For the first time, metal‐exchange in a magnetic metal–organic framework (MOF) via tandem magnetization and post‐synthetic modification has been developed. The new magnetic mixed‐metal metal–organic ...framework nanocomposite, CoFe2O4/Cu0.63/Zn0.37‐TMU‐17‐NH2 (CoFe2O4/Cu/Zn‐MOF) has been synthesized by immersing the CoFe2O4/Zn‐TMU‐17‐NH2 (CoFe2O4/Zn‐MOF) as a template in DMF solution of Cu (II) salts. CoFe2O4/Cu/Zn‐MOF showed to be a highly reactive and easily recoverable magnetic catalyst for the preparation of tetrazole derivatives via one‐pot three‐component reactions of different aldehydes with hydroxyl amine hydrochloride and sodium azide. Our results (Fourier transform‐infrared, inductively coupled plasma‐optical emission spectroscopy, powder X‐ray diffraction, field emission‐scanning electron microscopy, energy‐dispersive X‐ray spectroscopy‐mapping and vibrating‐sample magnetometer) show successful partial metal‐exchange in which the framework integrity remained intact during the metal‐exchange process.
For the first time, metal‐exchange in a magnetic metal–organic framework (MOF) via tandem magnetization and post‐synthetic modification has been developed.
Display omitted
•Encapsulating Cu2O into MOF (TMU-17-NH2) as a stable composite.•Using this new synthesized MOF composite in iodine capture in both solution and vapor phases.•Complete removal of ...iodine about 90.1% and maximum iodine sorption capacity about 567 mg/g.•First report on the MOF capsulated metal oxide in iodine capture.•the Cu2O/TMU-17-NH2 composite exhibits stronger emission than the pristine TMU-17-NH2.
The efficient capture and storage of radioactive iodine (129I or 131I) formed during the extensive use of nuclear energy is of paramount importance. Therefore, it is a great deal to design new adsorbents for effectively disposing of iodine from nuclear waste. In this work, a new Cu2O/TMU-17-NH2 composite has been prepared by a simple encapsulation of Cu2O nanoparticles (NPs) into the metal organic framework (MOF) TMU-17-NH2 for the first time. The as-synthesized Cu2O/TMU-17-NH2 was fully characterized in details and the iodine sorption/release capability of the Cu2O/TMU-17-NH2 composite has been investigated both in solution and in the vapor phase. According to the FE-SEM images, the Cu2O/TMU-17-NH2 was obtained with same morphology to that of the pristine TMU-17-NH2. The I2 sorption/release experiments were examined by UV–vis spectroscopy. The optimal iodine sorption was obtained by almost complete removal of iodine with a sorption capacity of about 567 mg/g. Detailed experimental evidence demonstrating that the iodine was captured by chemisorption process. Furthermore, photoluminescence (PL) properties of Cu2O/TMU-17-NH2 have also been investigated in which indicate that the Cu2O/TMU-17-NH2 composite exhibits stronger emission than the pristine TMU-17-NH2.
Display omitted
•The NO and CO adsorption behaviors over Si@C24N24 were discussed.•NO can be simply reduced into N2O over Si@C24N24 through the dimer mechanism.•Introducing Si@C24N24 as active ...catalyst for NO reduction in the presence of CO.•Si@C24N24 can be regarded as a pioneering metal-free catalyst for NO reduction.
The potential application of porphyrin‐like porous C24N24 fullerene decorated with a single Si atom (Si@C24N24) as a highly active catalyst for the reduction of NO in the presence of CO is investigated through the dispersion-corrected DFT calculations. The results reveal that NO can be simply reduced into N2O through the dimer mechanism. This reaction also produces Oads species which is attached to the Si atom. Thereafter, the Oads is eliminated by an incoming CO by overcoming small activation energy of 6.68 kcal/mol. These results demonstrate that the novel Si@C24N24 can be regarded as a pioneering metal-free catalyst for NO reduction.
Display omitted
•The adsorption behaviors of O2 and ethylene molecules over the Fe@C24N24 were discussed.•Fe@C24N24 as a highly active catalyst for the epoxidation of ethylene.•A bimolecular ...Langmuir-Hinshelwood (LH) mechanism was proposed for the epoxidation of C2H4 into EtO on Fe@C24N24.
Density functional theory calculations are used to investigate the reaction mechanisms and activation barriers of ethylene (C2H4) epoxidation by molecular oxygen (O2) using Fe-decorated C24N24 porous fullerene. Calculated adsorption energies demonstrate that the decorated Fe atom has a greater propensity to adsorb O2 molecules than C2H4. The results, on the other hand, indicate that ethylene epoxidation by O2 proceed through the Langmuir Hinshelwood (LH) mechanism. The whole ethylene epoxidation reaction is exothermic, with activation energies ranging from 0.36 to 0.68 eV, showing that this process is both thermodynamically and kinetically favorable. The side reaction, i.e., formation of acetaldehyde, is almost impossible over the proposed catalyst due to its large activation energy.
Efficient reduction of nitro compounds into amines is an important industrial transformation. So, it is a great deal to design new catalysts for efficient reduction of the nitro compounds especially ...in water. In this work, a new magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) was synthesized via metal-impregnation-pyrolysis method. The CoFe2O4@Pd/AC was fully characterized by FT-IR, PXRD, FESEM, TEM, VSM, EDX-mapping and BET techniques. The results showed that CoFe2O4@Pd/AC is a highly reactive and easily recoverable magnetic catalyst for the reduction of the nitro compounds by using NaBH4 in water. For instance, aniline was obtained in high yield (99%) after 75 min at 25 ̊C by using just 6 mg of the catalyst. In addition, CoFe2O4@Pd/AC was recovered by a simple magnetic decantation and it exhibits stable activity and remains intact during the catalytic process with no significant loss in activity (8 cycles).
An efficient and highly recoverable magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) has been synthesized to be an excellent chemoselective recoverable catalyst for nitro-containing compound reduction in water. Display omitted
•A new magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) has been synthesized via metal-impregnation-pyrolysis.•Highly reactive and easily recoverable magnetic catalyst for the reduction of the nitro compounds by using NaBH4 in water.•Excellent chemoselectivity in the nitroaryl compounds containing reducible functional groups.•Recoverable by simple magnetic decantation.
Display omitted
•Fe adsorption over B40 fullerene is investigated.•Fe@B40 fullerene proposed as a highly active noble-metal free catalyst for carbon CO oxidation reaction.•The CO oxidation reaction ...over Fe@B40 is controlled by termolecular Eley–Rideal (TER) mechanism.
In the present research, a special boron-based catalyst was introduced for carbon monoxide oxidation using dispersion-corrected DFT calculations. The iron metal is decorated at hexagonal and heptagonal rings of B40 fullerene, which is discovered as the first experimental boron allotrope in cage form. Accordingly, the Fe atom strongly chemisorbs on top of hexagonal and heptagonal rings of this fullerene. However, the adsorption energy for Fe atom above the hexagonal ring is found to be greater than that of over the heptagonal one. Thus, this complex selected as an appropriate catalyst for investigating the CO oxidation process. The conventional Eley–Rideal (ER), Langmuir–Hinshelwood (LH) and termolecular Eley–Rideal (TER) mechanisms were explored in detail. The outcomes have revealed that the acceptable mechanism for CO oxidation over Fe@B40 substrate is TER pathway. The results might be valuable for designing promising active boron-based catalyst for the CO oxidation.
The potential application of a single Fe atom decorated C24N24 fullerene (Fe@C24N24) as a highly active catalyst for the CO oxidation is investigated through the dispersion-corrected DFT ...calculations. Three different CO oxidation reaction pathways, including the Eley-Rideal (ER), the Langmuir-Hinshelwood (LH) and the termolecular Eley-Rideal (TER) are investigated comparably. Our results indicate that the CO oxidation would like to occur via the TER mechanism owing to its small activation energies. The calculated energy barrier for the rate-determining step of the TER pathway is 0.35 eV. The results reveal that Fe@C24N24 can be regarded as an innovative metal-free catalyst for the low temperature oxidation of toxic CO.
Display omitted
•The adsorption behaviors of O2 and CO molecules over the Fe@C24N24 were discussed.•Fe@C24N24 as a highly active catalyst for the oxidation of CO•TER mechanism is the most energetically favorable one for the oxidation of CO over Fe@C24N24.
A new nano scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper(II) salts. The Cu‐MOF serves as recyclable nano‐catalyst for the ...preparation of 5‐substituted 1H‐tetrazoles via 3 + 2 cycloaddition reaction of various nitriles and sodium azide in a green medium (PEG). The post‐synthetic metalated MOF were characterized by FT‐IR spectroscopy, powder X‐ray diffraction (PXRD), atomic absorption spectroscopy (AAS), and energy dispersive X‐ray spectroscopy (EDX) techniques. The morphology and size of the nano‐catalyst were determined by field emission scanning electron microscopy (FE‐SEM).
A new nano‐scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper (II) salts which serves as an efficient catalyst for the preparation of 5‐substituted 1H‐tetrazoles.
Suzuki-Miyaura Cross-Coupling Reaction catalyzed by Cu-MOF-Pd.
Display omitted
•A new bimetallic Cu-MOF-Pd was synthesized through post-synthetic modifications.•Cu-MOF-Pd act as an efficient catalyst ...in Suzuki–Miyaura cross-coupling reaction.•The Cu-MOF-Pd has uniform distribution of active sites and high density of the Pd.
A new Cu/Pd bimetallic Cu-MOF-Pd was synthesized through covalent, dative and inorganic post-synthetic modifications. In order to achieve the Cu-MOF-Pd, Zn-MOF (TMU-17-NH2) was initially selected and fabricated by grafting of salicylaldehyde via Schiff-base formation followed by complex formation with Pd(II). Then, the as-synthesis MOF, Zn-MOF-Pd, was subjected as 3D-template to obtain Cu-MOF-Pd by transmetalation process. The Cu-MOF-Pd was characterized by FT-IR spectroscopy, atomic absorption spectroscopy (AAS), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDS), and EDS mapping techniques. The feasibility of using Cu-MOF-Pd as a highly active recoverable catalyst was confirmed in the Suzuki–Miyaura cross-coupling reaction in a mixed water/ethanol solvent. The results show that this novel nano-composite could serve as an efficient bimetallic heterogeneous catalyst and reuse at least for 5 times without loss in activity.
A new magnetic metal–organic framework nanocomposite (CoFe2O4/TMU‐17‐NH2) was prepared via an embedding approach by synthesis of the metal–organic framework crystals in the presence of magnetic ...cobalt ferrite nanoparticles. We demonstrated that the resulting magnetic nanocomposite can serve as a recyclable nanocatalyst for one‐pot synthesis of bis‐3,4‐dihydropyrimidin‐2(1H)‐one and 3,4‐dihydropyrimidin‐2(1H)‐one derivatives via three‐component reaction of 1,3‐diketone, urea or thiourea and aromatic aldehyde under solvent‐free conditions. CoFe2O4/TMU‐17‐NH2 was characterized using various techniques. The recovery of the nanocomposite was achieved by a simple magnetic decantation and it was reused at least seven times without significant degradation in catalytic activity.
A new magnetic metal‐organic framework nanocomposite (CoFe2O4/TMU‐17‐NH2) was prepared via embedding approach by synthesis of the MOF crystals in the presence of magnetic cobalt ferrite nanoparticles.
