Cu(<scp>ii</scp>)/Cu(0)@UiO-66-NH<sub>2</sub>: base metal@MOFs as heterogeneous catalysts for olefin oxidation and reduction

Wang, Jiancheng; Hu, Yuhong; Chen, Gong-Jun; Dong, Yu‐Bin

doi:10.1039/c6cc06076e

Cited by 44 publications

(28 citation statements)

References 32 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[102] HRTEM images revealed the existence of spherical shaped Cu particles which are uniformly distributed with an average size of 4-6 nm. In this aspect, Cu (OAc) 2 was adsorbed on UiO-66-NH 2 nanocrystals in ethanol at room temperature to obtain Cu(II)@UiO-66-NH 2 which upon reduction with NaBH 4 resulted in Cu@UiO-66-NH 2 .…”

Section: Cu Npsmentioning

confidence: 99%

“…The catalytic activity of Cu@UiO-66-NH 2 was examined in the reduction of styrene using hydrazine as reducing agent. [102] HRTEM images revealed the existence of spherical shaped Cu particles which are uniformly distributed with an average size of 4-6 nm. Cu@UiO-66-NH 2 catalyst completely converted styrene to ethylbenzene using hydrazine hydrate at room temperature in ethanol with a TOF value of 100 h À 1 .…”

Section: Cu Npsmentioning

confidence: 99%

See 1 more Smart Citation

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

et al. 2019

View full text Add to dashboard Cite

frameworks (MOFs) are currently attracting considerable attention as heterogeneous catalysts at moderate temperatures, mainly for liquid-phase reactions. Since structural stability is one of the major concerns for the use of MOFs in catalysis, particularly considering that frequently some of the reported MOF materials are very unstable, the interest in this area has been focused on those MOFs exhibiting the highest structural robustness, UiO-66 being among the most widely used. Two introductory sections deal with the synthesis, structure and main properties of UiO-66, including its remarkable thermal (up to 350°C) and chemical (aqueous solution in a wide pH range) stability. The main body of the review summarizes those examples of using UiO-66 in catalysis grouped according to the nature of the active sites, starting with the use of UiO-66 as Lewis acids. In this section, emphasis has been made in the recent strategies to create structural defects in a controlled way that generate Lewis acidity. Other sections cover examples illustrating substituted terephthalate as active sites and the evidence that there is a synergy between acid and basic sites in close proximity that make some of these UiO-66 with substituents at the linker to act as dual acid-base catalysts. Other sections are focused on the use of UiO-66 as hosts of metal nanoparticles, metal oxides and other host, remarking the influence that the nature of UiO-66 and the possible presence of substituents in the framework play on the activity of the incorporated guest. The last section summarizes the current state of the art in the use of UiO-66 in catalysis and provides our views on future developments regarding the application of UiO-66 in industrial processes.

show abstract

Section: Cu Npsmentioning

confidence: 99%

Section: Cu Npsmentioning

confidence: 99%

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

et al. 2019

View full text Add to dashboard Cite

show abstract

“…A number of papers concerning catalytic performance of the UiO-66 modified in Zr nodes or the BDC linker, or decorated with metals, was published. For example, the Cu(II)-and Cu 0 -loaded UiO-66-NH 2 hybrids were found to be highly efficient heterogeneous catalysts for oxidation of cyclohexene and hydrogenation of styrene under mild conditions [28].…”

Section: Introductionmentioning

confidence: 99%

CO2 Hydrogenation to Methanol over Ce and Zr Containing UiO-66 and Cu/UiO-66

et al. 2019

View full text Add to dashboard Cite

Direct hydrogenation of CO 2 to methanol is an interesting method to recycle CO 2 emitted e.g., during combustion of fossil fuels. However, it is a challenging process because both the selectivity to methanol and its production are low. The metal-organic frameworks are relatively new class of materials with a potential to be used as catalysts or catalysts supports, also in the reaction of MeOH production. Among many interesting structures, the UiO-66 draws significant attention owing to its chemical and thermal stability, developed surface area, and the possibility of tuning its properties e.g., by exchanging the zirconium in the nodes to other metal cations. In this work we discuss-for the first time-the performance of Cu supported on UiO-66(Ce/Zr) in CO 2 hydrogenation to MeOH. We show the impact of the composition of UiO-66-based catalysts, and the character of Cu-Zr and Cu-Ce interactions on MeOH production and MeOH selectivity during test carried out for 25 h at T = 200 • C and p = 1.8 MPa. Significant increase of selectivity to MeOH was noticed after exchanging half of Zr 4+ cations with Ce 4+ ; however, no change in MeOH production occurred. It was found that the Cu-Ce coexistence in the UiO-66-based catalytic system reduced the selectivity to MeOH when compared to Cu/UiO-66(Zr), which was ascribed to lower concentration of Cu 0 active sites in Cu/UiO-66(Ce/Zr), and this was caused by oxygen spill-over between Cu 0 and Ce 4+ , and thus, the oxidation of the former. The impact of reaction conditions on the structure stability of tested catalyst was also determined.Catalysts 2020, 10, 39 2 of 17Synthesis of MeOH is an exothermic reaction that leads to the reduction of the number of molecules; therefore, according to the Le Chatelier's principle, the increase of the pressure and decrease of temperature will favor product formation. However, CO 2 is a chemically inert molecule and its activation requires some increase in reaction temperature. The process is usually carried out over Cu/ZnO/Al 2 O 3 catalyst at temperatures between 230 and 280 • C and at elevated pressure of 50-120 bar [1][2][3][4][5]. The active site for MeOH production from CO 2 consists of Cu steps decorated with Zn atoms. Copper, when alone, interacts with CO 2 poorly; hence, the presence of Zn is necessary to enhance its adsorption and speed up its conversion to methanol [6].MeOH production via CO 2 hydrogenation is a challenging process since the selectivity of the reaction is low and a number of unnecessary and undesired by-products is formed. At higher temperatures the CO formation is favored, so the RWGS reaction (Equation (3)) can occur during MeOH synthesis. That reaction consumes hydrogen and lowers alcohol production. Besides, both the MeOH synthesis (Equation (2)) and RWGS reaction (Equation (3)) produce H 2 O that leads to catalyst deactivation by inhibiting the active metal [7].Direct hydrogenation of CO 2 to obtain methanol is an interesting method to recycle the CO 2 produced, e.g., during combustion of fossil fuels; therefore,...

show abstract

“…The metal‐loaded (generally based on noble metals) MOF‐based heterogeneous catalytic systems appear to exhibit advantages over traditional catalysts of shorter duration and good recyclability. Many metal@MOF systems have been explored and found to exhibit good catalytic behavior towards olefin hydrogenation, aerobic oxidation of alcohol, C−C coupling, and so forth. Among these, silver‐loaded MOFs are known to exhibit good catalytic activity…”

Section: Introductionmentioning

confidence: 99%

Encapsulation of Silver Nanoparticles in an Amine‐Functionalized Porphyrin Metal–Organic Framework and Its Use as a Heterogeneous Catalyst for CO₂ Fixation under Atmospheric Pressure

Dutta

Jana

Singh

et al. 2018

Chemistry An Asian Journal

View full text Add to dashboard Cite

A new porphyrin-based compound, [Zn (C H N )(C H N O ) (DEF) ](DEF) (1; DEF=N,N-diethylformamide), has been synthesized by employing 5,10,15,20-tetrakis(4-pyridyl)porphyrin, 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene, and Zn salt at 100 °C under solvothermal conditions. The structure, as determined by single-crystal XRD studies, is three-dimensional with threefold interpenetration. The usefulness of free -NH groups in the ligand was exploited for anchoring silver nanoparticles through a simple solution-based route. The silver-loaded sample, Ag@1, was characterized by powder XRD, energy-dispersive X-ray spectroscopy, high-resolution TEM, SEM, X-ray photoelectron spectroscopy, and inductively coupled plasma MS analysis, which clearly indicated that silver nanoparticles with a size of 3.83 nm were uniformly distributed within the metal-organic framework (MOF). The Ag@1 sample was evaluated for possible catalytic activity for the carboxylation of a terminal alkyne by employing CO under atmospheric pressure; this gave excellent results. The Ag@1 catalyst was found to be robust, active, and recyclable. The present studies suggest that porphyrin MOFs not only exhibit interesting structures, but also show good heterogeneous catalytic activity towards the fixation of CO .

show abstract

Cu(ii)/Cu(0)@UiO-66-NH₂: base metal@MOFs as heterogeneous catalysts for olefin oxidation and reduction

Cited by 44 publications

References 32 publications

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

CO2 Hydrogenation to Methanol over Ce and Zr Containing UiO-66 and Cu/UiO-66

Encapsulation of Silver Nanoparticles in an Amine‐Functionalized Porphyrin Metal–Organic Framework and Its Use as a Heterogeneous Catalyst for CO₂ Fixation under Atmospheric Pressure

Contact Info

Product

Resources

About

Cu(ii)/Cu(0)@UiO-66-NH2: base metal@MOFs as heterogeneous catalysts for olefin oxidation and reduction

Cited by 44 publications

References 32 publications

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

CO2 Hydrogenation to Methanol over Ce and Zr Containing UiO-66 and Cu/UiO-66

Encapsulation of Silver Nanoparticles in an Amine‐Functionalized Porphyrin Metal–Organic Framework and Its Use as a Heterogeneous Catalyst for CO2 Fixation under Atmospheric Pressure

Contact Info

Product

Resources

About

Cu(ii)/Cu(0)@UiO-66-NH₂: base metal@MOFs as heterogeneous catalysts for olefin oxidation and reduction

Encapsulation of Silver Nanoparticles in an Amine‐Functionalized Porphyrin Metal–Organic Framework and Its Use as a Heterogeneous Catalyst for CO₂ Fixation under Atmospheric Pressure