Duo Wang

Bio: Duo Wang is an academic researcher. The author has contributed to research in topics: Catalysis & Lewis acids and bases. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.

Two Co(II)-Based MOFs Constructed from Resorcin[4]Arene Ligand: Syntheses, Structures, and Heterogeneous Catalyst for Conversion of CO2

Abstract: Two Co(II)-based metal–organic frameworks (MOFs) with open channels, [(CH3)2NH2]2[Co5L(H2O)8]·4H2O (1) and [Co6L(DMF)2(H2O)8]·2H2O (2), were synthesized using resorcin[4]arene ligand (H12L). Compounds 1 and 2 exhibit different 3D microporous framework structures: 1 possesses two kinds of open channels parallel to the a-axis (ca. 5.0 × 5.0 A) and the b-axis (ca. 4.0 × 6.0 A), and 2 is an open framework with a window size of 5.6 × 5.6 A. The activated crystal 1 involves many Lewis acid sites; thus, 1 shows prominent activity and recyclability for the reaction of carbon dioxide coupled with epoxides. Most strikingly, catalyst 1 can be reused for five successive cycles and provides outstanding catalytic activity.

ZIF-95 as a filler for enhanced gas separation performance of polysulfone membrane

Abstract: Metal–organic frameworks (MOFs) are found to be promising porous crystalline materials for application in gas separation. Considering that mixed matrix membranes usually increase the gas separation performance of a polymer by increasing selectivity, permeability, or both (i.e., perm-selectivity), the zeolitic imidazole framework-95 (ZIF-95) MOF was dispersed for the first time in polysulfone (PSF) polymer to form mixed matrix membranes (MMMs), namely, ZIF-95/PSF. The fabricated ZIF-95/PSF membranes were examined for the separation of various gases. The characterization of solvothermally synthesized ZIF-95 was carried out using different analyses such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), porosity measurements, etc. ZIF-95 was mixed with PSF at 8%, 16%, 24%, and 32% weight percent to form different loading MMMs. SEM analysis of membranes revealed good compatibility/adhesion between the MOF and polymer. The permeability of He, H2, O2, CO2, N2, and CH4 were measured for the pure and composite membranes. The ideal selectivity of different gas pairs were calculated and compared with reported mixed matrix membranes. The maximum increases in permeabilities were observed in 32% loaded membrane; nevertheless, these performance/permeability increases were at the expense of a slight decrease of selectivity. In the optimally loaded membrane (i.e., 24 wt% loaded membrane), the permeability of H2, O2, and CO2 increased by 80.2%, 78.0%, and 67.2%, respectively, as compared to the pure membrane. Moreover, the selectivity of H2/CH4, O2/N2, and H2/CO2 gas pairs also increased by 16%, 15%, and 8% in the 24% loaded membrane, respectively.

Two Novel Pyrene Tetra-Sulfonate Europium Coordination Polymers: Structure Formation Mechanism Analysis and Sequential Modulation Strategy

Abstract: For the purpose of broadening the understanding of the sulfonic acid coordination mechanism, a coordination system consisting of Eu(III) ion and 1,3,6,8-pyrene tetra-sulfonate (1,3,6,8-PTS) ligand was chosen as the typical research object. By step regulating the volume ratio of mixed solvents and the molar ratio of metal salts to ligands, two pyrene tetra-sulfonate europium coordination polymers, Eu6(μ6-O)(μ3-OH)8(NO3)6(1,3,6,8-H2PTS)(H2O)10 (1) and Eu(NO3)(1,3,6,8-PTS)0.5(H2O)3·0.5bipy (2), were obtained in sequence. Compound 1 shows a 1D chain-like structure interconnected with 1,3,6,8-PTS bridging ligands and rare [Eu6(μ6-O)(μ3-OH)8(NO3)6]2+ cluster nodes, while compound 2 shows a 2D layered structure. Further structural comparison with compound Eu(1,3,6,8-PTS)(H2O)7·4H2O·Hbipy (EuPTSbp-1) was discussed in detail and the structure formation mechanism was analyzed. On this basis, a sequential modulation strategy for pyrene tetra-sulfonate europium coordination polymers was proposed.