A hyper-crosslinked β-cyclodextrin porous polymer (BnCD-HCPP) was designed and synthesized facilely by β-cyclodextrin benzylation and subsequent crosslinking a Friedel-Crafts alkylation route. The BnCD-HCPP shows an extremely high BET surface area, large pore volume, and high thermal stability, making it a highly efficient adsorbent for removal of aromatic pollutants from water. The adsorption efficiency in terms of distribution coefficient, defined as the ratio of adsorption capacity to equilibrium adsorbate concentration, ranged from 10 to 10 mL g within a concentration of 0-100 ppm, one order of magnitude higher than that of other β-cyclodextrin-based adsorbents reported previously.
View Article and Find Full Text PDFAn innovative strategy for post-synthesis nitrogen-doping of mesoporous carbons (MCs) with high yields (>90%) at low temperatures (230-380 °C) by using a strong base, sodium amide (NaNH2), was developed. The as-prepared N-doped MCs exhibit a significantly enhanced CO2 adsorption performance in terms of capacity and selectivity when compared to their parent MCs.
View Article and Find Full Text PDFPolymeric amines such as poly(ethylenimine) (PEI) supported on mesoporous oxides are promising candidate adsorbents for CO2 capture processes. An important aspect to the design and optimization of these materials is a fundamental understanding of how the properties of the oxide support such as pore structure, particle morphology, and surface properties affect the efficiency of the guest polymer in its interactions with CO2. Previously, the efficiency of impregnated PEI to adsorb CO2 was shown to increase upon the addition of Zr as a surface modifier in SBA-15.
View Article and Find Full Text PDFIn this communication, we report a facile approach to constructing catalytic active hierarchical interfaces in one-dimensional (1D) nanostructure, exemplified by the synthesis of TiO2-supported PtFe-FeO(x) nanowires (NWs). The hierarchical interface, constituting atomic level interactions between PtFe and FeO(x) within each NW and the interactions between NWs and support (TiO2), enables CO oxidation with 100% conversion at room temperature. We identify the role of the two interfaces by probing the CO oxidation reaction with isotopic labeling experiments.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
April 2015
A soft chemistry synthetic strategy based on a Friedel-Crafts alkylation reaction is developed for the textural engineering of phenolic resin (PR) with a robust mesoporous framework to avoid serious framework shrinkage and maximize retention of organic functional moieties. By taking advantage of the structural benefits of molecular bridges, the resultant sample maintains a bimodal micro-mesoporous architecture with well-preserved organic functional groups, which is effective for carbon capture. Moreover, this soft chemistry synthetic protocol can be further extended to nanotexture other arene-based polymers with robust frameworks.
View Article and Find Full Text PDFA porous liquid containing empty cavities has been successfully fabricated by surface engineering of hollow structures with suitable corona and canopy species. By taking advantage of the liquid-like polymeric matrices as a separation medium and the empty cavities as gas transport pathway, this unique porous liquid can function as a promising candidate for gas separation. Moreover, such a facile synthetic strategy can be further extended to the fabrication of other types of nanostructure-based porous liquid, opening up new opportunities for preparation of porous liquids with attractive properties for specific tasks.
View Article and Find Full Text PDFHigh-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energy and environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity.
View Article and Find Full Text PDFEfficient transformation of biomass-derived feedstocks to chemicals and fuels remains a daunting challenge in utilizing biomass as alternatives to fossil resources. A three-phase catalytic system, consisting of an aqueous phase, a hydrophobic ionic-liquid phase, and a solid-acid catalyst phase of nanostructured vanadium phosphate and mesostructured cellular foam (VPO-MCF), is developed for efficient conversion of biomass-derived fructose to 5-hydroxymethylfurfural (HMF). HMF is a promising, versatile building block for production of value-added chemicals and transportation fuels.
View Article and Find Full Text PDFWe report a carbon-based, three-dimensional nanofluidic transport membrane that enables gated, or on/off, control of the transport of organic molecular species and metal ions using an applied electrical potential. In the absence of an applied potential, both cationic and anionic molecules freely diffuse across the membrane via a concentration gradient. However, when an electrochemical potential is applied, the transport of ions through the membrane is inhibited.
View Article and Find Full Text PDFNanosized BaSO4-based mesoporous hybrid materials have been developed and identified as new efficient inorganic salt-based support systems for ultrastable gold nanoparticles in low-temperature CO oxidation.
View Article and Find Full Text PDFA general strategy for the synthesis of porous, fluorescent, triazine-framework-based membranes with intrinsic porosity through an aromatic nitrile trimerization reaction is presented. The essence of this strategy lies in the use of a superacid to catalyze the cross-linking reaction efficiently at a low temperature, allowing porous polymer membrane architectures to be facilely derived. With functionalized triazine units, the membrane exhibits an increased selectivity for membrane separation of CO(2) over N(2).
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