Searched for: subject:"Photocatalysis"
(1 - 19 of 19)
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Khodadadian, F. (author)
Photocatalysis involves the absorption of photons by a semiconductor to enhance chemical reactions. Examples of important applications include the degradation of hazardous chemicals, reduction of carbon dioxide to valuable chemicals and (partial) oxidation of hydrocarbons. Despite many successful demonstrations of this technology at lab-scale,...
doctoral thesis 2019
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van Schie, M.M.C.H. (author), Zhang, W. (author), Tieves, F. (author), Choi, Da Som (author), Park, Chan Beum (author), Burek, Bastien O. (author), Bloh, Jonathan Z. (author), Arends, I.W.C.E. (author), Paul, C.E. (author), Alcalde, Miguel (author), Hollmann, F. (author)
Peroxygenases are very interesting catalysts for specific oxyfunctionalization chemistry. Instead of relying on complicated electron transport chains, they rely on simple hydrogen peroxide as the stoichiometric oxidant. Their poor robustness against H<sub>2</sub>O<sub>2</sub> can be addressed via in situ generation of H<sub>2</sub>O<sub>2<...
journal article 2019
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Burek, Bastien O. (author), de Boer, Sabrina R. (author), Tieves, F. (author), Zhang, W. (author), van Schie, M.M.C.H. (author), Bormann, Sebastian (author), Alcalde, Miguel (author), Holtmann, Dirk (author), Hollmann, F. (author)
Photoenzymatic cascades can be used for selective oxygenation of C−H-Bonds under mild conditions circumventing the hydrogen peroxide mediated peroxygenase inactivation via in situ H<sub>2</sub>O<sub>2</sub> generation. Here, we report the “on demand” production of hydrogen peroxide via methanol assisted reduction of molecular oxygen using UV...
journal article 2019
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Willot, S.J. (author), Fernandez Fueyo, E. (author), Tieves, F. (author), Pesic, M. (author), Alcalde, Miguel (author), Arends, I.W.C.E. (author), Park, Chan Beum (author), Hollmann, F. (author)
Peroxygenases require a controlled supply of H<sub>2</sub>O<sub>2</sub> to operate efficiently. Here, we propose a photocatalytic system for the reductive activation of ambient O<sub>2</sub> to produce H<sub>2</sub>O<sub>2</sub> which uses the energy provided by visible light more efficiently based on the combination of wavelength...
journal article 2019
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Elkalliny, A.S.M. (author), Rivandi, Alireza H. (author), Uzun, S. (author), van Ommen, J.R. (author), Nugteren, H.W. (author), Rietveld, L.C. (author), Appel, P.W. (author)
The rate of photocatalytic oxidation of contaminants in drinking water using an immobilized catalyst can be increased by properly designing the catalyst structure. By creating a solar reactor in which meshes coated with TiO<sub>2</sub> were stacked, we demonstrated that degradation of humic acids with four superimposed stainless steel meshes...
journal article 2019
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Fadlallah, M. M. (author), Shibl, M. F. (author), Vlugt, T.J.H. (author), Schwingenschlögl, U. (author)
The large band gap of SrTiO<sub>3</sub> is disadvantageous for photocatalytic applications. We therefore study cation codoping to modify the size of the band gap and extend the absorption to visible light. We identify efficient codoping schemes that guarantee charge compensation to avoid creation of localized states. Using the Heyd-Scuseria...
journal article 2018
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Huijbers, M.M.E. (author), Zhang, W. (author), Tonin, F. (author), Hollmann, F. (author)
The photoenzymatic decarboxylation of fatty acids to alkanes is proposed as an alternative approach for the synthesis of biodiesel. By using a recently discovered photodecarboxylase from Chlorella variabilis NC64A (CvFAP) we demonstrate the irreversible preparation of alkanes from fatty acids and triglycerides. Several fatty acids and their...
journal article 2018
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Zhang, W. (author), Fernandez Fueyo, E. (author), Hollmann, F. (author), Leemans Martin, L. (author), Pesic, M. (author), Wardenga, Rainer (author), Höhne, Matthias (author), Schmidt, S. (author)
In this study, we combined photo-organo redox catalysis and biocatalysis to achieve asymmetric C–H bond functionalization of simple alkane starting materials. The photo-organo catalyst anthraquinone sulfate (SAS) was employed to oxyfunctionalise alkanes to aldehydes and ketones. We coupled this light-driven reaction with asymmetric enzymatic...
journal article 2018
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Zhang, W. (author), Burek, Bastien O. (author), Fernandez Fueyo, E. (author), Alcalde, Miguel (author), Bloh, Jonathan Z. (author), Hollmann, F. (author)
Selective oxyfunctionalizations of inert C−H bonds can be achieved under mild conditions by using peroxygenases. This approach, however, suffers from the poor robustness of these enzymes in the presence of hydrogen peroxide as the stoichiometric oxidant. Herein, we demonstrate that inorganic photocatalysts such as gold–titanium dioxide...
journal article 2017
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Garcia Santaclara, J. (author)
The fascinating chemical and physical properties of MOFs have recently stimulated exploration of their application for photocatalysis. Despite the intense research effort, the efficiencies of most photocatalytic MOFs for solar fuel generation are still very modest. In this introduction we analyse the current status of the field and stress the...
doctoral thesis 2017
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van Driel, B.A. (author), Wezendonk, T.A. (author), van den Berg, K. J. (author), Kooyman, P.J. (author), Gascon, Jorge (author), Dik, J. (author)
Titanium white (TiO<sub>2</sub>) has been widely used as a pigment in the 20th century. However, its most photocatalytic form (anatase) can cause severe degradation of the oil paint in which it is contained. UV light initiates TiO<sub>2</sub>-photocatalyzed processes in the paint film, degrading the oil binder into volatile components...
journal article 2017
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Zhang, W. (author), Gacs, Jenő (author), Arends, I.W.C.E. (author), Hollmann, F. (author)
The aerobic organocatalytic oxidation of alcohols was achieved by using water-soluble sodium anthraquinone sulfonate. Under visible-light activation, this catalyst mediated the aerobic oxidation of alcohols to aldehydes and ketones. The photo-oxyfunctionalization of alkanes was also possible under these conditions.
journal article 2017
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Lee, Sahng Ha (author), Choi, Da Som (author), Pesic, M. (author), Lee, Yang Woo (author), Paul, C.E. (author), Hollmann, F. (author), Park, Chan Beum (author)
Enoate reductases from the family of old yellow enzymes (OYEs) can catalyze stereoselective trans-hydrogenation of activated C=C bonds. Their application is limited by the necessity for a continuous supply of redox equivalents such as nicotinamide cofactors [NAD(P)H]. Visible light-driven activation of OYEs through NAD(P)H-free, direct...
journal article 2017
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Nasalevich, M.A. (author)
The research strategy followed in this work was inspired by natural photosynthesis that, for simplicity, can be divided into three principal steps: (i) efficient light absorption at wavelengths abundant in the solar light; (ii) long-lived charge separation achieved by funnelling of the photogenerated electrons away from the light-absorbing...
doctoral thesis 2016
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Ni, Y. (author), Hollmann, F. (author)
Oxidoreductases are promising catalysts for organic synthesis. To sustain their catalytic cycles they require efficient supply with redox equivalents. Today classical biomimetic approaches utilizing natural electron supply chains prevail but artificial regeneration approaches bear the promise of simpler and more robust reaction schemes....
book chapter 2016
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Churakova, E. (author)
Biocatalytic oxyfunctionalizations, especially of non - activated hydrocarbons, attract considerable attention for synthetic organic chemistry thanks to their high chemo-, regio-, and stereoselectivity, which difficult to achieve by chemical means. Many enzymatic oxyfunctionalizations have been described. However, there are many hurdles towards...
doctoral thesis 2014
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Wu, Q. (author)
Conventional TiO2 based photocatalysts oxidize NOx to nitrates which do not automatically desorb and have to be washed away from the catalyst surface. To avoid this, the research described in this thesis aims to design new photocatalysts that can photo-reduce NO into N2 and O2. Previous efforts in the literature have shown that catalysts...
doctoral thesis 2012
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Carneiro, J.T. (author), Yang, C.C. (author), Moma, J.A. (author), Moulijn, J.A. (author), Mul, G. (author)
Gold deposition on Hombikat UV100 was found to negatively affect the activity of this Anatase catalyst in selective photo-oxidation of cyclohexane. By ammonia TPD and DRIFT spectroscopy it was determined that the Au deposition procedure leads to a significant decrease in OH-group density (mol m?2 BET) on Hombikat, suggesting that the amount of...
journal article 2009
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Saad, M.S.Hamdy M. (author)
The new mesoporous material; TUD-1 is chosen of which the synthesis, characterization, and functionalization for (photo)-catalytic performance are extensively investigated in this study. The synthesis of the new catalytic materials M TUD-1 (M = Ti, V, Cr, Mo, Fe, Co and Cu) is carried out through an easy one-pot synthesis procedure, mainly...
doctoral thesis 2005
Searched for: subject:"Photocatalysis"
(1 - 19 of 19)