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In this paper, sulfur-doped carbon nanotubes were synthesized and modified at 600, 700, and 800 °C. The results showed that the amount of sulfur doped in carbon nanotubes increased with the increase of temperature, which were 0.78%, 0.98%, and 1.07%, respectively, but the carbon/sulfur binding mode did not change. At the same time, sulfur doping significantly increased the specific surface area, which was conducive to improving the infiltration of the electrolyte into the electrode piece. Sulfur-doped carbon nanotubes are used as conductive agents for the cathode NCM523 of lithium-ion batteries, and compared with untreated carbon nanotubes, they effectively improve the battery polarization, reduce the internal resistance, and greatly improve the ratio performance, and in terms of cycling performance, the capacity retention rate of the battery is increased from 71.3% to 81~85%. [ABSTRACT FROM AUTHOR]

Designing well-organized and efficient nanoporous catalysts to enhance the efficiency of catalytic processes is a very intriguing and challenging area. In this study, a metal–organic framework (MOF) based on a novel porous nanocatalyst was prepared via a multistep post-synthetic modification approach. Initially, the Cr-MIL-101-NH2 was modified with cyanuric chloride and then melamine. Next, the modified MOF was used as the support for the immobilization of cobalt(II) ions by available functional groups, including amino and π–interactions of melamine and ligand on the surface of the modified MIL-101-NH2, to generate the MIL-101-NH2-CC/melamine@Co2+ catalyst. The structure and morphology of the catalyst were characterized using powder XRD, FTIR, FE-SEM, EDX, elemental mapping, TGA, and N2 adsorption–desorption isotherm analysis. The catalytic performance of MIL-101-NH2-CC/Melamine@Co2+ was evaluated by one-pot synthesis of 2,4,5-trisubstituted imidazole derivatives according to Debus–Radziszewski reaction from different aldehydes, benzil, and ammonium acetate under solvent-free conditions. Moreover, the MIL-101-NH2-CC/Melamine@Co2+ catalyst demonstrated significant catalytic activity in the methylene blue dye reduction, with a reduction time of 14 min and a rate constant (k1) of 0.0141 min−1. The catalyst was recycled and reused five and eight times in synthesizing 2,4,5-trisubstituted imidazole and the reduction reaction with appropriate catalytic activity. [ABSTRACT FROM AUTHOR]

By exploiting coordination‐driven self‐assembly, high yields of two 818 molecular metalla‐knots could be obtained using a thiazole‐moiety‐containing asymmetric dipyridyl ligand 2‐(pyridin‐4‐yl)‐5‐(pyridin‐4‐ylethynyl)benzo[d]thiazole (L1), as confirmed using X‐ray crystallographic analysis, electrospray ionization‐time‐of‐flight/mass spectrometry (ESI‐TOF/MS), and detailed liquid‐state nuclear magnetic resonance (NMR) spectroscopy. To modulate the self‐assembled structures, m‐chloroperbenzoic acid (m‐CPBA) was utilized to oxidize thiazole‐based ligand L1 to N‐thiazole‐oxide‐based ligand 2‐(pyridin‐4‐yl)‐5‐(pyridin‐4‐ylethynyl)benzo[d]thiazole 3‐oxide (L2), which enabled the selective construction of the corresponding tetranuclear macrocycles. Notably, two molecular metalla‐knots could be topologically transformed from 818 knots to simple monocycles because the L1 alkyne bond was inert toward m‐CPBA, as confirmed by liquid‐state NMR spectroscopy, ESI‐TOF/MS, and elemental analysis. [ABSTRACT FROM AUTHOR]

• Organic molecules can be covalently modified into the framework of Zr-MOF through the post-synthesis modification. • The abilities of visible-light harvesting and CO 2 capture for Zr-MOF can be regulated by the different functional groups. • Elucidation on the effects of the different functional groups on the photocatalysis. • The electron-donating groups in Zr-MOF dramatically enhances the photocatalytic activity. The reduction of CO 2 into high value-added chemicals and fuels by a photocatalytic technology can relieve energy shortages and the environmental problems caused by greenhouse effects. In the current work, an amino-functionalized zirconium metal organic framework (Zr-MOF) was covalently modified with different functional groups via the condensation of Zr-MOF with 2-pyridinecarboxaldehyde (PA), salicylaldehyde (SA), benzaldehyde (BA), and trifluoroacetic acid (TA), named Zr-MOF-X (X = PA, SA, BA, and TA), respectively, through the post-synthesis modification. Compared with Zr-MOF and Zr-MOF-TA, the introduction of PA, SA, or BA into the framework of Zr-MOF can not only enhance the visible-light harvesting and CO 2 capture, but also accelerate the photogenerated charge separation and transfer, thereby improving the photocatalytic ability of Zr-MOF for CO 2 reduction. These results indicate that the modification of Zr-MOF with electron-donating groups can promote the photocatalytic CO 2 reduction. Therefore, the current work provides an instructive approach to improve the photocatalytic efficiency of CO 2 reduction through the covalent modification of MOFs. [Display omitted] [ABSTRACT FROM AUTHOR]

The integration of organic and inorganic materials has been widely used in various applications to generate novel functional nano-materials characterized by unique properties. Functional crystalline framework nanosheets and their synergistic effects have been studied recently for possessing the advantages of functional species as well as crystalline framework nanosheets. Hence, we have focused on the preparation methods and applications of functional crystalline framework nanosheets in this review. We introduced crystalline framework nanosheets and discussed the importance of integrating functional species with nanosheets to form functional crystalline framework nanosheets. Then, two aspects of the preparation methods of functional crystalline framework nanosheets were reviewed: in situ synthesis and post-synthesis modification. Subsequently, we discussed the properties of the crystalline framework nanosheets combined with various functional species and summarized their applications in catalysis, sensing, separation, and energy storage. Finally, we have shared our insights on the challenges of functional crystalline framework nanosheets, hoping to contribute to the knowledge base for optimizing the preparation methods, expanding categories, improving stability, and exploring potential applications. [ABSTRACT FROM AUTHOR]

Traditional macrocyclic molecules encode recognition sites in their structural backbones, which limits the variation of the recognition sites and thus, would restrict the adjustment of recognition properties. Here, we report a new oligoamide-based macrocycle capable of varying the recognition functional groups by post-synthesis modification on its structural backbone. Through six steps of common reactions, the parent macrocycle (9) can be produced in gram scale with an overall yield of 31%. The post-synthesis modification of 9 to vary the recognition sites are demonstrated by producing four different macrocycles (10–13) with distinct functional groups, 2-methoxyethoxyl (10), hydroxyl (11), carboxyl (12) and amide (13), respectively. The 1H NMR study suggests that the structure of these macrocycles is consistent with our design, i.e., forming hydrogen bonding network at both rims of the macrocyclic backbone. The 1H-1H NOESY NMR study indicates the recognition functional groups are located inside the cavity of macrocycles. At last, a preliminary molecular recognition study shows 10 can recognize n-octyl-β-D-glucopyranoside (14) in chloroform. [ABSTRACT FROM AUTHOR]

For selectively sensing Tryptophan(Trp), the fluorescent Tb3+@UiO-66-(COOH)2 was prepared through loading Tb3+ into UiO-66-(COOH)2 via post-synthesis method. Transmission electron microscope (TEM), X-ray powder diffractometer (XRD), specific surface area analyzer, and X-ray photoelectron spectroscope (XPS) were used to analysize the morphology, composition and pore characteristics of the porous materials. Meanwhile, ultraviolet-visible spectrophotometer (UV-Vis) and fluorescence spectrophotometer were used to study the fluorescence characteristics. The results show that the energy transfer from organic ligand to Tb3+ leads to a bright green fluorescence. Among the 13 amino acids, only Tryptophan has obvious fluorescence quenching effect. This is because there appears a large overlap between UV-Vis absorption spectrum of Trp and excitation spectrum of the MOF, which indicates a strong competition effect for UV light. The absorption to UV light of Tb3+@UiO-66-(COOH)2 is decreased by Trp,leading to the weak fluorescence. Further investigation indicates the material can sensitively sense Trp (LOD, 5.53 μmol/L) and owns excellent anti-interference ability from other co-existing amino acids. Thus, this work not only demonstrates Tb3+@UiO-66-(COOH)2 can serve as a selective and sensitive sensor for Trp, but also provides a guideline for designing novel sensors for amino acids in the future.

With the advancement of nuclear energy, the safe disposal of radioactive materials, especially nuclear waste containing iodine, has become a serious issue attracting attention. Thus, reported here is a general strategy for creating a cationic covalent organic framework (TAPT-COF-AB) containing a significant number of free bromide ions through post-synthesis modification of a hydroxy-functionalized COF (TAPT-COF-OH) and exploration of the ionic covalent organic frameworks (iCOFs) for iodine adsorption. Owing to TAPT-COF-AB retaining good crystallinity and large BET surface area, it exhibits excellent adsorption capacity for iodine with a maximum adsorption capacity of up to 5.05 g/g. The results indicate an increase of 1.44 g/g compared to TAPT-COF-OH (3.61 g/g) and maintained its high performance even after five cycles. Furthermore, the calculation of density functional theory (DFT) shows the significant chemical interaction between iodine and the material frameworks and supports the accuracy of the experiment. The results performed that including ionic groups increased the affinity between COFs and iodine, thereby enhancing the iodine adsorption properties. This work opens an avenue for constructing functional COFs for environmentally relevant critical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Traditional macrocyclic molecules encode recognition sites in their structural backbones, which limits the variation of the recognition sites and thus, would restrict the adjustment of recognition properties. Here, we report a new oligoamide-based macrocycle capable of varying the recognition functional groups by post-synthesis modification on its structural backbone. Through six steps of common reactions, the parent macrocycle (9) can be produced in gram scale with an overall yield of 31%. The post-synthesis modification of 9 to vary the recognition sites are demonstrated by producing four different macrocycles (10–13) with distinct functional groups, 2-methoxyethoxyl (10), hydroxyl (11), carboxyl (12) and amide (13), respectively. The 1H NMR study suggests that the structure of these macrocycles is consistent with our design, i.e., forming hydrogen bonding network at both rims of the macrocyclic backbone. The 1H-1H NOESY NMR study indicates the recognition functional groups are located inside the cavity of macrocycles. At last, a preliminary molecular recognition study shows 10 can recognize n-octyl-β-D-glucopyranoside (14) in chloroform.

The post-synthesis modification is a highly efficient method for the modification of Metal-organic framework (MOF) materials, which has been used to synthesize MOF materials purposefully that cannot be prepared by direct synthesis and impregnation method. In this work, amino modified ZIF8 with 5-aminotetrazole was prepared by the post synthesis modification method and was employed to reversibly remove SO2 from flue gas. Based on the characterization and analysis of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and Brunner Emmet Teller (BET), it was found that the functionalized ZIF8 (Zn(5-ATZ)1.5) was a microporous material with a two-dimensional nano-layered structure. According to the SO2 adsorption experiments, the adsorption capacity of SO2 at the concentration of 1.6% vol can reach to 122 mg/g under the optimal conditions (25 °C, 2865 h−1). Five successive adsorption-desorption experiments exhibited that Zn(5-ATZ)1.5 had excellent regeneration performance. The characterization results of Raman Spectra (Raman) and X-ray photoelectron spectroscopy (XPS) as well as the DFT simulation calculations revealed that SO2 mainly interacted with Zn(5-ATZ)1.5 by hydrogen bonds between O of SO2 and amino H in the Zn(5-ATZ)1.5, and the interaction of SO2 with amino N and 5-aminotetrazole N by forming a non-covalent charge transfer complex. This work suggested that Zn(5-ATZ)1.5 is an excellent potential sorbent for SO2 removal. [ABSTRACT FROM AUTHOR]

[Display omitted] Herein, we propose a new strategy for designing new types of wide range p H-sensitive metal-organic frameworks (MOFs) with double luminescent centers on UiO-66-2OH. The UiO-66-2OH has a ligands-based emission at 530 nm. To introduce another luminescent center, PMA (1,2,4,5-benzenetetracarboxylic acid), as the functional site, is used to substitute the initial ligand, BDC-2OH (2,5-dihydroxyterephthalic acid), of UiO-66-2OH. Eu3+ ions, another luminescent center at 613 nm, are coordinated to the free carboxyl group on PMA. Finally, TTA (2-Thenoyltrifluoroacetone) is coordinated with Eu3+ ions to balance the emission at 613 nm (Eu3+ ions) and 530 nm (BDC-2OH). For the sake of both strong emissions, we explored the loading levels of PMA. The optimized structure is Eu(TTA)@MUM5 ("MUM" is the abbreviation of "Mixed ligand UiO-66-2OH MOFs" and "5" represents the molar percentage of PMA is 50%), which exhibits strong emission at 530 nm (alkaline solution) and 613 nm (neutral solution). Remarkably, the synthesized material has an exponential relationship (R 2 = 0.9973) over the p H range of 1.87 to 9.65 and a linear relationship (R 2 = 0.9987) when p H = 11.01–13.35. Further experiments have proved that Eu(TTA)@MUM5 could distinguish different amino acids. Based on that, we build an information transferring circle with two coding modes on Eu(TTA)@MUM5 using aseptic acid and arginine as coding factors. [ABSTRACT FROM AUTHOR]

Mesoporous silica of SBA-15 type was modified for the first time with 3-(trihydroxysiyl)-1-propanesulfonic acid (TPS) by post-synthesis modification involving microwave or conventional heating in order to generate the Brønsted acidic centers on the material surface. The samples structure and composition were examined by low temperature N2 adsorption/desorption, XRD, HRTEM, elemental and thermal analyses. The surface properties were evaluated by esterification of acetic acid with n-hexanol used as the test reaction. A much higher efficiency of TPS species incorporation was reached with the application of microwave radiation for 1 h than conventional modification for 24 h. It was found that the structure of mesoporous support was preserved after modification using both methods applied in this study. Materials obtained with the use of microwave radiation showed a superior catalytic activity and high stability. [ABSTRACT FROM AUTHOR]

A Cp*‐Rh based D‐shaped binuclear metallacycle and a template‐free molecular Borromean ring (BR) were obtained in high yield using the semi‐rigid thioether dipyridyl ligand 1,4‐bis[(pyridin‐4‐ylthio)methyl]benzene (Bptmb). The topological transformation from a binuclear metallacycle and a BR to tetranuclear metallacycles was realized via the controlled oxidation of thioethers. The strategy used in this work can be regarded as a new form of stimuli‐responsive post‐synthesis modification (PSM). [ABSTRACT FROM AUTHOR]

The field of post‐synthesis modification has aroused widespread concern from diverse perspectives, including chemistry, biology, and material science. Post‐synthesis modification can introduce rich functionality into metal–organic frameworks (MOFs) without destroying the main structure of MOFs. Based on this research status, a series of lanthanide metal–organic frameworks ([Ln2(NH2‐BDC)2.5(CH3COO)(DMA)(H2O)]•DMA, Ln = Pr, Nd, Sm, Eu, Gd and Tb, NH2‐BDC = 2‐aminoterephthalic acid, DMA = N,N‐Dimethylacetamide) with 3D network structures, are synthesized by hydrothermal synthesis. Due to the presence of uncoordinated amino groups in the ligands, a series of post‐synthesis modified compounds are successfully synthesized through aldimine condensation reaction. Based on the good fluorescence properties and stable structure of coordination polymers and post‐synthesis modified compounds in water or organic solvents, they are able to be used as potential fluorescence sensor for the detection of Th4+, UO22+, and Cr2O72−, and the calculation result shows that the post‐synthesis modified compounds are more sensitive to the detection of analytes (Th4+, UO22+ and Cr2O72−) than coordination polymers. In addition, the MOF membrane prepared by self‐assembly of [Eu2(NH2‐BDC)2.5(CH3COO)(DMA)(H2O)]•DMA and ternary soap‐free copolymer (VAc‐AA‐BA) emulsion can be used first for detecting aldehyde vapors. [ABSTRACT FROM AUTHOR]

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The efforts to achieve sustainable chemical conversion and efficient CO 2 utilization are critical to addressing climate change and environmental sustainability, and therefore the development of effective CO 2 conversion catalysts is crucial. In this study, novel acid-base bifunctional catalysts, MIL-101-SO 3 H@Atz and MIL-101-SO 3 H@DAtz, were successfully synthesized using MIL-101-SO 3 H as an acid support material through post-synthetic modification with 3-amino-1,2,4-triazole (Atz) and 3,5-diamino-1,2,4-triazole (DAtz) for CO 2 conversion reaction. The incorporation of the amine species into MIL-101-SO 3 H created unique synergistic effects with dual acid-base catalytic sites, facilitating the efficient conversion of CO 2 and epoxides into cyclic carbonates. Among the catalysts, MIL-101- SO3H@DAtz demonstrated superior catalytic performance with achieving 100% epichlorohydrin (ECH) conversion with over 99% selectivity to cyclic carbonate with high selectivity of > 99% under the ambient condition of 1 bar CO 2 without any co-catalyst or solvent. The elucidated CO 2 cycloaddition reaction mechanism highlights the synergistic effects of acid-base functionalities and CO 2 -philic Lewis bases as well as hydrogen bonding donor groups, providing valuable insights into the factors contributing to superior catalytic performance. The simulated flue gas (15% CO 2 /85% N 2 , v/v) was also conducted using MIL-101-SO 3 H@DAtz catalyst. Additionally, the MIL-101-SO 3 H@DAtz catalyst exhibited remarkably robust structural stability and recyclability, maintaining its activity over multiple cycles. [Display omitted] • Design and synthesis of site-isolated Lewis acid-Brønsted base bifunctional MIL-101-SO 3 H@DAtz catalyst. • Excellent catalytic activity of MIL-101-SO 3 H@DAtz for CO 2 cycloaddition at ambient pressure without co-catalyst. • Accelerating epoxide ring-opening by the isolation of catalytic sites in a single catalyst system. • MIL-101-SO 3 H@DAtz showed high structural stability and reusability during ten cycles. • A plausible reaction mechanism for CO 2 -epoxide cycloaddition was proposed. [ABSTRACT FROM AUTHOR]

Two metal–organic frameworks (MOFs) were prepared based on post-synthetic modification (PSM) method. To design advanced functional material with enhanced catalytic activity, Cu3(BTC)2 (H3BTC = benzene-1,3,5-tricarboxylate) was synthesized and functionalized with 4-aminopyridine and 2-pyridine carboxaldehyde to achieve a supported bidentate Schiff base. Then, molybdenyl acetylacetonate MoO2(acac)2 and vanadyl acetylacetonate VO(acac)2 were immobilized on Schiff base functionalized Cu3(BTC)2. These newly prepared catalysts were studied by powder X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), atomic absorption spectroscopy (AAS), field emission scanning electron microscopy (FE-SEM), and also N2 adsorption–desorption (BET method) analyses. After characterization, different parameters influencing the reaction were optimized. A comparative study of the catalytic activity was carried out in the epoxidation of various olefins and allylic alcohols over tert-butyl hydroperoxide (TBHP). The maximum conversion was achieved in the case of Mo-catalyst as an effective and selective catalyst in the epoxidation of allylic alcohols. [ABSTRACT FROM AUTHOR]

The post-synthesis modification is a highly efficient method for the modification of Metal-organic framework (MOF) materials, which has been used to synthesize MOF materials purposefully that cannot be prepared by direct synthesis and impregnation method. In this work, amino modified ZIF8 with 5-aminotetrazole was prepared by the post synthesis modification method and was employed to reversibly remove SO2 from flue gas. Based on the characterization and analysis of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and Brunner Emmet Teller (BET), it was found that the functionalized ZIF8 (Zn(5-ATZ)1.5) was a microporous material with a two-dimensional nano-layered structure. According to the SO2 adsorption experiments, the adsorption capacity of SO2 at the concentration of 1.6% vol can reach to 122 mg/g under the optimal conditions (25 °C, 2865 h−1). Five successive adsorption-desorption experiments exhibited that Zn(5-ATZ)1.5 had excellent regeneration performance. The characterization results of Raman Spectra (Raman) and X-ray photoelectron spectroscopy (XPS) as well as the DFT simulation calculations revealed that SO2 mainly interacted with Zn(5-ATZ)1.5 by hydrogen bonds between O of SO2 and amino H in the Zn(5-ATZ)1.5, and the interaction of SO2 with amino N and 5-aminotetrazole N by forming a non-covalent charge transfer complex. This work suggested that Zn(5-ATZ)1.5 is an excellent potential sorbent for SO2 removal.

Post‐synthesis modification of MIL‐101(Cr)‐NO2 was explored in order to decorate the organic backbone by propyl‐sulfonic groups, with the aim to incorporate mobile and acidic protons for solid‐state proton electrolyte applications. The resulting solid switched from insulating towards proton superconductive behavior under humidity, while the conductivity recorded at 363 K and 95 % relative humidity reached 4.8×10−3 S cm−1. Propitiously, the impregnation of the material by strong acidic molecules (H2SO4) further boosted the proton conductivity performances up to the remarkable σ value of 1.3×10−1 S cm−1 at 363 K/95 % RH, which reaches the performances of the best proton conductive MOF reported so far. [ABSTRACT FROM AUTHOR]

By exploiting coordination-driven self-assembly, high yields of two 8 18 molecular metalla-knots could be obtained using a thiazole-moiety-containing asymmetric dipyridyl ligand 2-(pyridin-4-yl)-5-(pyridin-4-ylethynyl)benzo[d]thiazole (L 1 ), as confirmed using X-ray crystallographic analysis, electrospray ionization-time-of-flight/mass spectrometry (ESI-TOF/MS), and detailed liquid-state nuclear magnetic resonance (NMR) spectroscopy. To modulate the self-assembled structures, m-chloroperbenzoic acid (m-CPBA) was utilized to oxidize thiazole-based ligand L 1 to N-thiazole-oxide-based ligand 2-(pyridin-4-yl)-5-(pyridin-4-ylethynyl)benzo[d]thiazole 3-oxide (L 2 ), which enabled the selective construction of the corresponding tetranuclear macrocycles. Notably, two molecular metalla-knots could be topologically transformed from 8 18 knots to simple monocycles because the L 1 alkyne bond was inert toward m-CPBA, as confirmed by liquid-state NMR spectroscopy, ESI-TOF/MS, and elemental analysis., (© 2023 Wiley-VCH GmbH.)

The oligomerisation of light olefins, obtainable from fossil/renewable sources and refinery streams, is an attractive route to produce clean synthetic fuels and added‐value chemicals. ZSM‐5 is a type of catalyst used in commercial olefin oligomerisation processes. Using appropriate modification procedures, it was possible to prepare catalysts with improved performances. Various modified versions of commercially available ZSM‐5 were prepared and investigated for 1‐butene oligomerisation under high‐pressure, continuous‐flow operation (30 bar, 200 °C). Simple, up‐scalable top‐down strategies involving base‐acid treatments of ZSM‐5 led to catalysts possessing enlarged pores and the required acidity for converting 1‐butene to higher molar mass products. In targeting diesel type products, the modified catalysts led to up to 86 % butenes conversion, space time yield of 852 mg gcat−1 h−1 and mass ratio diesel:naphtha cuts of 2.2. Characterisation studies and multivariate/principal component analysis helped categorise the differently prepared catalysts, and gain insights into complex interplay of material properties influencing the catalytic reaction. [ABSTRACT FROM AUTHOR]

Abstract Commercial Beta zeolite (Si/Al = 19) was treated with aqueous solutions of hexadecyltrimethylammonium (CTA) in the presence of NaOH or NH 4 OH to generate hierarchical porosity in the material. The combination of a basic media and surfactant (CTA) allows generation of mesoporosity while preserving the crystallinity and acidity of the parent Beta zeolite. In addition, characterization by XRD and TEM gave no evidence for the formation of segregated mesoporous phases. TEM and N 2 adsorption isotherms suggest the presence of substantial intracrystalline mesoporosity (average pore size of 3 nm) in the Beta zeolite crystals, which was more pronounced for samples treated with CTA/NaOH solutions. The concentration of total Brønsted acid sites was determined by pyridine adsorption, and it increased in the treated samples as compared with the parent Beta zeolite. The strongest Brønsted acid sites slightly increased for the CTA/NH 4 OH sample, while they decreased when ammonium hydroxide was replaced by NaOH. All these results indicate that the basic character (i.e. strength) of the aqueous solution affects the degree of the zeolite mesostructuring process. The activity of the treated samples in the isomerization-disproportionation (I-D) of m-xylene was related to the concentration of the strongest Brønsted acid sites. The treatment with sodium hydroxide or ammonia aqueous solutions led to an I/D ratio lower than that of the parent Beta zeolite, evidencing the benefits of the additional mesoporosity by enhancing the formation of the bulkiest bimolecular intermediate required to form disproportionation products. Graphical abstract Image 1 Highlights • Zeolite Beta containing intracrystalline mesopores has been obtained by a post-synthesis methodology. • Time and nature of alkaline solution affects the surfactant incorporation to generate mesoporosity. • Crystallinity and Si/Al ratio was preserved after hierarchical material was obtained by post-synthesis treatment. [ABSTRACT FROM AUTHOR]

Here, we report a post-synthesis functionalization of the shell of Au nanoclusters (NCs) synthesized using glutathione as a thiolate ligand. The as-synthesized Au NCs are subjected to the post-synthesis functionalization via amidic coupling of dopamine on the cluster shell to tailor photoluminescence (PL) and electrochemiluminescence (ECL) features of the Au NCs. Because the NCs’ PL at ca. 610 nm is primarily ascribed to the Au(I)-thiolate (SG) motifs on the cluster shell of the NCs, the post-synthesis functionalization of the cluster shell enhanced the PL intensity of the Au NCs via rigidification of the cluster shell. In contrast to the PL enhancement, the post-synthesis modification of the cluster shell does not enhance the near-infrared (NIR) ECL of the NCs because the NIR ECL at ca. 800 nm is ascribed to the Au(0)-SG motifs in the metallic core of the NCs.

The construction of hierarchical pore systems from the post-synthesis modifications of lamellar zeolite catalysts have attracted wide interests to solve the diffusion limitations in the catalytic application of zeolite catalysts. Herein, the interlayer expanded MWW with different interlayer spacing were obtained, based on the post-synthesis modifications of a swollen multilamellar MWW precursor, in which the MWW layers were pillared by cetyltrimethylammonium bromide (CTAB) surfactant with 25 Å interlayer distance. The direct calcination and the post-synthesis modifications led to zeolite catalysts with more open pore structures (hierarchical, interlayer expanded and pillared), which were evidenced by a series of characterizations, such as PXRD, TEM, N 2 adsorption-desorption etc. Moreover, the catalytic performances of the hierarchical MWW (H-MWW), interlayered expanded zeolite IEZ-MWW and Pillared-MWW catalysts were compared with 3D-MWW and ZSM-5 in the condensation of cyclohexanone with glycol or benzaldehyde with 1-pentanol. The catalysts prepared in this study show better catalytic activities than 3D-MWW and ZSM-5. [ABSTRACT FROM AUTHOR]

[Display omitted] • A post-synthesis modification strategy to prepare optically active chiral COFs. • COF Dha Tab-3 exhibited highly fluorescent property and chiral property. • Rapid chiral recognition for imazamox enantiomers was developed by COF Dha Tab-3. • COF Dha Tab-3 showed sensitive enantioselectivity to imazamox in five pesticides. We report a post-synthesis modification for the preparation of a novel chiral fluorescent covalent organic framework (COF) for selective recognization of imazamox enantiomers. In this study, chiral COF was firstly synthesized via a Schiff-base reaction between 2,5-dihydroxyterephthalaldehyde (Dha) and 1,3,5-tris(4-aminophenyl)benzene (Tab) followed by a nucleophilic substitution using (1S)-(+)-10-camphorsulfonyl chloride as chiral modifier. The resulting regular spherical chiral COF Dha Tab not only presented the high optical efficiency, strong covalent bond structure, good crystallinity, large specific surface area but also showed the specific enantioselectivity and quick identification for imazamox enantiomers among five pesticide enantiomers (S/R-imazamox, acephate, acetochlor, propisochlor and metalaxyl). The detection limits for S- and R-imazamox were 4.20 μmol/L and 3.03 μmol/L, respectively. Meanwhile, the enantiomeric excess value (5.30 %) manifested that the chiral COF Dha Tab had the strong adsorption ability to imazamox enantiomers and more higher affinity for R-imazamox. This chiral fluorescent COF opened up a new way for the recognition of enantiomers. [ABSTRACT FROM AUTHOR]

The concept of a Structurally Tailored and Engineered Macromolecular gel (STEM gel) is presented. A STEM gel is comprised of a network with latent initiating sites allowing for the post-synthesis, spatially specific modification of the matrix. A direct synthetic method was employed and photo-active STEM gels based on (meth)acrylates were synthesized by free radical copolymerization of different monomers, a crosslinker, and a photo-active dormant initiator/monomer (inimer) based on the radical photoinitiator 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959). Infiltration by a solution of a crosslinker was followed by the UV triggered polymerization of secondary polymeric chains. Irradiation through masks with different transmittance resulted in materials with spatially differentiated mechanical properties. [ABSTRACT FROM AUTHOR]

Post-synthesis modification is a useful method for the functionalization of metal-organic frameworks (MOFs). A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde), containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101) were prepared successfully by the impregnationmethod. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption-desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9) and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs. [ABSTRACT FROM AUTHOR]

Transition metal hexacyanocobaltates are porous materials with open metal sites and a wide variety of pores. In this work, manganese(II) and cobalt(II) hexacyanocobaltates(III) have been selected to explore the interactions between the open metal sites located in their pores and the guest molecules: hydrogen, carbon dioxide, water and methanol. An experimental setup was designed and implemented to conduct post-synthesis modification of the solids with ozone. Samples were dehydrated, ozonized and saturated with methanol in situ. Ozone molecules acted on the open metal sites changing their oxidation state, causing a contraction of the unit cell and inducing a stronger interaction of the molecules of water and methanol with the lattice. This strengthening prevented the lattice from being evacuated without compromising its framework stability. The decomposition temperature decreased in all ozonized samples as a consequence of the elongation and weakening of the cobalt-carbon bond. Active infrared and Raman bands were used to monitor the interaction between the open metal sites at the framework surface and the guest molecules. The cell contraction and the presence of residual methanol molecules in the porosity reduced the hydrogen and carbon dioxide retention capacity of the samples. [ABSTRACT FROM AUTHOR]

Post-synthesis modification is an effective strategy for the preparation of rare earth organic framework materials and the derivation of high-performance functional materials. Here, we report the preparation of a dual emission Ln-MOF material (Eu-Ca-MOF) using Ca-MOF as the parent framework and introducing Eu3+ ions into its channels through post-synthesis modification. Eu-Ca-MOF has good photoluminescence properties and can be used as a ratiometric fluorescence sensor (I 381 /I 590) to detect Hg2+ ions in water sensitively. The characteristic of Eu-Ca-MOF obtained is that when the material is dispersed in an aqueous solution containing Hg2+ ions, the characteristic emission of the ligand at 381 nm is enhanced, while the characteristic emission of Eu3+ at 590 nm is quenched. The peak-to-height ratio of the two emissions can be used to achieve highly sensitive detection of Hg2+ ions even in the presence of other potentially competing analytes. In addition, Hg2+ induces Eu-Ca-MOF to produce a significant ratiometric luminescence response, which changes its luminescence color from red to blue, which is beneficial to visual analysis of naked eyes. At the same time, Eu-Ca-MOF has a wider detection range (0.02–200 μM), and a lower limit detection (2.6 nM) for Hg2+ ions. The lanthanide compounds prepared by post-synthetic modification provide an effective synthesis strategy for photoluminescent materials. [Display omitted] • A novel ratiometric fluorescent sensor Eu-Ca-MOF is prepared by post-synthesis modification. • The ratiometric fluorescence sensor is used for sensitive detection of Hg2+. • Significant color change under UV-lamp makes it adequate to visual analysis of Hg2+. • The post-synthetic modification is an efficient strategy for function-oriented MOFs design. [ABSTRACT FROM AUTHOR]

Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs). A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde), containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101) were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9) and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

Transition metal hexacyanocobaltates are porous materials with open metal sites and a wide variety of pores. In this work, manganese(II) and cobalt(II) hexacyanocobaltates(III) have been selected to explore the interactions between the open metal sites located in their pores and the guest molecules: hydrogen, carbon dioxide, water and methanol. An experimental setup was designed and implemented to conduct post-synthesis modification of the solids with ozone. Samples were dehydrated, ozonized and saturated with methanol in situ. Ozone molecules acted on the open metal sites changing their oxidation state, causing a contraction of the unit cell and inducing a stronger interaction of the molecules of water and methanol with the lattice. This strengthening prevented the lattice from being evacuated without compromising its framework stability. The decomposition temperature decreased in all ozonized samples as a consequence of the elongation and weakening of the cobalt-carbon bond. Active infrared and Raman bands were used to monitor the interaction between the open metal sites at the framework surface and the guest molecules. The cell contraction and the presence of residual methanol molecules in the porosity reduced the hydrogen and carbon dioxide retention capacity of the samples.

Herein, corncob waste was used as a scaffold for the fabrication of effective adsorbents. Porphyrinic zirconium metal-organic frameworks (MOFs) PCN-223 and PCN-224 constructed by different numbers of Zr6 cluster nodes were grown on the surface of the corncob. Fe (Ш) ions were implanted in the porphyrin ring by post-synthesis modification. The results showed that the extraction capacity of diuretics on PCN-224@corncob containing suitable pore size was larger than that of PCN-223@corncob. The adsorption of diuretics was further enhanced because of the electrostatic effect caused by implantation of Fe (Ш) ions. PCN-224-Fe@corncob was recyclable and selective for the extraction of furosemide (Fur) and bumetanide (Bum). Coupled in-syringe solid phase extraction (IS-SPE) with ultra-performance liquid chromatography (UPLC), an efficient, sensitive, and stable method was established. With a sensitivity between 0.6 and 1.0 μg/L and a recovery between 83.2% and 119.2%, it is used for the analysis of trace amounts of Fur and Bum in weight loss products and environmental water. The functionalized corncob has potential application for the adsorption of diuretics, and the metal ions implantation in MOFs provides a promising strategy for enhancing extraction capacity. [Display omitted] • PCN-223 and PCN-224 were grown on the surface of corncob by one pot reaction. • Post-synthesis modification was conducted to implant Fe (Ш) in the porphyrin ring. • PCN-224-Fe exhibited best extraction due to the pore size and electrostatic effects. • PCN-224-Fe@corncob was applied to the selective extraction of Fur and Bum. [ABSTRACT FROM AUTHOR]

Mesoporous saponites were prepared at pH 8 and 13 without and with template (surfactant or polymer) at 453 K and autogenic pressure using microwaves or conventional oven during the hydrothermal ageing treatment. Acidity was obtained by calcination of the NH 4 -form. The effect of dilution (H 2 O/Si molar ratios of 250, 125 and 50) was studied for the samples prepared at pH 8 with surfactant. In order to compare the effect of introducing surfactant during or after saponite synthesis, several samples prepared at pH 13 were modified after synthesis by refluxing or by stirring at room temperature in a surfactant solution. Preparation of samples at pH 13 favoured the ordering in the stacking direction, improved Al T /Al O ratio and led to samples with lower amorphous siliceous material content. The use of microwaves and surfactant for the synthesis at pH 13 afforded a saponite with the highest surface area (603 m 2 /g) and the smallest lamellae crystallite size (about 4 nm). The properties of the samples synthesized at pH 8 with surfactant depended on the dilution. Thus, the degree of delamination, the BET area and the Al T /Al O ratio increased whereas the amorphous siliceous material content decreased at lower slurry dilution. The incorporation of the surfactant by post-synthesis resulted in some degree of delamination especially when using refluxing. However, the degree of delamination was higher for the saponites prepared with the addition of the surfactant during the hydrothermal synthesis. [ABSTRACT FROM AUTHOR]

Creatinine (Cre) measurement in biological fluids is an increasingly important clinical measure for evaluating renal insufficiency, thyroid dysfunction, and muscle injury. Therefore, a simple, fast, and reliable Cre analysis method is of great significance to human health. Herein, a novel ratiometric fluorescence sensor, Ag-Eu-MOF-808-EDTA, was synthesized by introducing ethylenediaminetetraacetic acid (EDTA), Ag+, and Eu3+ into the framework of MOF-808 through three steps of post-synthesis modification, and was used to detect Cre in PBS buffer of pH 7.2 at 35 °C with a "turn-on" ratio response in the presence of various interfering ions and several biomolecules. In this strategy, the characteristic emission of Eu3+ at 551 nm can be turned on due to coordination between Cre and Ag+, while emission at 613 nm is independent of Cre, which produces a significant ratio response change throughout the cycle. Experimental results showed that the ratio fluorescence sensor displayed a wide linear range for Cre from 0.5 to 350 μM with a low detection limit of 0.42 μM. Finally, a good recovery rate (96.7–102.9%) and appropriate relative standard deviation (RSD <2.39%, n = 3) were obtained during the determination of creatinine in real urine and serum. This work provides additional insights into the detection of creatinine in clinical blood samples. [Display omitted] • Ag-Eu-MOF-808-EDTA was prepared by three-step post-synthetic modification. • The material was used for a ratiometric fluorescence sensing of creatinine. • The ratiometric sensor showed a wide linear range and low detection limit for Cre. [ABSTRACT FROM AUTHOR]

Abstract: A series of bimodal micro–mesoporous H/BEA zeolite derivatives were prepared by the post-synthesis modification of H/BEA zeolite by NaOH (0.05M–1.2M) treatment. Samples were characterized by powder XRD, low temperature nitrogen adsorption/desorption, temperature programmed desorption of ammonia and ICP. The mesopore formation was found to play a crucial role in liquid phase esterification of levulinic acid with ethanol. The enhanced catalytic activity of a bimodal micro–mesoporous H/BEA zeolite derivative (H/BEA0.10) prepared by treatment with 0.1M NaOH can be mainly attributed to the high mesoporosity coupled with better preserved crystallinity and acidic properties. [Copyright &y& Elsevier]

[Display omitted] • A new heterogeneous catalyst was synthesized for direct conversion of methane. • The synergistic effect between Pt and POM was used to enhance catalytic activity. • The conversion of methane to methanol, ethanol and acetic acid was realized. In this work, a novel heterogeneous compfosite catalyst was synthesized via the immobilization of platinum and polyoxometalate into MOFs containing bipyridine groups. The resulting UiO-67-Pt-Z has a high specific surface area (446 m2 g−1), which is beneficial to adsorb more methane molecules in the methane catalysed transformation, and the homogeneous distribution of Pt and POM can improve the catalytic efficiency of the catalyst. Under mild reaction conditions, methanol, ethanol, and acetic acid can be obtained in 2 h. Our work provides a new catalyst for the rapid catalytic oxidation of methane to high value-added oxygenates and broadens new ideas for exploring effective methane direct conversion in future work. [ABSTRACT FROM AUTHOR]

In this study, a novel type of covalent organic framework (COF) material rich in boronic acid sites was prepared through post-synthesis modification (TbBD@PEI@Au@4-MPBA). The surface of COF material had abundant carboxylic acid groups, which could bind a large amount of polyethyleneimine (PEI) through electrostatic interaction. At the same time, the amino groups on the PEI can be grafted with Au nanoparticles (Au NPs) in situ, and then 4-mercaptophenylboronic acid (4-MPBA) was modified by the reaction of Au and sulfhydryl groups. The massive grafting of boronic acid groups made the material's enrichment effect on glycopeptides expected. The results of experiments indicated that the composite material has high sensitivity (5 amol μL−1) and selectivity (1:1000). In addition, the material has outstanding stability and reusability, with a load capacity of about 100 mg g−1 and a recovery of 99.3 ± 2.2%. What's more, after enriched by TbBD@PEI@Au@4-MPBA, 56 endogenous glycopeptides from fresh human saliva were detected by MALDI-TOF MS, 56 unique glycopeptides corresponding to 31 glycoproteins from human saliva and 513 unique glycopeptides corresponding to 208 glycoproteins from serum of throat cancer patient were detected by nano-LC-MS/MS, respectively, which was expected to be applied to glycoproteomics research. [Display omitted] • A novel nanomaterial based post-synthesis modification was designed in order to enrich glycopeptides more efficiently. • The presence of PEI on the surface improved the hydrophilicity of COF and provided sites for the grafting of 4-MPBA. • The TbBD@PEI@Au@4-MPBA performed excellent in the glycopeptides enrichment, more than 513 glycopeptides from serum. [ABSTRACT FROM AUTHOR]

Abstract: Framework defect-free nanosized silicalite-1 crystals (ca. 150nm) have been obtained by post-synthesis modification of a zeolite prepared under alkaline pH conditions. Several methods have been proposed, all of them being based on dissolution/recrystallization processes that keep the size of the zeolite crystals unchanged. Treatment of as-made zeolites with NH4F led to a significant decrease in the density of siloxy framework defects but silanol groups could not be totally eliminated, even after calcination. On the other hand, a succession of treatments in TPAOH and NH4F led to materials with very few framework defects and more or less regular hollow structures. The best solids were obtained when treatments were performed on calcined zeolites with solid NH4F. Under such conditions, zeolites were first dissolved following a mechanism similar to that observed under alkaline pH conditions but hollow structures thus obtained could not be stabilized and they progressively disappeared with time. Despite that, the crystallinity remained unaltered and treated zeolites were characterized by highly resolved 29Si NMR spectra, characteristic of defect-free all-silica frameworks. Modifications of the crystal shape with time have been explained by a partial recrystallization of the zeolite in the presence of ammonium ions. [Copyright &y& Elsevier]

Post-synthesis modification of DNA is an important way of functionalizing DNA molecules. Herein, we describe a method that first enzymatically incorporates a cyanobenzothiazole (CBT)-modified thymidine. The side-chain handle CBT can undergo a rapid and site-specific cyclization reaction with 1,2-aminothiols to afford DNA functionalization in aqueous solution. Another key advantage of this method is the formation of a single stereo/regioisomer in the process, which allows for precise control of DNA modification to yield a single component for aptamer selection work and other applications. [ABSTRACT FROM AUTHOR]

The known MOF UiO-67 of general formula [Zr6O4(OH)4(bpdc)6] [bpdc = biphenyldicarboxylate, O2C(C6H4)2CO2] has been synthesized on a 3 g scale and characterized by BET, TGA, XRD, IR and 13C NMR spectroscopy, and elemental analyses. The chemical accessibility of the hydroxy ligand Zr3(μ-OH) was assessed by the addition of D2O: The expected isotopic shift of ν(OH) = 3673 cm-1 to ν(OD) = 2709 cm-1 in the IR spectrum was observed. The OH content in bulk UiO-67, previously mildly activated at 120 °C under vacuum (10-5 Torr) overnight, was quantitatively determined by three methods: (1) By integration of the IR ν(OH) region and comparison with calibrated spectra of MCM-41 previously dehydroxylated at 500 °C, which gave a spectroscopically measured OH content in bulk UiO-67 of 2.2 mmol/g (37 mg OH/g); (2) by extrapolation of the OH content from the measured weight loss between 250 and 400 °C in TGA, which corresponded to 1.6 mmol OH/g (27 mg OH/g); and (3) by chemical titration of UiO-67 with CH3MgBr and GC determination of the evolved methane, which gave 1.8 mmol OH/g (31 mg OH/g). The three methods, and in particular the latter chemical titration, are in very good to excellent agreement with the nominal OH content based on the molecular formula [Zr6O4(OH)4(bpdc)6] (expected: 1.9 mmol OH/g, 32 mg OH/g; experimental/calculated OH content = 110, 85, and 95 %, respectively, for the three methods). The weak acidity of the OH moiety in UiO-67 was assessed by IR and 31P NMR monitoring of the physisorption of PMe3 in the UiO-67 cavities. Inclusion of the organometallic AuI complex [AuMe(PMe3)] in a 1:1 molar ratio with respect to [Zr6O4(OH)4(bpdc)6] was achieved. Some chemisorption at 20 % of the cornerstone hydroxy sites also occurred to yield [Zr6O4(OH)3(bpdc)6(OAuPMe3)]. [ABSTRACT FROM AUTHOR]

The known MOF UiO-67 of general formula [Zr6O4(OH)4(bpdc)6] [bpdc = biphenyldicarboxylate, O2C(C6H4)2CO2] has been synthesized on a 3 g scale and characterized by BET, TGA, XRD, IR and 13C NMR spectroscopy, and elemental analyses. The chemical accessibility of the hydroxy ligand Zr3(μ-OH) was assessed by the addition of D2O: The expected isotopic shift of ν(OH) = 3673 cm-1 to ν(OD) = 2709 cm-1 in the IR spectrum was observed. The OH content in bulk UiO-67, previously mildly activated at 120 °C under vacuum (10-5 Torr) overnight, was quantitatively determined by three methods: (1) By integration of the IR ν(OH) region and comparison with calibrated spectra of MCM-41 previously dehydroxylated at 500 °C, which gave a spectroscopically measured OH content in bulk UiO-67 of 2.2 mmol/g (37 mg OH/g); (2) by extrapolation of the OH content from the measured weight loss between 250 and 400 °C in TGA, which corresponded to 1.6 mmol OH/g (27 mg OH/g); and (3) by chemical titration of UiO-67 with CH3MgBr and GC determination of the evolved methane, which gave 1.8 mmol OH/g (31 mg OH/g). The three methods, and in particular the latter chemical titration, are in very good to excellent agreement with the nominal OH content based on the molecular formula [Zr6O4(OH)4(bpdc)6] (expected: 1.9 mmol OH/g, 32 mg OH/g; experimental/calculated OH content = 110, 85, and 95 %, respectively, for the three methods). The weak acidity of the OH moiety in UiO-67 was assessed by IR and 31P NMR monitoring of the physisorption of PMe3 in the UiO-67 cavities. Inclusion of the organometallic AuI complex [AuMe(PMe3)] in a 1:1 molar ratio with respect to [Zr6O4(OH)4(bpdc)6] was achieved. Some chemisorption at 20 % of the cornerstone hydroxy sites also occurred to yield [Zr6O4(OH)3(bpdc)6(OAuPMe3)]. [ABSTRACT FROM AUTHOR]

Abstract: Novel modified “chemisorption–hydrolysis” technique and conventional “incipient wetness impregnation” procedure were compared for loading of cobalt species on mesoporous silica supports. Effect of cobalt amount, pH of the precursor solution, duration of the “chemisorption” procedure and pre-treatment medium, as well as topological characteristics of the mesoporous silica support were investigated. The state of the loaded cobalt species was studied by XRD, FTIR, FTIR of adsorbed pyridine, UV–vis, XPS and TPR methods and their catalytic properties were elucidated in methanol decomposition to hydrogen and carbon monoxide. The “incipient wetness impregnation” technique facilitates the formation of finely dispersed spinel cobalt oxide species. Their catalytic activity could be significantly increased by hydrogen pretreatment, but the effect is more pronounced when mesoporous silica with ordered pseudo 1D pore structure (SBA-15) is used as a support. The modified “chemisorption–hydrolysis” procedure facilitates the formation of strongly interacting with the support cobalt species, which are stable under the reduction conditions. Their properties could be regulated during the modification procedure, by varying the cobalt content and pH of the impregnated solution as well as by the duration of the “chemisorption” procedure. [Copyright &y& Elsevier]

Abstract: Copper modifications of ordered mesoporous materials with different pore topology (SBA-15 and KIT-6) were prepared by incipient wetness impregnation and “chemisorption–hydrolysis” methods and further oxidative or consecutive oxidative/reductive treatment. The samples were characterized by nitrogen physisorption, XRD, XPS, FTIR, UV–vis and TPR–TG techniques. The ordered structures and the “chemisorption–hydrolysis” post synthetic method provide the formation of homogeneously dispersed in the mesopores copper species. The “chemisorption–hydrolysis” modification of the silicas with more opened 3D ordered structure (KIT-6) provides the formation of highly active catalysts, but their activity could be easily suppressed after the treatment under the reduction medium. [Copyright &y& Elsevier]

Abstract: Zeolite beta crystals (Si/Al=35) synthesized in fluoride medium were treated in aqueous 0.2M NaOH solution for mesopore formation by selective extraction of framework silicon. A 16 parallel-batch reactor was used to study the influence of the treatment time and temperature on the physico-chemical properties of the zeolites, which were characterized by ICP-OES, XRD, N2 adsorption at 77K, SEM, TEM, DRIFTS, and in situ ATR-IR. Alkaline treatment of H-beta within the optimal window of Si/Al ratios identified for other zeolite families leads to extensive silicon extraction at mild treatment conditions. This originates substantial mesoporosity and presumably improved transport, but negatively impacts on the microporous and acidic properties of the resulting sample. Consequently, the alkaline-treated beta zeolites show lower catalytic activity in the acid-catalyzed liquid-phase benzene alkylation than the purely microporous parent material. The relatively low stability of framework aluminum in BEA, compared to MFI and MOR, is detrimental for the controlled mesopore formation by Si dissolution, since aluminum cannot optimally exert its pore-directing role. [Copyright &y& Elsevier]

Abstract: Alkaline treatment of Fe-ZSM-5 zeolite induces substantial intracrystalline mesoporosity and enhances the population of isolated Fe3+ at the expense of oligonuclear clusters. In situ UV/vis showed that this redispersion affects the redox properties of the alkaline-treated zeolite and leads to lower activity in direct N2O decomposition compared with the parent sample. Subsequent ion exchange of the alkaline-treated sample in ammonium nitrate solutions induced a renewed alteration in iron speciation, resulting in a similar constitution as in the parent zeolite but with a higher concentration of Fe2+ sites able to activate N2O. Mechanistic investigations in the TAP reactor furthermore affirmed that these newly obtained species had improved oxygen desorption, which correlates with the superior activity in direct N2O decomposition. [Copyright &y& Elsevier]

Pt-supported on mesoporous SBA-15 catalysts (Pt/SBA-15) have been investigated for selective catalytic reduction of NO by propene in excess oxygen. Catalytic activity of Pt/SBA-15 can be improved by the post-synthesis modification of Al into SBA-15. The resulting material (AlSBA-15) retains a hexagonal order and physical properties of the parent SBA-15 and shows new acid sites. Increased acid sites are confirmed by NH3-TPD. Medium acid site appeared at 200 °C and broad strong acid site appeared above 250 °C. A certain degree of support acidity of Pt/AlSBA-15 increased the NO conversion, but when there are too many acid sites, carbon deposition becomes extensive and lead to decrease the NO conversion. The influence of different Pt loadings on the catalytic properties was also investigated. [ABSTRACT FROM AUTHOR]