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MIL-101(Cr) has demonstrated promising potential for tetracycline (TC) adsorption owing to its exceptional water stability. In this study, polymers with nitrogenous organic ligands were incorporated in the framework of MIL-101(Cr) using a post-synthetic modification approach to enhance the adsorption properties of MIL-101(Cr) for TC. We used the grafting reagent 4-aminopyridine (4-Apy), which contains two types of nitrogen species (amino nitrogen and pyridine nitrogen), to create a series of stable MOF composite materials, xApy-MIL-101(Cr), through interaction with the exposed Cr(III) sites in MIL-101(Cr). The high nitrogenous organic ligand content in the framework of xApy-MIL-101(Cr) contributes to its high TC adsorption capacity. The results showed that 30%Apy-MIL-101(Cr) adsorbed far more than MIL-101(Cr), reaching a maximum adsorbed amount of 264.5 mg g−1, nearly five times greater. Importantly, adsorption equilibrium can be reached within 50 minutes. Moreover, the primary adsorption mechanisms of xApy-MIL-101(Cr) for TC removal involve hydrogen bonding, π–π interactions, and electrostatic interactions. Additionally, 30%Apy-MIL-101(Cr) demonstrated excellent adsorption cycle stability, maintaining a regeneration rate of 74% even after four cycles of TC adsorption and desorption. [ABSTRACT FROM AUTHOR]

Determining the effect of crystal facets on reaction performance is essential for designing an efficient propane oxidation catalyst. Herein, α-MnO2 nanowires with exposed (110), (211), (310) and (200) facets were proposed, and their crystal facet-dependent reactivity to propane oxidation was investigated. The resultant α-MnO2 nanowires with predominantly exposed (110) facets showed the maximum propane oxidation activity (T90 = 262.1 °C), oxidation rate, and turnover frequency (at 230 °C), and high stability during the oxidation of propane. In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that the oxidation to form carboxylates is the decisive step; therefore, the production of reactive oxygen species is very important. The results from density of states computations revealed that the lowest electron energy was present in the (110) facet, which helps in the generation of reactive oxygen species and the regulation of the surface valence of Mn. The characterization and calculation results indicated that the (110) facets are conducive to forming oxygen vacancies, which allowed the activation and adsorption of O2 and propane, resulting in significantly enhanced propane oxidation activity. Apart from offering new insights about the structure–activity relationship of α-MnO2 with different facets exposed for short-chain volatile oxidation reactions, this study proposes a technique that can be used for improving other manganese-based catalyst oxidation systems. [ABSTRACT FROM AUTHOR]

The simultaneous shaping and confinement of Cu-based MOP in alginate-SiO2 spheres significantly enhance the mechanical strength and leaching resistance of Cu-MOP. The resulting MOP-alginate-SiO2 is shown through chemical fixation of CO2 to exhibit improved product yield over the parent Cu-MOP and Cu-alginate-SiO2. [ABSTRACT FROM AUTHOR]

A highly efficient solid-amine adsorbent with excellent CO2 capacity from flue gas was successfully prepared using polyethyleneimine (PEI)-impregnated resin HPD450 in this study. The adsorbents were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), N2 adsorption–desorption, thermogravimetric analysis (TGA) techniques and elemental analysis (EA). The CO2 adsorption behaviors of the adsorbent were studied for their adsorption capacity, kinetics, thermodynamics and stability. The optimal adsorbent (HPD450/PEI-50) exhibited an excellent adsorption capacity of 4.44 mmol g−1 for pure CO2 and 3.62 mmol g−1 for 15 vol% CO2. Moreover, HPD450/PEI-50 retained an average capacity of 3.58 mmol g−1 under flue gas for 90 consecutive adsorption cycles. The adsorption/desorption process of CO2 on HPD450/PEI-50 was investigated using in situ FTIR. The capture of carbon dioxide in the simulated flue gas stream also demonstrated that moisture had a promoting effect on CO2 adsorption. This design of the high-performance HPD450/PEI-50 with a fantastic CO2 capacity could provide an up-and-coming candidate for CO2 capture from flue gas. [ABSTRACT FROM AUTHOR]

The fine-tuning of metal-based molecular building blocks in Zn-MOF-74 through post-synthetic cation exchange with Ca2+ significantly enhances its basicity and corresponding catalytic performance. The resulting material, exemplified by Ca/Zn-MOF-74, is shown through Knoevenagel condensation to give an improved product yield over the parent Zn-MOF-74 and Ni/Zn-MOF-74. [ABSTRACT FROM AUTHOR]

The simultaneous shaping and confinement of Cu-based MOP in alginate-SiO2 spheres significantly enhance the mechanical strength and leaching resistance of Cu-MOP. The resulting MOP-alginate-SiO2 is shown through chemical fixation of CO2 to exhibit improved product yield over the parent Cu-MOP and Cu-alginate-SiO2.

The fine-tuning of metal-based molecular building blocks in Zn-MOF-74 through post-synthetic cation exchange with Ca2+ significantly enhances its basicity and corresponding catalytic performance. The resulting material, exemplified by Ca/Zn-MOF-74, is shown through Knoevenagel condensation to give an improved product yield over the parent Zn-MOF-74 and Ni/Zn-MOF-74.

Catalytic oxidation can efficiently eliminate nitrogen-containing volatile organic compounds (NVOCs) and suppress the generation of toxic NO x in order to avoid secondary pollution. In this study, mesoporous SiO 2 -confined LaMnO 3 perovskite nanoparticles with high dispersion were successfully prepared by a citric acid-assisted deposition method (LMO/SiO 2 -SD) and tested for the oxidation of n -butylamine. The method utilized the synergistic effect of abundant active hydroxyl groups existing on the SiO 2 gel surface and citric acid, rendering the metal ions more uniformly scattered on the SiO 2 surface. Strikingly, the LMO/SiO 2 -SD sample exhibited the optimum catalytic performance ( T 90 at 246 °C) and the highest N 2 selectivity, which was mainly ascribed to its abundant surface acid sites, superior low-temperature reducibility and higher ratio of surface Mn 4+ species. The apparent activation energy ( E a ) for n -butylamine oxidation over LMO/SiO 2 -SD sample was 29.0 kJ mol -1 . Furthermore, the reaction mechanism of n -butylamine oxidation was investigated by in situ FITR and a reasonable reaction route for n -butylamine oxidation over the LMO/SiO 2 -SD sample was proposed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We reported the morphology-directed synthesis of Co(3)O(4) nanotubes via interfacial reaction of NaOH with pre-fabricated CoC(2)O(4)·2H(2)O nanorods based on modified Kirkendall effect. The as-obtained Co(3)O(4) nanotubes showed excellent activity and durability in catalytic combustion of CH(4)., (This journal is © The Royal Society of Chemistry 2012)