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| 2. |
- Li, Jian, et al.
(author)
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A 3D extra-large-pore zeolite enabled by 1D-to-3D topotactic condensation of a chain silicate
- 2023
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 379:6629, s. 283-287
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Journal article (peer-reviewed)abstract
- Zeolites are microporous silicates with a large variety of applications as catalysts, adsorbents, and cation exchangers. Stable silica-based zeolites with increased porosity are in demand to allow adsorption and processing of large molecules but challenge our synthetic ability. We report a new, highly stable pure silica zeolite called ZEO-3, which has a multidimensional, interconnected system of extra-large pores open through windows made by 16 and 14 silicate tetrahedra, the least dense polymorph of silica known so far. This zeolite was formed by an unprecedented one-dimensional to three-dimensional (1D-to-3D) topotactic condensation of a chain silicate. With a specific surface area of more than 1000 square meters per gram, ZEO-3 showed a high performance for volatile organic compound abatement and recovery compared with other zeolites and metal-organic frameworks.
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| 3. |
- Li, Ping, et al.
(author)
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Structures, protonation, and electrochemical properties of diiron dithiolate complexes containing pyridyl-phosphine ligands
- 2009
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In: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; :11, s. 1919-1926
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Journal article (peer-reviewed)abstract
- Diiron complexes containing pyridyl-phosphine ligands, that is, (mu-pdt)[Fe-2(CO)(5)L] (pdt = S(CH2)(3)S, L = Ph2PCH2Py, 3a; Ph2PPy, 3b) and (mu-pdt)[Fe(CO)(2)(PMe3)][Fe(CO)(2)L] (L = Ph2PCH2Py, 4a; Ph2PPy, 4b) were prepared as model complexes of the [FeFe]-hydrogenase active site. Protonation of 3a and 3b by HOTf afforded the pyridyl-nitrogen protonated products [3aH(N)][OTf] and [3bH(N)][OTf], respectively. The molecular structures of 3a, 3b, 4a, 4b, as well as [3aH(N)][OTf] and [3bH(N)][OTf] were confirmed by X-ray diffraction studies, which show that the Ph2PCH2Py ligand occupies the basal position both in 3a and its protonated species [3aH(N)][OTf], while the Ph2PPy ligand prefers the apical position in 3b and [3bH(N)][OTf]. The double protonation process of complex 4b was monitored by in situ IR, H-1 and P-31 NMR spectroscopy at low temperature. The spectroscopic evidence indicates that the protonation of 4b occurs first at the Fe-Fe bond and then at the pyridyl-nitrogen atom. Cyclic voltammograms reveal that protonation of 3a and 3b results in a considerable decrease in the overpotential for electrocatalytic proton reduction in the presence of HOTf, while the efficiency is not influenced by protonation. The electrocatalytic efficiency of 4a for proton reduction in the presence of HOAc in CH3CN-H2O (50:1, v/v) is 5 times higher than that in pure CH3CN.
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| 4. |
- Liang, Jiawei, et al.
(author)
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Performance and microbial communities of a novel integrated industrial-scale pulp and paper wastewater treatment plant
- 2021
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 278
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Journal article (peer-reviewed)abstract
- Ltd Paper production generates pulp and paper wastewater (PPW), and it is difficult to remove the high-level pollutants in PPW efficiently. Herein, an efficient industrial-scale pulp and paper wastewater treatment plant (PP-WWTP) that integrated physicochemical and biological processes is investigated and reported. This PP-WWTP treated 2.3 Mt of wastewater with 17,388 ± 1436 mg/L chemical oxygen demand (COD) annually. The PP-WWTP can effectively remove over 99.81% of the COD. In detail, the physical, anaerobic, aerobic and chemical steps accounted for 41.6%, 40.0%, 11.9%, and 6.5% of COD removal, respectively. The microbial communities of the bioreactors removed the pollutants efficiently and contained diverse microbes. Further metagenomic analyses of the bioreactors identified more than 90,000 genes/gene fragments encoding for carbohydrate-active enzymes (CAZys), demonstrating high lignocellulose degradation ability of the bioreactors at molecular level. The xylanase activity assay showed some lignocellulase in the bioreactors were functional. Recycling the residual heat from the PPW along with energy recovered from biological treatment of the PPW, in the form of biogas (20,000 m³/d), could generate more than 1.5 M USD benefits/y. The results of this study demonstrated that the integrated physicochemical and biological process for PPWW treatment could effectively remove pollutants while generating revenue.
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| 5. |
- Song, Yubao, et al.
(author)
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Suppression of the vibration and sound radiation of a sandwich plate via periodic design
- 2019
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In: International Journal of Mechanical Sciences. - : Elsevier. - 0020-7403 .- 1879-2162. ; 150, s. 744-754
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Journal article (peer-reviewed)abstract
- This paper investigates the suppression of vibration and sound radiation of a sandwich plate through the use of periodic design. A periodic sandwich plate is constructed and its dispersion relation is calculated. The vibration and sound radiation properties of the periodic sandwich plate are studied. Via the comparison of the periodic and bare sandwich plate, the effects of the periodic design on the vibration and sound radiation are analysed. Further, to know the sound radiation properties better, sound radiation efficiency of the periodic and bare sandwich plates is compared. In addition, the effects of the boundary conditions on the properties of the periodic sandwich plate are analysed. The numerical results demonstrate that the vibration and sound radiation are greatly suppressed over the stop band of the periodic sandwich plate. The suppression can also be obtained in part of pass bands. It is also shown that the periodic design can be an effective method for the reduction of the sound radiation efficiency. The suppression for the vibration and sound is greater than that caused by only increasing the mass of the plate in the designing frequency range.
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| 6. |
- Wang, Ning, et al.
(author)
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A proton-hydride diiron complex with a base-containing diphosphine ligand relevant to the FeFe -hydrogenase active site
- 2008
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In: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :44, s. 5800-5802
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Journal article (peer-reviewed)abstract
- A diiron dithiolate complex holding a mu-hydride on the iron atoms and a proton on the basic site of a chelating diphosphine ligand was prepared and crystallographically characterized as a structural model of the [FeFe]-hydrogenase active site, and its molecular structure shows the H-mu(-)center dot center dot center dot H-N(+) distance is 3.934 angstrom.
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| 7. |
- Wang, Ning, et al.
(author)
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Preparation, Facile Deprotonation, and Rapid H/D Exchange of the mu-Hydride Diiron Model Complexes of the FeFe -Hydrogenase Containing a Pendant Amine in a Chelating Diphosphine Ligand
- 2009
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 48:24, s. 11551-11558
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Journal article (peer-reviewed)abstract
- The CO-displacement of [(μ-pdt)Fe2(CO)6] with (Ph2PCH2)2N(n-Pr) in refluxing toluene gave an unsymmetrical chelating complex [(μ-pdt){Fe(CO)3}{Fe(CO)(κ2-Ph2PCH2N(n-Pr)CH2PPh2}] (1) as a major product, together with a small amount of the symmetrical intramolecular bridging complex [(μ-pdt){μ-Ph2PCH2N(n-Pr)CH2PPh2}{Fe(CO)2}2] (2) and the intermolecular bridging complex [{μ,κ1,κ1-Ph2PCH2N(n-Pr)CH2PPh2}{(μ-pdt)Fe2(CO)5}2] (3). In contrast, the reaction of [(μ-pdt)Fe2(CO)6] with (Ph2PCH2)2NR (R = n-Pr, Ph) afforded the intermolecular bridging isomers 3 and 4 in the presence of a CO-removing reagent Me3NO·2H2O in CH3CN at room temperature. The molecular structures of 1, 3, and 4, as well as the doubly protonated complex [1(HNHμ)](OTf)2] were determined by X-ray analyses. The protonation processes of 1 with HBF4·Et2O and HOTf were studied in different solvents. The presence of the Hμ···HN interaction in [1(HNHμ)]2+ was studied by relaxation time T1 and spin saturation transfer measurements. The μ-hydride of [1(Hμ)]+ and [1(HNHμ)]2+ undergo facile deprotonation with aniline and rapid H/D exchange with deuterons in solution. In contrast, neither deprotonation nor H/D exchange was detected for [(μ-H)(μ-pdt){Fe(CO)3}{Fe(CO)(κ2-dppp)}]+ ([5(Hμ)]+, dppp = Ph2PCH2CH2CH2PPh2) without internal base.
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| 8. |
- Xu, Yan, et al.
(author)
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Germanate with Three-Dimensional 12 x 12 x 11-Ring Channels Solved by X-ray Powder Diffraction with Charge-Flipping Algorithm
- 2013
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 52:18, s. 10238-10244
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Journal article (peer-reviewed)abstract
- A new open-framework germanate, denoted as GeO-JU90, was prepared by the hydrothermal synthesis method using 1,5-bis(methylpyrrolidinium)pentane dihydroxide as the organic structure-directing agent (SDA). The structure of GeO-JU90 was determined from synchrotron X-ray powder diffraction (XRPD) data using the charge-flipping algorithm. It revealed a complicated framework structure containing 11 Ge atoms in the asymmetric unit. The framework is built of 7-connected Ge-7 clusters and additional tetrahedral GeO3(OH) units forming a new three-dimensional interrupted framework with interesting 12 X 12 X 11-ring intersecting channels. The Ge K-edge extended X-ray absorption fine structure (EXAFS) analysis was performed to provide the local structural information around Ge atoms, giving rise to a first-shell contribution from about 4.2(2) O atoms at the average distance of 1.750(8) angstrom. The guest species subsequently determined by the simulated annealing method from XRPD data combining with other characterization techniques, e.g., C-13 NMR spectroscopy, infrared spectroscopy (FTIR), compositional analyses, and thermogravimetric analysis (TGA). Crystallographic data vertical bar(C15N2H32)(NH4)vertical bar[Ge11O21.5(OH)(4)], orthorhombic Ama2 (No. 40), a = 37.82959 angstrom, b = 15.24373 angstrom, c = 12.83659 angstrom, and Z = 8.
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| 9. |
- Zhang, Chuanqi, et al.
(author)
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An Extra-Large-Pore Zeolite with 24 x 8 x 8-Ring Channels Using a Structure-Directing Agent Derived from Traditional Chinese Medicine
- 2018
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In: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 57:22, s. 6486-6490
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Journal article (peer-reviewed)abstract
- Extra-large-pore zeolites have attracted much interest because of their important applications for processing larger molecules. Although great progress has been made in academic science and industry, it is challenging to synthesize these materials. A new extra-large-pore zeolite SYSU-3 (Sun Yat-sen University no?) has been synthesized by using a novel sophoridine derivative as an organic structure-directing agent (OSDA). The framework structure was solved and refined using continuous rotation electron diffraction (cRED) data from nanosized crystals. SYSU-3 exhibits a new zeolite framework topology, which has the first 24 x 8 x 8-ring extra-large pore system and a framework density (FD) as low as 11.4 T/1000 angstrom(3). The unique skeleton of the OSDA plays an essential role in the formation of the distinctive zeolite structure. This work provides a new perspective for developing new zeolilic materials by using alkaloids as cost-effective OSDAs.
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