for CO2 capture has been well recognized in thermogravimetric analysis (TGA) and small-scale fixed bed reactors through the measurements of their equilibrium capacities but has not been really demonstrated on larger scales towards practical utilization. In the present study, a laboratory-scale bubbling fluidized bed reactor loaded with a few kg adsorbent is used to evaluate the adsorption performance of PEI–silica adsorbent under different working conditions including with/without the presence of moisture, different gas–solid contact times, initial bed temperatures, and CO2 partial pressures. The adsorption capacities have shown a clear degradation tendency under dry condition. However, they can be stabilized at a high level of 10.6–11.1% w/w over 60 cycles if moisture (ca. 8.8 vol%) is present in the gas flow during adsorption and desorption. Breakthrough capacities can be stabilized at the level of 7.6–8.2% w/w with the gas–solid contact time of 13 s. The adsorption capacities for the simulated flue gases containing 5% CO2 are only slightly lower than those for the simulated flue gases containing 15% CO2, indicating that the PEI–silica adsorbent is suitable for CO2 capture from flue gases of both coal-fired and natural gas-fired combined cycle power plants. The exothermal heat of adsorption is estimated by the energy balance in the fluidized bed reactor and found to be close (within 10%) to the measured value by TG-DSC. The regeneration heat for the as-prepared PEI–silica adsorbent is found to be 2360 kJ/kgCO2 assuming 75% recovery of sensible heat which is well below the values of 3900–4500 kJ/kgCO2 for a typical MEA scrubbing process with 90% recovery of sensible heat.
    Chemical Engineering Journal 09/2014; 251:293–303. DOI:10.1016/j.cej.2014.04.063 · 4.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A nanosize Zr-metal organic framework (Zr-MOF, UiO-66) with a uniformed particle size around 100 nm was solvothermally synthesized and activated by solvent exchange method, vacuum drying and heating. The activation process with an exchangeable guest solvent produced the Zr-MOF with a high surface area by removal almost all guest and free terephthalic acid molecules from the pores enhancing its capacity for adsorption. The nanosize Zr-MOF also showed strong thermal stability up to 753 K. The Zr-MOF was tested for hydrogen and carbon dioxide adsorption at varying pressures and temperatures and it exhibited adsorption capacity of 1.6 wt% (H2) at 1 atm, 77 K and 79 cc (CO2) g−1 at 1 atm, 273 K, respectively. The heat of H2 adsorption was estimated to be 6–12 kJ mol−1 while the heat of CO2 adsorption was determined to be around 28 kJ mol−1.
    Chemical Engineering Journal 04/2012; 187:415–420. DOI:10.1016/j.cej.2012.01.104 · 4.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Six borazine-linked polymers (BLPs) have been synthesized through the thermolysis reaction of p-phenylenediamine, 1,3,5-tris-(4-aminophenyl)benzene, benzidine, or tetra-(4-aminophenyl)methane with boron tribromide or boron trichloride. Each product exists as an amorphous polymer whose chemical connectivity was confirmed by FT-IR and elemental analysis while thermogravimetric analysis revealed moderate thermal stabilities up to about 200 °C under nitrogen atmosphere. All BLPs possess high surface areas with chlorinated BLPs exhibiting higher values than brominated BLPs (1,174–1,569 vs. 503–849 m2/g, respectively). Gas storage capabilities were investigated as well. BLPs possess good hydrogen uptakes (0.68–1.75 wt% at 77 K) and zero-coverage isosteric heat of adsorption, Q st, (7.06–7.65 kJ/mol) as calculated by the virial method. The uptakes and heat of adsorption for carbon dioxide (51–141 mg/g at 273 K with Q st: 22.2–31.7 kJ/mol) are also attractive. BLPs do not, however, appear to exhibit significant methane storage capacities (1.9–15.2 mg/g at 273 K with Q st: 17.1–21.7 kJ/mol). Accordingly, CO2/CH4 selectivity studies were performed using the ideal adsorbed solution theory and further supported by initial slope calculations. The results indicate that BLP-1(Br) and BLP-2(Br) exhibit very high CO2/CH4 selectivities 23 and 26, respectively, which make them attractive for small gas separation applications.
    Journal of Nanoparticle Research 01/2013; 15(1). DOI:10.1007/s11051-012-1368-5 · 2.28 Impact Factor