Elucidating the mechanism of the UiO-66-catalyzed sulfide oxidation: activity and selectivity enhancements through changes in the node coordination environment and solvent

Limvorapitux, Rungmai; Chen, Haoyuan; Mendonca, Matthew L.; Liu, Mengtan; Snurr, Randall Q.; Nguyen, SonBinh T.

doi:10.1039/c8cy01139g

Cited by 41 publications

(48 citation statements)

References 66 publications

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“…Finally, we tried to analyze a possible role of defects in the Zr‐MOF structures in the H 2 O 2 ‐based catalytic oxidations. Previously, two groups concluded that defects play a significant role in the thioether oxidation over UiO‐66 [6c, 7b] . TGA measurements showed that the concentration of defects corresponding to the total amount of terminal Zr(OH/H 2 O) groups decreased in the order Zr‐abtc > MIP‐200 > UiO‐67 > UiO‐66 (Table S2, Figures S8–S12 in the Supporting Information).…”

Section: Resultsmentioning

confidence: 94%

“…Zr‐MOFs constructed from the highly robust Zr 6 O n (OH) m clusters and various carboxylate linkers are one of the most attractive classes of MOFs owing to their outstanding thermal, hydrothermal, chemical, and mechanical stability as well as a tunable amount of defects [5] . In particular, the most studied representative of Zr‐MOFs, Zr IV terephthalate UiO‐66, has been employed as a leaching‐tolerant and recyclable catalyst for a range of H 2 O 2 ‐based oxidative transformations, [6, 7] the majority of which were oxidations of S compounds [6a–c, 7b] …”

Section: Introductionmentioning

confidence: 99%

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Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂

Maksimchuk

Ivanchikova

Cho

et al. 2021

Chemistry A European J

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The catalytic performance of Zr‐abtc and MIP‐200 metal–organic frameworks consisting of 8‐connected Zr6 clusters and tetratopic linkers was investigated in H2O2‐based selective oxidations and compared with that of 12‐coordinated UiO‐66 and UiO‐67. Zr‐abtc demonstrated advantages in both substrate conversion and product selectivity for epoxidation of electron‐deficient C=C bonds in α,β‐unsaturated ketones. The significant predominance of 1,2‐epoxide in carvone epoxidation, coupled with high sulfone selectivity in thioether oxidation, points to a nucleophilic oxidation mechanism over Zr‐abtc. The superior catalytic performance in the epoxidation of unsaturated ketones correlates with a larger amount of weak basic sites in Zr‐abtc. Electrophilic activation of H2O2 can also be realized, as evidenced by the high activity of Zr‐abtc in epoxidation of the electron‐rich C=C bond in caryophyllene. XRD and FTIR studies confirmed the retention of the Zr‐abtc structure after the catalysis. The low activity of MIP‐200 in H2O2‐based oxidations is most likely related to its specific hydrophilicity, which disfavors adsorption of organic substrates and H2O2.

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Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂

Maksimchuk

Ivanchikova

Cho

et al. 2021

Chemistry A European J

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“…Such “open” sites are much more coordinatively labile than the chelating carboxylate‐capped sites obtained with acid modulators and can become active sites in catalysis. A combined experimental and computational study shows that monocarboxylate‐capped missing‐linker defects on the Zr 6 ‐oxo‐hydroxo node of UiO‐66 MOFs can be converted into unsaturated coordination sites that serve as good catalysts . However, it cannot be neglected that less crystalline materials suffer from both lower chemical and mechanical stability …”

Section: Mof Catalysts For Odsmentioning

confidence: 99%

Metal‐Organic Framework‐Based Catalysts for Oxidative Desulfurization

et al. 2020

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Oxidative desulfurization (ODS) is emerging as the most promising methodology to remove refractive naturally occurring sulfides from fossil fuels. Metal‐organic frameworks (MOFs), a fascinating class of materials, are suitable as catalysts for this process due to the theoretical infinite number of combinations of polynuclear metal clusters and organic linkers. A rational fine‐tuning of the material structure, porosity and chemical functionality have given rise to a considerable number of MOF‐based catalytic active materials. Furthermore, MOFs can act as host, with programmable cavity sizes to accommodate catalytic species, forming novel robust catalytic MOF composite materials. Herein an account of this growing field of heterogeneous catalysis is reported and discussed, aiming to point out future outlooks and perspectives.

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“…The stability of UiO-66 structure explains its wide use in heterogeneous catalysis. It was studied, e.g., in transesterification of triglyceride with methanol [24], sulphide oxidation [25], desulfurization [26], and other reactions [27]. 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.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2019

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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,...

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Elucidating the mechanism of the UiO-66-catalyzed sulfide oxidation: activity and selectivity enhancements through changes in the node coordination environment and solvent

Abstract: “Open” sites on the nodes of UiO-66 are converted to catalytically active Zr-OOH and can coordinate with solvent/products.

Cited by 41 publications

References 66 publications

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂

Metal‐Organic Framework‐Based Catalysts for Oxidative Desulfurization

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

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Elucidating the mechanism of the UiO-66-catalyzed sulfide oxidation: activity and selectivity enhancements through changes in the node coordination environment and solvent

Abstract: “Open” sites on the nodes of UiO-66 are converted to catalytically active Zr-OOH and can coordinate with solvent/products.

Cited by 41 publications

References 66 publications

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H2O2

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H2O2

Metal‐Organic Framework‐Based Catalysts for Oxidative Desulfurization

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

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Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂

Catalytic Performance of Zr‐Based Metal–Organic Frameworks Zr‐abtc and MIP‐200 in Selective Oxidations with H₂O₂