Wenge Qiu

A pcu-type metal–organic framework based on covalently quadruple cross-linked supramolecular building blocks (SBBs): structure and adsorption properties

A flexible ligand with two 1,3-benzenedicarboxylate units has been used to construct a microporous metal–organic framework with pcu topology based on supramolecular building blocks (SBBs). The obtained Cu(II) MOF exhibits a noticeable CO2 adsorption hysteresis and a comparable methane adsorption capacity at room temperature.

NOx selective catalytic reduction by ammonia over Cu-ETS-10 catalysts

Abstract Ion exchange method was used to fabricate Cu-ETS-10 titanosilicate catalysts, which possessed high activity, N 2 selectivity and SO 2 resistance for NO x selective catalytic reduction (SCR). N 2 sorption measurements indicated that the microporous catalysts had high surface areas of 288–380 m 2 /g. The Cu content and speciation were investigated by inductively coupled plasma atomic emission spectrometry, H 2 temperature-programmed reduction, and diffuse reflectance infrared Fourier transform spectroscopy. Various Cu species coexisted within the catalyst. Isolated Cu 2+ species were the active sites for NH 3 -SCR, the number of which initially increased and then decreased with increasing Cu content. The catalytic activity of Cu-ETS-10 depended on the isolated Cu 2+ species content.

A Copper-Based Metal-Organic Framework as an Efficient and Reusable Heterogeneous Catalyst for Ullmann and Goldberg Type C–N Coupling Reactions

A highly porous metal-organic framework (Cu-TDPAT), constructed from a paddle-wheel type dinuclear copper cluster and 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine (H6TDPAT), has been tested in Ullmann and Goldberg type C–N coupling reactions of a wide range of primary and secondary amines with halobenzenes, affording the corresponding N-arylation compounds in moderate to excellent yields. The Cu-TDPAT catalyst could be easily separated from the reaction mixtures by simple filtration, and could be reused at least five times without any significant degradation in catalytic activity.

Direct synthesis of N-sulfenylimines through oxidative coupling of amines with disulfides/thiols over copper based metal–organic frameworks

A highly porous metal–organic framework based on supramolecular building blocks with pcu-topology (pcu-MOF) has been tested for the oxidative coupling of amines and disulfides or thiols to afford the N-sulfenylimines directly in good yields without the formation of N-sulfinyl- and N-sulfonylimines. The pcu-MOF catalyst could be easily recovered from the reaction mixture by simple filtration, and could be reused at least five times without any substantial loss in the yield. The control experiments and mechanistic studies suggested that the oxidative coupling process involved the imine formation and the N–S coupling reaction.

Preparation of Ir@Pt Core–Shell Nanoparticles and Application in Three-Way Catalysts

The Ir@Pt core–shell spherical nanoparticles with Pt deposited on Ir cores were synthesized for the first time using successive reduction method based on epitaxial growth. The Ir@Pt/SiO2 core–shell structure catalysts were used in the three-way catalysts of controlling automobile exhaust emission, which exhibited high catalytic activity of NO reduction in three-way catalytic reaction.Graphical AbstractHAADF-STEM image (a) and definitive EDS line-scan spectrum (b) of Ir@Pt NPs with Ir/Pt molar ratio of 1/4FT-IR spectra of CO adsorption of Ir/SiO2 and Ir@Pt (1/1)/SiO2 catalysts

The Keggin Structure: An Important Factor in Governing NH3–SCR Activity Over the V2O5–MoO3/TiO2 Catalyst

Heteropolyacids and their salts have been effectively used in selective catalytic reduction because of the Keggin structure and extraordinarily strong acidity. Catalysts with and without the Keggin structure were synthesized to further investigate the effects of heteropolyoxometallate on low temperature NH3–SCR. XRD, BET, Raman, H2–TPR, NH3–TPD, FT-IR, and SO2–TPD techniques were used to characterize the physicochemical characteristics of the catalysts. Results indicate that catalysts with the Keggin structure had more surface Brönsted and Lewis acid sites, and these catalysts had significantly improved performances in the SCR reaction and in SO2 poisoning resistance.Graphical Abstract

Effects of SO 2 treatment of commercial catalysts on selective catalytic reduction of NO x by NH 3

Nitrogen oxide(NOx) emitted from stationary and mobile sources is a major air pollutant. Selective catalytic reduction(SCR) of NOx over a catalyst is a main technology for NOx elimination. Catalysts used for practical applications would be deactivated in flue containing SO2. In this work, three typical commercial catalysts were investigated before and after SO2 treatment. The catalysts were characterized by X-ray diffraction(XRD), X-ray fluorescene(XRF), temperature programme reduction(TPR), temperature programme desorption(TPD) and diffuse reflectance Fourier transform infrared(DRIFT) techniques. Results showed that SO2 treatment significantly influenced the performance of V2O5/TiO2 catalyst. The amount of V2O5 in the catalyst primarily affected the accumulation of sulfur species in the SO2 atmosphere. The performance of catalysts with small amounts of V2O5 could be improved under the same experimental conditions for acidity enhancement.

Poly[[bis­(dimethyl­formamide)[μ7-5,5′-(methyl­enedi­oxy)diisophthalato]dizinc] dimethyl­formamide monosolvate]

In the crystal structure of the title coordination polymer, {[Zn2(C17H8O10)(C3H7NO)2]·C3H7NO}n, the molecular building block (MBB), viz. {Zn2(CO2)4(C3H7NO)2}, comprises two zinc atoms, each bridged by three carboxylate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal–pyramidal, and square–pyramidal formed by the two coordinated dimethylformamide molecules and three carboxylate groups, and a distorted tetrahedral coordination defined by carboxylate groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.

catena-Poly[[bis­(pyridine-κN)zinc(II)]-μ-benzene-1,4-dicarboxyl­ato-κ2O1:O4]

In the title coordination polymer, [Zn(C8H4O4)(C5H5N)2]n, the ZnII atom, located on a twofold rotation axis, is tetracoordinated by two monodentate O atoms from two different carboxylate groups and two pyridyl N atoms, forming a distorted tetrahedral geometry. The ZnII atoms are bridged by terephthalate ligands, generating an infinite zigzag chain along [101].