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In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage.

Hyo Park J, Choi KM, Jeon HJ, Jung Choi Y, Kang JK - Sci Rep (2015)

Bottom Line: Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature.The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage.This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science &Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.

ABSTRACT
Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

No MeSH data available.


Related in: MedlinePlus

The storage capacities for CO2 and CH4 adsorption and their corresponding cyclic performance.a, The CO2 storage capacities of pmg-MOF-5, MOF-5 and IRMOF-5 samples at room and low (inset) temperatures. b, The cyclic performance for CO2 adsorption cycles in the pmg-MOF-5. c, The CH4 storage capacities of pmg-MOF-5 and MOF-5 at room temperature. d, The cyclic performance of CH4 adsorption cycles in the pmg-MOF-5.
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f5: The storage capacities for CO2 and CH4 adsorption and their corresponding cyclic performance.a, The CO2 storage capacities of pmg-MOF-5, MOF-5 and IRMOF-5 samples at room and low (inset) temperatures. b, The cyclic performance for CO2 adsorption cycles in the pmg-MOF-5. c, The CH4 storage capacities of pmg-MOF-5 and MOF-5 at room temperature. d, The cyclic performance of CH4 adsorption cycles in the pmg-MOF-5.

Mentions: We have also explored the capacities of the pmg-MOF-5 for gas storage at room temperature (298 K) using the gravimetric method with the magnetic suspension balance (MSB, Rubotherm), as seen in Fig. 5. It was determined that the capacity of CO2 in the pmg-MOF-5 (1136 mg/g) at room temperature was very high compared to the 820 mg/g for the IRMOF-3 (Fig. 5a). This enhanced capacity of about 39% in the pmg-MOF-5 compared to the nitrogen-functionalized MOF-5 (so called as IRMOF-3)2324 for CO2 uptake at room temperature is very exceptional. It is notable that the IRMOF-3 gives this poor gravimetric CO2 sorption uptake capacity at room temperature while it shows the excellent adsorption capacity for CO2 molecules at a low temperature (Fig. 5a). Moreover, the sorption behavior of the pmg-MOF-5 at room temperature is found to be similar to that at a low temperature. Also, it shows the similar behavior to that for the pristine MOF-5 in a low-pressure region (<1 MPa) and gives enhancement by using meso/macropores in a high-pressure region (>1 MPa) (Fig. 5a and inset). In addition, we have determined CO2 cycling adsorption behaviors and its kinetics at room temperature and these support that the pmg-MOF-5 shows the robust capacity retention with no hysteresis for reversible CO2 sorption cycles (Fig. 5b).


In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage.

Hyo Park J, Choi KM, Jeon HJ, Jung Choi Y, Kang JK - Sci Rep (2015)

The storage capacities for CO2 and CH4 adsorption and their corresponding cyclic performance.a, The CO2 storage capacities of pmg-MOF-5, MOF-5 and IRMOF-5 samples at room and low (inset) temperatures. b, The cyclic performance for CO2 adsorption cycles in the pmg-MOF-5. c, The CH4 storage capacities of pmg-MOF-5 and MOF-5 at room temperature. d, The cyclic performance of CH4 adsorption cycles in the pmg-MOF-5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496785&req=5

f5: The storage capacities for CO2 and CH4 adsorption and their corresponding cyclic performance.a, The CO2 storage capacities of pmg-MOF-5, MOF-5 and IRMOF-5 samples at room and low (inset) temperatures. b, The cyclic performance for CO2 adsorption cycles in the pmg-MOF-5. c, The CH4 storage capacities of pmg-MOF-5 and MOF-5 at room temperature. d, The cyclic performance of CH4 adsorption cycles in the pmg-MOF-5.
Mentions: We have also explored the capacities of the pmg-MOF-5 for gas storage at room temperature (298 K) using the gravimetric method with the magnetic suspension balance (MSB, Rubotherm), as seen in Fig. 5. It was determined that the capacity of CO2 in the pmg-MOF-5 (1136 mg/g) at room temperature was very high compared to the 820 mg/g for the IRMOF-3 (Fig. 5a). This enhanced capacity of about 39% in the pmg-MOF-5 compared to the nitrogen-functionalized MOF-5 (so called as IRMOF-3)2324 for CO2 uptake at room temperature is very exceptional. It is notable that the IRMOF-3 gives this poor gravimetric CO2 sorption uptake capacity at room temperature while it shows the excellent adsorption capacity for CO2 molecules at a low temperature (Fig. 5a). Moreover, the sorption behavior of the pmg-MOF-5 at room temperature is found to be similar to that at a low temperature. Also, it shows the similar behavior to that for the pristine MOF-5 in a low-pressure region (<1 MPa) and gives enhancement by using meso/macropores in a high-pressure region (>1 MPa) (Fig. 5a and inset). In addition, we have determined CO2 cycling adsorption behaviors and its kinetics at room temperature and these support that the pmg-MOF-5 shows the robust capacity retention with no hysteresis for reversible CO2 sorption cycles (Fig. 5b).

Bottom Line: Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature.The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage.This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science &Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.

ABSTRACT
Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

No MeSH data available.


Related in: MedlinePlus