Endre søk
Begrens søket
1 - 14 of 14
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abdelhamid, Hani Nasser
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    El-Zhory, Ahmed M.
    Haoquan, Zheng
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules2017Inngår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, nr 15, s. 9139-9146Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic imidazolate framework ZIF-8 nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim). Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300–2500 m2/g), and large pore volumes (0.5–1.0 cm3/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3–27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIF (dye@ZIF-67).

  • 2. Carmona, Francisco J.
    et al.
    Maldonado, Carmen R.
    Ikemura, Shuya
    Romao, Carlos C.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Xu, Hongyi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Kitagawa, Susumu
    Furukawa, Shuhei
    Barea, Elisa
    Coordination Modulation Method To Prepare New Metal-Organic Framework-Based CO-Releasing Materials2018Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 37, s. 31158-31167Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aluminum-based metal organic frameworks (MOFs), [Al(OH)(SDC)](n), (H2SDC: 4,4'-stilbenedicarboxylic acid), also known as CYCU-3, were prepared by means of the coordination modulation method to produce materials with different crystal size and morphology. In particular, we screened several reagent concentrations (20-60 mM) and modulator/ligand ratios (0-50), leading to 20 CYCU x_y materials (x: reagent concentration, y = modulator/ligand ratio) with different particle size and morphology. Noteworthy, the use of high modulator/ligand ratio gives rise to a new phase of CYCU-3 (CYCU-3' x_50 series), which was structurally analyzed. Afterward, to test the potential of these materials as CO-prodrug carriers, we selected three of them to adsorb the photo- and bioactive CO-releasing molecule (CORM) ALF794 [Mo(CNCMe2CO2H)(3)(CO)(3)] (CNCMe2CO2H = 2-isocyano-2-methyl propionic acid): (i) CYCU-3 20_0, particles in the nanometric range; (ii) CYCU-3 50_5, bar-type particles with heterogeneous size, and (iii) CYCU-3' 50_50, a new phase analogous to pristine CYCU-3. The corresponding hybrid materials were fully characterized, revealing that CYCU-3 20_0 with the smallest particle size was not stable under the drug loading conditions. Regarding the other two materials, similar ALF794 loadings were found (0.20 and 0.19 CORM/MOF molar ratios for ALF794@CYCU-3 50_5 and ALF794@CYCU-3' 50_50, respectively). In addition, these hybrid systems behave as CO-releasing materials (CORMAs), retaining the photoactive properties of the pristine CORM in both phosphate saline solution and solid state. Finally, the metal leaching studies in solution confirmed that ALF794@CYCU-3' 50_50 shows a good retention capacity toward the potentially toxic molybdenum fragments (7S% of retention after 72 h), which is the lowest value reported for a MOF-based CORMA to date.

  • 3. Feng, Dawei
    et al.
    Lei, Ting
    Lukatskaya, Maria R.
    Park, Jihye
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Lee, Minah
    Shaw, Leo
    Chen, Shucheng
    Yakovenko, Andrey A.
    Kulkarni, Ambarish
    Xiao, Jianping
    Fredrickson, Kurt
    Tok, Jeffrey B.
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Cui, Yi
    Bao, Zhenan
    Robust and conductive two-dimensional metal-organic frameworks with exceptionally high volumetric and areal capacitance2018Inngår i: Nature Energy, ISSN 2058-7546, Vol. 3, nr 1, s. 30-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For miniaturized capacitive energy storage, volumetric and areal capacitances are more important metrics than gravimetric ones because of the constraints imposed by device volume and chip area. Typically used in commercial supercapacitors, porous carbons, although they provide a stable and reliable performance, lack volumetric performance because of their inherently low density and moderate capacitances. Here we report a high-performing electrode based on conductive hexaaminobenzene (HAB)-derived two-dimensional metal-organic frameworks (MOFs). In addition to possessing a high packing density and hierarchical porous structure, these MOFs also exhibit excellent chemical stability in both acidic and basic aqueous solutions, which is in sharp contrast to conventional MOFs. Submillimetre-thick pellets of HAB MOFs showed high volumetric capacitances up to 760 F cm(-3) and high areal capacitances over 20 F cm(-2). Furthermore, the HAB MOF electrodes exhibited highly reversible redox behaviours and good cycling stability with a capacitance retention of 90% after 12,000 cycles. These promising results demonstrate the potential of using redox-active conductive MOFs in energy-storage applications.

  • 4. Liang, Zuozhong
    et al.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Yuan, Haitao
    Yang, Zhiyuan
    Zhang, Chaochao
    Xu, Yang
    Zhang, Wei
    Zheng, Haoquan
    Cao, Rui
    Quasi-single-crystalline CoO hexagrams with abundant defects for highly efficient electrocatalytic water oxidation2018Inngår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 9, nr 34, s. 6961-6968Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Defects and structural long-range ordering have been recognized as two crucial characters for advanced electrocatalysts. However, these two features have rarely been achieved together. Herein, we report the preparation of single-crystalline CoO hexagrams and demonstrate their exceptional electrocatalytic properties for water oxidation. The quasi-single-crystalline CoO hexagrams, prepared at the critical phase transition point of -Co(OH)(2)/Co(OH)F hexagrams, possess both abundant oxygen vacancies as defects and structural long-range ordering. The matching between the b-axis of Co(OH)F crystals and the a-axis of -Co(OH)(2) crystals is critical for the formation of the CoO hexagram single crystals. The quasi-single-crystalline CoO hexagrams with abundant defects are highly efficient for water oxidation by delivering a 10 mA cm(-2) current density at a low overpotential of 269 mV in a 1 M KOH aqueous solution.

  • 5. Liang, Zuozhong
    et al.
    Yang, Zhiyuan
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Qi, Jing
    Chen, Mingxing
    Zhang, Wei
    Zheng, Haoquan
    Sun, Junliang
    Cao, Rui
    Novel insight into the epitaxial growth mechanism of six-fold symmetrical beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams and their water oxidation activity2018Inngår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 271, s. 526-536Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The six-fold symmetry widely presents in both natural and artificial architectures. Understanding the growth mechanism of six-fold symmetrical materials is of fundamental interest and significance. Herein, we report the formation process of beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams with a six-fold symmetrical arrangement. Our results demonstrate that hexagonal beta-Co(OH)(2) plates are first formed under the reaction condition. These hexagonal plates then act as templates for the growth of Co(OH)F nanorods. The intermediate material is therefore composed of plate-like beta-Co(OH)(2) hexagonal cores appended with six rod-like Co(OH)F branches, giving the beta-Co(OH)(2)/Co(OH)F hybrid. After prolonged reaction, the beta-Co(OH)(2) hexagons can be completely converted, leading to authentic six-branched Co(OH)F nanorods as the final product. Consequently, for both intermediate and final materials, the Co(OH)F nanorods are arranged with a six-fold symmetry. Importantly, these Co(OH)F nanorods grow along beta-Co(OH)(2) hexagon edges as lateral branches instead of perpendicular to hexagons. This uncommon epitaxial growth mechanism is considered to be a result of the matching between the b-axis of Co(OH)F crystals and the a-axis of beta-Co(OH)(2) crystals, which is beneficial for the electrocatalysis. The beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams show enhanced water oxidation activity compared to the pure beta-Co(OH)(2) and Co(OH)F.

  • 6. Mohideen, M. Infas H.
    et al.
    Lei, Chen
    Tuček, Jiří
    Malina, Ondřej
    Brivio, Federico
    Kasneryk, Valeryia
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Mazur, Michal
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Nachtigall, Petr
    Čejka, Jiří
    Morris, Russell E.
    Magneto-structural correlations of novel kagome-type metal organic frameworks2019Inngår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 7, nr 22, s. 6692-6697Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here, we report the in situ formation of two novel metal organic frameworks based on copper and cobalt using tetrazole-5-carboxylate ethyl ester as the ligand synthesized by a hydrothermal route. Both MOFs show isostructural three-dimensional networks with kagome ' tilling topology and show high chemical stability. Despite the iso-structural nature, both systems show distinct magnetic features. For the Cu-based kag-MOF system, the co-existence of energetically competing ferromagnetic and antiferromagnetic interactions resulted in the establishment of a long-range ferromagnetic order sustainable up to 52 K. On the contrary, dominant antiferromagnetic interactions identified in the Co-based MOF material were responsible for an antiferromagnetic order evolving below 7 K. Importantly, chemically different metallic ions gave rise to distinct magnetic ordering with different strength and temperature-sustainability. No dynamic magnetic phenomena were observed, implying that the concentration of the metal ions within the structure exceeded the percolation limit favoring the formation of the long-range magnetic order in the studied systems. Both designed kagome ' -type MOFs were thus found to show a coexistence of high frustration and long range magnetic ordering with limited orbital quenching, resulting from the choice of the ligands and crystal arrangement. Thus, the results demonstrated the potentiality to effectively control and alter the magnetic features within the particular kagome ' -type MOF lattice due to the chemical nature and structural incorporation of individual metal ions. The presented approach offers a promising strategy to further fine tune the physical characteristics of the MOF-based systems equipping them with more competitive potential and extending their application portfolio to other fields.

  • 7. Park, Jihye
    et al.
    Hinckley, Allison C.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Feng, Dawei
    Yakoyenko, Andrey A.
    Lee, Minah
    Chen, Shucheng
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Bao, Zhenan
    Synthetic Routes for a 2D Semiconductive Copper Hexahydroxybenzene Metal-Organic Framework2018Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 140, nr 44, s. 14533-14537Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Conductive metal-organic frameworks (c-MOFs) have shown outstanding performance in energy storage and electrocatalysis. Varying the bridging metal species and the coordinating atom are versatile approaches to tune their intrinsic electronic properties in c-MOFs. Herein we report the first synthesis of the oxygen analog of M-3(C6X6)(2) (X = NH, S) family using Cu(II) and hexahydroxybenzene (HHB), namely Cu-HHB [Cu-3(C6O6)(2)], through a kinetically controlled approach with a competing coordination reagent. We also successfully demonstrate an economical synthetic approach using tetrahydroxyquinone as the starting material. Cu-HHB was found to have a partially eclipsed packing between adjacent 2D layers and a bandgap of approximately 1 eV. The addition of Cu-HHB to the family of synthetically realized M-3(C6X6)(2) c-MOFs will enable greater understanding of the influence of the organic linkers and metals, and further broadens the range of applications for these materials.

  • 8. Park, Jihye
    et al.
    Lee, Minah
    Feng, Dawei
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Hinckley, Allison C.
    Yakoyenko, Andrey
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Cui, Yi
    Bao, Zhenan
    Stabilization of Hexaaminobenzene in a 2D Conductive Metal-Organic Framework for High Power Sodium Storage2018Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 140, nr 32, s. 10315-10323Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Redox-active organic materials have gained growing attention as electrodes of rechargeable batteries. However, their key limitations are the low electronic conductivity and limited chemical and structural stability under redox conditions. Herein, we report a new cobalt-based ;2D conductive metal-organic framework (MOF), Co-HAB, having stable, accessible, dense active sites for high-power energy storage device through conjugative coordination between a redox-active linker, hexaaminobenzene (HAB), and a Co(II) center. Given the exceptional capability of Co-HAB for stabilizing reactive HAB, a reversible three-electron redox reaction per HAB was successfully demonstrated for the first time, thereby presenting a promising new electrode material for sodium-ion storage. Specifically, through synthetic tunability of Co-HAB, the bulk electrical conductivity of 1.57 S cm(-1) was achieved, enabling an extremely high rate capability, delivering 214 mAh g(-1) within 7 min or 152 mAh g(-1) in 45 s. Meanwhile, an almost linear increase of the areal capacity upon increasing active mass loading up to 9.6 mg cm(-2) was obtained, demonstrating 2.6 mAh cm(-2) with a trace amount of conducting agent.

  • 9. Roy, Souvik
    et al.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Bhunia, Asamanjoy
    Castner, Ashleigh
    Gupta, Arvind K.
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Ott, Sascha
    Electrocatalytic Hydrogen Evolution from a Cobaloxime-Based Metal-Organic Framework Thin Film2019Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 141, nr 40, s. 15942-15950Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Molecular hydrogen evolution catalysts (HECs) are synthetically tunable and often exhibit high activity, but they are also hampered by stability concerns and practical limitations associated with their use in the homogeneous phase. Their incorporation as integral linker units in metal-organic frameworks (MOFs) can remedy these shortcomings. Moreover, the extended three-dimensional structure of MOFs gives rise to high catalyst loadings per geometric surface area. Herein, we report a new MOF that exclusively consists of cobaloximes, a widely studied HEC, that act as metallo-linkers between hexanuclear zirconium clusters. When grown on conducting substrates and under applied reductive potential, the cobaloxime linkers promote electron transport through the film as well as function as molecular HECs. The obtained turnover numbers are orders of magnitude higher than those of any other comparable cobaloxime system, and the molecular integrity of the cobaloxime catalysts is maintained for at least 18 h of electrocatalysis. Being one of the very few hydrogen evolving electrocatalytic MOFs based on a redox-active metallo-linker, this work explores uncharted terrain for greater catalyst pathways.

  • 10.
    Wang, Bin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Rhauderwiek, Timo
    Inge, Andrew Kentaro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Xu, Hongyi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Yang, Taimin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Stock, Norbert
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    A Porous Cobalt Tetraphosphonate Metal-Organic Framework: Accurate Structure and Guest Molecule Location Determined by Continuous-Rotation Electron Diffraction2018Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, nr 66, s. 17429-17433Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Single-crystal electron diffraction has shown to be powerful for structure determination of nano- and submicron-sized crystals that are too small to be studied by single-crystal X-ray diffraction. However, it has been very challenging to obtain high quality electron diffraction data from beam sensitive crystals such as metal-organic frameworks (MOFs). It is even more difficult to locate guest species in the pores of MOF crystals. Here, we present synthesis of a novel porous cobalt MOF with 1D channels, [Co-2(Ni-H4TPPP)]center dot 2DABCO center dot 6H(2)O, (denoted Co-CAU-36; DABCO=1,4-diazabicyclo[2.2.2]octane), and its structure determination using continuous rotation electron diffraction (cRED) data. By combining a fast hybrid electron detector with low sample temperature (96 K), high resolution (0.83-1.00 angstrom) cRED data could be obtained from eight Co-CAU-36 crystals. Independent structure determinations were conducted using each of the eight cRED datasets. We show that all atoms in the MOF framework could be located. More importantly, we demonstrate for the first time that organic molecules in the pores, which were previously difficult to find, could be located using the cRED data. A comparison of eight independent structure determinations using different datasets shows that structural models differ only on average by 0.03(2) angstrom for the framework atoms and 0.10(6) and 0.16(12) angstrom for DABCO and water molecules, respectively.

  • 11.
    Yuan, Ning
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). Swedish University of Agricultural Sciences, Sweden.
    Pascanu, Vlad
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Heidenreich, Niclas
    Leubner, Sebastian
    Inge, A. Ken
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Gaar, Jakob
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Stock, Norbert
    Persson, Ingmar
    Martín-Matute, Belén
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Probing the active catalytic species generated from Pd(II)@MIL-101-NH2 in Heck coupling reactions: An operando X-ray absorption spectroscopy studyArtikkel i tidsskrift (Fagfellevurdert)
  • 12.
    Yuan, Ning
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). Swedish University of Agricultural Sciences, Sweden.
    Pascanu, Vlad
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Valiente, Alejandro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Heidenreich, Niclas
    Leubner, Sebastian
    Inge, Andrew Kentaro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Gaar, Jakob
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Stock, Norbert
    Persson, Ingmar
    Martín-Matute, Belén
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study2018Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 140, nr 26, s. 8206-8217Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (H-1 NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.

  • 13. Yuan, Shuai
    et al.
    Qin, Jun-Sheng
    Xu, Hai-Qun
    Su, Jie
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Rossi, Daniel
    Chen, Yuanping
    Zhang, Liangliang
    Lollar, Christina
    Wang, Qi
    Jiang, Hai-Long
    Son, Dong Hee
    Xu, Hongyi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Zhou, Hong-Cai
    [Ti8Zr2O12(COO)(16)] Cluster: An Ideal Inorganic Building Unit for Photoactive Metal-Organic Frameworks2018Inngår i: Acs Central Science, ISSN 2374-7943, Vol. 4, nr 1, s. 105-111Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metal-organic frameworks (MOFs) based on Ti-oxo clusters (Ti-MOFs) represent a naturally self-assembled superlattice of TiO2 nanoparticles separated by designable organic linkers as antenna chromophores, epitomizing a promising platform for solar energy conversion. However, despite the vast, diverse, and well-developed Ti-cluster chemistry, only a scarce number of Ti-MOFs have been documented. The synthetic conditions of most Ti-based clusters are incompatible with those required for MOF crystallization, which has severely limited the development of Ti-MOFs. This challenge has been met herein by the discovery of the [Ti8Zr2O12(COO)(16)] cluster as a nearly ideal building unit for photoactive MOFs. A family of isoreticular photoactive MOFs were assembled, and their orbital alignments were fine-tuned by rational functionalization of organic linkers under computational guidance. These MOFs demonstrate high porosity, excellent chemical stability, tunable photoresponse, and good activity toward photocatalytic hydrogen evolution reactions. The discovery of the [Ti8Zr2O12(COO)(16)] cluster and the facile construction of photoactive MOFs from this cluster shall pave the way for the development of future Ti-MOF-based photocatalysts. GRAPHICS

  • 14.
    Zheng, Haoquan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). Shaanxi University, China.
    Svengren, Henrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Huang, Zhehao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Yang, Zhiyuan
    Zou, Xiaodong
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Johnsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Hollow titania spheres loaded with noble metal nanoparticles for photocatalytic water oxidation2018Inngår i: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 264, s. 147-150Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A synthesis procedure for fabrication of hollow TiO2 spheres of mixed anatase/rutile composition loaded with noble metal nanoparticles (Au, Pt, Pd) is proposed. The materials demonstrated to be functioning photocatalysts for water oxidation. In particular nanoparticles loaded with Pd and Pt showed good catalytic activity in comparison to commercial TiO2 P25.

1 - 14 of 14
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf