Solvent-Free Synthesis of HKUST-1 with Abundant Defect Sites and Its Catalytic Performance in the Esterification Reaction of Oleic Acid.

HKUST-1 has received increasing attention because of its potential applications in many fields, such as heterogeneous catalysis, sensors, gas storage, and separation. Herein, we report that HKUST-1 can be facilely prepared by heating a ground mixture of copper nitrate trihydrate and 1,3,5-benzenetricarboxylic acid in an autoclave at 80 °C for 10 h. The data from nitrogen sorption show that the obtained material, named HKUST-1-free, possesses a high BET specific surface area of 1671 m/g and a pore volume of 0.

Cholesterol-Mediated Anchoring of Phospholipids onto Proteinosomes for Switching Membrane Permeability.

Modulated membrane functionalization is a necessary and overarching step for hollow microcompartments toward their application as nanoreactors or artificial cells. In this study, we show a way to generate phospholipid hybrid proteinosomes that could show superposed virtues of liposomes and proteinosomes. In comparison to pure proteinosomes, both the membrane fluidity and permeability are improved obviously after forming the phospholipid hybrid proteinosomes.

Amino-assisted AHMT anchored on graphene oxide as high performance adsorbent for efficient removal of Cr(VI) and Hg(II) from aqueous solutions under wide pH range.

The adsorbents with high adsorption capacity for simultaneously removing Cr(VI) and Hg(II) from aqueous solutions under broad working pH range are highly desirable but still extremely scarce. Here, a novel adsorbent with multidentate ligands was facilely fabricated by covalently bonding 4-amino-3-hydrazino-5-mercapto- 1,2,4-triazole on graphene oxide via the Schiff's base reaction. The maximum adsorption capacities of Cr(VI) and Hg(II) on the current adsorbent were 734.

Cross-linked sulfydryl-functionalized graphene oxide as ultra-high capacity adsorbent for high selectivity and ppb level removal of mercury from water under wide pH range.

It is highly desirable but remains extremely challenging to develop a facile strategy to prepare adsorbent for dealing with heavy metal pollution in water. Here, we report a facile approach for preparing sulfydryl-functionalized graphene oxide (S-GO) by cross-linking method with an unprecedented adsorption capacity and ultrahigh selectivity for efficient Hg(II) removal. The adsorbents exhibit a prominent performance in capturing Hg(II) from wastewater with a record-high adsorption capacity of 3490 mg/g and rapid kinetics to reduce Hg(II) contaminants below the discharge standard of drinking water (2 ppb) within 60 min under a wide pH range even in the coexistent of other interfering metal ions.

Highly efficient and ultrafast removal of Cr(VI)in aqueous solution to ppb level by poly(allylamine hydrochloride) covalently cross-linked amino-modified graphene oxide.

We herein report a facile strategy to prepare poly(allylamine hydrochloride) cross-linked amino-modified graphene oxide (PAH-ASGO) by Schiff-base reactions. The resulting PAH-ASGO exhibited a maximum adsorption capacity of 373.1 mg/g for Cr(VI), which was nearly 9 times higher than that of pure graphene oxide, exceeding that of most GO-based materials previously reported.

A green approach for enhancing the hydrophobicity of UiO-66(Zr) catalysts for biodiesel production at 298 K.

Recently, the incorporation of hydrophobicity on the surface of UiO-66(Zr) has received much attention due to the deactivation of hydrophilic active sites of UiO-66(Zr) upon water adsorption. In this work, we report UiO-66(Zr) catalysts with an assortment of surface hydrophobicities fabricated by the solvent-free method to elucidate the impact of the environment framing Lewis acid sites on their catalytic activity in the production of fatty acid methyl ester (biodiesel) the esterification of fatty acids at room temperature with high selectivity (100%) and good recyclability. A detailed structural analysis of the materials by N sorption, FT-IR, SEM, XRD, water contact angle measurement, dynamic liquid scattering (DLS), NMR and TGA revealed the fabrication of stearic acid-grafted UiO-66(Zr) catalysts (10SA/UiO-66) with fine particle size and a highly hydrophobic network.

Refinement of pore size at sub-angstrom precision in robust metal-organic frameworks for separation of xylenes.

The demand for xylenes is projected to increase over the coming decades. The separation of xylene isomers, particularly p- and m-xylenes, is vital for the production of numerous polymers and materials. However, current state-of-the-art separation is based upon fractional crystallisation at 220 K which is highly energy intensive.

Amino-functionalized graphene oxide-supported networked Pd-Ag nanowires as highly efficient catalyst for reducing Cr(VI) in industrial effluent by formic acid.

Cr(VI) pollution in wastewater has increasingly become a global environmental problem owing to its acute toxicity. Herein, we present the one-pot procedure for preparing the amino-functionalized (-NH) graphene oxide (GO-) supported networked Pd-Ag nanowires by co-reduction growth in polyol solution, which show the highly efficient catalytic performance with the excellent cycling stability for the catalytic Cr(VI) reduction by formic acid as an in-situ source of hydrogen at room temperature. The electron transfer from Ag and amino to Pd increases the electron density of Pd, which enhances the catalytic formic acid decomposition and subsequent the catalytic Cr(VI) reduction.

One-pot synthesis of magnetic graphene oxide composites as an efficient and recoverable adsorbent for Cd(II) and Pb(II) removal from aqueous solution.

It is extremely desirable but challenging to develop a facile synthesis method to directly prepare reusable and longtime stable magnetic graphene oxide (GO) adsorbent. Here, a new approach to prepare a magnetic GO for removing the heavy metal ions is reported by using n-Propyltrimethoxysilane (NPTS) as a cross-coupling agent to connect FeO/SiO and GO. The as-prepared magnetic GO can be separated quickly from their aqueous solution by the permanent magnet and also exhibited excellent adsorption performance for Cd(II) and Pb(II) with maximum adsorption capacities for Cd(II) and Pb(II) to 128.

Boosting Catalytic Performance of Metal-Organic Framework by Increasing the Defects via a Facile and Green Approach.

The control of defects in crystalline materials has long been of significance since the defects are correlated with the performances of the materials. Yet such control remains a challenge for metal-organic frameworks (MOFs), which are usually well-crystallized under hydro-/solvothermal conditions. In this contribution, we demonstrate for the first time how to increase the defects of MOF via a facile and green approach as exemplified in the context of solvent-free synthesis of UiO-66(Zr).

Enhancement of Oxidative Desulfurization Performance over UiO-66(Zr) by Titanium Ion Exchange.

Oxidative desulfurization is considered to be one of the most promising methods for producing ultra-low-sulfur fuels because it can effectively remove refractory sulfur-containing aromatic compounds under mild conditions. In this work, the oxidative desulfurization performance over UiO-66(Zr) is greatly enhanced by Ti ion exchange. This strategy is not only efficient for UiO-66(Zr) with crystal defects but also for UiO-66(Zr) with high crystallinity.

Inserting CO2 into Aryl C-H Bonds of Metal-Organic Frameworks: CO2 Utilization for Direct Heterogeneous C-H Activation.

Described for the first time is that carbon dioxide (CO2 ) can be successfully inserted into aryl C-H bonds of the backbone of a metal-organic framework (MOF) to generate free carboxylate groups, which serve as Brønsted acid sites for efficiently catalyzing the methanolysis of epoxides. The work delineates the very first example of utilizing CO2 for heterogeneous C-H activation and carboxylation reactions on MOFs, and opens a new avenue for CO2 chemical transformations under mild reaction conditions.

Metal-organic framework based upon the synergy of a Brønsted acid framework and Lewis acid centers as a highly efficient heterogeneous catalyst for fixed-bed reactions.

We report a strategy of combining a Brønsted acid metal-organic framework (MOF) with Lewis acid centers to afford a Lewis acid@Brønsted acid MOF with high catalytic activity, as exemplified in the context of MIL-101-Cr-SO3H·Al(III). Because of the synergy between the Brønsted acid framework and the Al(III) Lewis acid centers, MIL-101-Cr-SO3H·Al(III) demonstrates excellent catalytic performance in a series of fixed-bed reactions, outperforming two benchmark zeolite catalysts (H-Beta and HMOR). Our work therefore not only provides a new approach to achieve high catalytic activity in MOFs but also paves a way to develop MOFs as a new type of highly efficient heterogeneous catalysts for fixed-bed reactions.

Investigation of prototypal MOFs consisting of polyhedral cages with accessible Lewis-acid sites for quinoline synthesis.

A series of prototypal metal-organic frameworks (MOFs) consisting of polyhedral cages with accessible Lewis-acid sites, have been systematically investigated for Friedländer annulation reaction, a straightforward approach to synthesizing quinoline and its derivatives. Amongst them MMCF-2 demonstrates significantly enhanced catalytic activity compared with the benchmark MOFs, HKUST-1 and MOF-505, as a result of a high-density of accessible Cu(II) Lewis acid sites and large window size in the cuboctahedral cage-based nanoreactor of MMCF-2.

Microporous magnesium and manganese formates for acetylene storage and separation.

Acetylene sorption of microporous metal formates M(HCOO)2 (M = Mg and Mn) was investigated. Measurements of acetylene sorption at 196, 275, and 298 K showed a Type I isotherm with quick saturation at low pressures, and 50-75 cm3 g(-1) uptake at 1.0 atm.

Neopentane and solid acids: direct hydron exchange before cracking.

The hydrogen/deuterium exchange reaction of 2,2-dimethylpropane (neopentane) over D(2)O-exchanged zeolites (MOR, FAU, BEA, MFI) using a batch recirculation reactor was studied by means of gas chromatography coupled with mass spectrometer. In the temperature range 473-573 K, H/D exchange proceeds without side reaction such as cracking at short contact times. Indeed the C-H bond has appeared favorably involved in the activation of neopentane compared to the less accessible C-C bond.

Solvent-free preparation of nanosized sulfated zirconia with Brønsted acidic sites from a simple calcination.

Nanosized sulfated zirconia with Brønsted acidic sites has been prepared by a simple calcination in the absence of any solvent. XRD patterns reveal that the sulfated zirconia mainly consists of tetragonal crystalline zirconia with average size of about 7 nm, which is further confirmed by TEM images. N2 adsorption data show that the nanosized sulfated zirconia has high surface area (165-193 m2/g) and exhibits uniform pore distribution aggregated by zirconia nanoparticles.