Books and Chapters

Cover Gallery

Challenges in Water Electrolyzer
Challenges in Water Electrolyzer
Ru-Embedded Carbon Fabric
Ru-Embedded Carbon Fabric
Amine Chemistry of Porous CO2 Adsorbents
Amine Chemistry of Porous CO2 Adsorbents
Boronization of Nickel Foam for Sustainable Electrochemical Reduction of Nitrate to Ammonia
Boronization of Nickel Foam for Sustainable Electrochemical Reduction of Nitrate to Ammonia
How Reproducible are Surface Areas Calculated from the BET Equation?
How Reproducible are Surface Areas Calculated from the BET Equation?
Extensive Screening of Solvent-linked Porous Polymers through Friedel-Crafts Reaction for Gas Adsorption
Extensive Screening of Solvent-linked Porous Polymers through Friedel-Crafts Reaction for Gas Adsorption
Alkyl-linked porphyrin porous polymers for gas capture and precious metal adsorption
Alkyl-linked porphyrin porous polymers for gas capture and precious metal adsorption
Quantifying the nitrogen effect on CO2 capture using isoporous network polymers
Quantifying the nitrogen effect on CO2 capture using isoporous network polymers
Direct Access to Primary Amines and Particle Morphology Control in Nanoporous CO2 Sorbents
Direct Access to Primary Amines and Particle Morphology Control in Nanoporous CO2 Sorbents
Enhanced Sorption Cycle Stability and Kinetics of CO2 on Lithium Silicates Using the Lithium Ion Channeling Effect of TiO2 Nanotubes
Enhanced Sorption Cycle Stability and Kinetics of CO2 on Lithium Silicates Using the Lithium Ion Channeling Effect of TiO2 Nanotubes
  • Zwitterion π–conjugated nanoporous polymer based on guanidinium and β-ketoenol as a heterogeneous organo-catalyst for chemical fixation of CO2 into cyclic carbonates

    M. Garai, V. Rozyyev, Z. Ullah, A. Jamal, C. T. Yavuz
    APL Mater., 7, 111102
    2019
    Zwitterion π–conjugated nanoporous polymer based on guanidinium and β-ketoenol as a heterogeneous organo-catalyst for chemical fixation of CO2 into cyclic carbonates
    The chemical fixation of CO₂ with epoxides to cyclic carbonate is an attractive 100% atom economic reaction. It is a safe and green alternative to the route from diols and toxic phosgene. In this manuscript, we present a new zwitterionic π–conjugated nanoporous catalyst (Covalent Organic Polymer, COP-213) based on guanidinium and β-ketoenol functionality, that is synthesized from triaminoguanidinium halide (TGCl) and β-ketoenols via ampoule method at 120°C. The catalyst is characterized by NMR, FTIR-ATR, PXRD, TGA, and for surface area (BET) and CO₂ uptake. It shows quantitative conversion and selectivity in chemical fixation of CO₂ to epoxides under ambient conditions and without the need for co-catalysts, metals, solvent, or pressure. The catalyst can be recycled at least three times without loss of reactivity.
  • Fluorinated covalent organic polymers for high performance sulfur cathodes in lithium–sulfur batteries

    H. Shin§, D. Kim§, H. J. Kim§, J. Kim, K. Char, C. T. Yavuz, J. W. Choi. §: Equal contribution
    Chem. Mater., 31, 19, 7910-7921
    2019
    Fluorinated covalent organic polymers for high performance sulfur cathodes in lithium–sulfur batteries
    Lithium–sulfur (Li–S) batteries by far offer higher theoretical energy density than that of the commercial lithium-ion battery counterparts, but suffer predominantly from an irreversible shuttling process involving lithium polysulfides. Here, we report a fluorinated covalent organic polymer (F-COP) as a template for high performance sulfur cathodes in Li–S batteries. The fluorination allowed facile covalent attachment of sulfur to a porous polymer framework via nucleophilic aromatic substitution reaction (SNAr), leading to high sulfur content, e.g., over 70 wt %. The F-COP framework was microporous with 72% of pores within three well-defined pore sizes, viz. 0.58, 1.19, and 1.68 nm, which effectively suppressed polysulfide dissolution via steric and electrostatic hindrance. As a result of the structural features of the F-COP, the resulting sulfur electrode exhibited high electrochemical performance of 1287.7 mAh g–1 at 0.05C, 96.4% initial Columbic efficiency, 70.3% capacity retention after 1000 cycles at 0.5C, and robust operation for a sulfur loading of up to 4.1 mgsulfur cm–2. Our findings suggest the F-COP family with the adaptability of SNAr chemistry and well-defined microporous structures as useful frameworks for highly sustainable sulfur electrodes in Li–S batteries.
  • Processing nanoporous organic polymers in liquid amines

    J. Byun, D. Thirion, C. T. Yavuz
    Beilstein J. Nanotech., 10, 1844–1850
    2019
    Processing nanoporous organic polymers in liquid amines
    Rigid network structures of nanoporous organic polymers provide high porosity, which is beneficial for applications such as gas sorption, gas separation, heterogeneous (photo)catalysis, sensing, and (opto)electronics. However, the network structures are practically insoluble. Thus, the processing of nanoporous polymers into nanoparticles or films remains challenging. Herein, we report that nanoporous polymers made via a Knoevenagel-like condensation can be easily processed into nanoparticles (115.7 ± 40.8 nm) or a flawless film by using liquid amines as a solvent at elevated temperatures. FTIR spectra revealed that the carboxyl groups in the nanoporous polymers act as reactive sites for amines, forming new functionalities and spacing the polymeric chains to be dissolved in the liquid amines. The processed film was found to be CO₂-philic despite the low surface area, and further able to be transformed into a fine carbon film by thermal treatment.
  • High-capacity methane storage in flexible alkane-linked porous aromatic network polymers

    V. Rozyyev, D. Thirion, R. Ullah, J. Lee, M. Jung, H. Oh, M. Atilhan, C. T. Yavuz
    Nat. Energy, 4, 604-611
    2019
    High-capacity methane storage in flexible alkane-linked porous aromatic network polymers
    Adsorbed natural gas (ANG) technology is a viable alternative to conventional liquefied or compressed natural-gas storage. Many different porous materials have been considered for adsorptive, reversible methane storage, but fall short of the US Department of Energy targets (0.5 g g−1, 263 l l−1). Here, we prepare a flexible porous polymer, made from benzene and 1,2-dichloroethane in kilogram batches, that has a high methane working capacity of 0.625 g g−1 and 294 l l−1 when cycled between 5 and 100 bar pressure. We suggest that the flexibility provides rapid desorption and thermal management, while the hydrophobicity and the nature of the covalently bonded framework allow the material to tolerate harsh conditions. The polymer also shows an adsorbate memory effect, where a less adsorptive gas (N2) follows the isotherm profile of a high-capacity adsorbate (CO₂), which is attributed to the thermal expansion caused by the adsorption enthalpy. The high methane capacity and memory effect make flexible porous polymers promising candidates for ANG technology.
  • Sustainable synthesis of superhydrophobic perfluorinated nanoporous networks for small molecule separation

    S. Kim§, D. Thirion§, T. S. Nguyen, B. Kim, N. A. Dogan, C. T. Yavuz. §: Equal contribution
    Chem. Mater., 31, 14, 5206-5213
    2019
    Sustainable synthesis of superhydrophobic perfluorinated nanoporous networks for small molecule separation
    Nanoporous polymers offer great promise in chemical capture and separations because of their versatility, scalability, and robust nature. Here, we report a general methodology for one-pot, metal-free, and room-temperature synthesis of nanoporous polymers by highly stable carbon–carbon bond formation. Three new polymers, namely, COP-177, COP-178, and COP-179, are derived from widely available perfluoroarenes and found to be superhydrophobic, microporous, and highly stable against heat, acid, base, and organic solvents. Nitrile, amine, and ether functionalities were successfully installed by SNAr-type postfunctionalization and were shown to increase CO2 uptake twice and CO2/N2 selectivity 4-fold. Due to its inherent superhydrophobicity, COP-177 showed high organic solvent uptake both in liquid and vapor form. Furthermore, in a first of its kind, by combining microporosity and hydrophobicity, COP-177 separated two small molecules with the same boiling point in a continuous column setting.
  • Inversion of dispersion: Colloidal stability of calixarene modified metal-organic framework nanoparticles in non-polar media

    U. Jeong N. A. Dogan, M. Garai, T. S. Nguyen, J. F. Stoddart, C. T. Yavuz
    J. Am. Chem. Soc., 141, 31, 12182-12186
    2019
    Inversion of dispersion: Colloidal stability of calixarene modified metal-organic framework nanoparticles in non-polar media
    Making metal–organic frameworks (MOFs) that are stabilized in nonpolar media is not as straightforward as making their inorganic nanoparticle counterparts, since surfactants penetrate through the porous structures or dissolve the secondary building units (SBUs) through ligand-exchange linker modulator mechanisms. Herein, we report that calixarenes stabilize UIO-66 nanoparticles effectively by remaining outside the grains through size exclusion, without pores becoming blocked, all the while providing amphiphilicity that permits the formation of stable colloidal dispersions with much narrower size distributions. Using the UIO-66 dispersed solutions, we show that smooth films from an otherwise immiscible polystyrene can be made feasibly.

Contact us now

Looking forward to creating value with you

Learn More >>