340 research outputs found

    In-situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes

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    Acknowledgments This work was supported by Engineering and Physical Sciences Research Council (EPSRC) Grant EP/I00372X/1. The EPR spectrometer was purchased under EPSRC Grant EP/F032560/1. We thank Andrew Mills for use of the spectroradiometric measurement system.Peer reviewedPublisher PD

    Room temperature methoxylation in zeolite H-ZSM-5 : an operando DRIFTS/mass spectrometric study

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    The UK Catalysis Hub is thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC (grants EP/I038748/1, EP/I019693/1, EP/ K014706/1, EP/K014668/1, EP/K014854/1, EP/K014714/1 and EP/ M013219/1). Via our membership of the UK’s HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202), this work used the ARCHER UK National Supercomputing Service (www.archer.ac.uk). Johnson Matthey plc is thanked for the provision of the ZSM5. Dr A. J. O’Malley and Dr S. F. Parker are thanked for fruitful discussion.Peer reviewedPublisher PD

    Studies of propene conversion over H-ZSM-5 demonstrate the importance of propene as an intermediate in methanol-to-hydrocarbons chemistry

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    Funding Information: Johnson Matthey plc. is thanked for supplying the ZSM-5 zeolite and for financial support through the provision of industrial CASE studentships in partnership with the EPSRC (APH (EP/P510506/1), AZ (EP/N509176/1)). Experiments at the ISIS Neutron and Muon Source were made possible by a beam time allocation from the Science and Technologies Facilities Council. 53 The resources and support provided by the UK Catalysis Hubviamembership of the UK Catalysis Hub consortium and funded by EPSRC grants EP/R026815/1 and EP/R026939/1 are gratefully acknowledged. This research has been performed with the use of facilities and equipment at the Research Complex at Harwell; the authors are grateful to the Research Complex for this access and support.Peer reviewedPublisher PD

    The Methyl Torsion in Unsaturated Compounds

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    The STFC Rutherford Appleton Laboratory is thanked for funding and access to neutron beam facilities. Computing resources (time on the SCARF compute cluster for the CASTEP calculations) was provided by STFC’s e-Science facility. Dr John Tomkinson (ISIS) is thanked for generously providing the INS spectra of the toluene isotopomers. A.Z. and A.P.H. would like to thank Johnson Matthey plc. For financial support through the provision of industrial CASE studentships in partnership with the EPSRC. The UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC grant: EP/R026939/1, EP/R026815/1, EP/R026645/1, EP/R027129/1 or EP/M013219/1(biocatalysis).Peer reviewedPublisher PD

    Food Habits of Introduced Rodents in High-Elevation Shrubland of Haleakala National Park, Maui, Hawai'i

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    Mus musculus and Rattus rattus are ubiquitous consumers in the high-elevation shrubland of Haleakala National Park. Food habits of these two rodent species were determined from stomach samples obtained by snap-trapping along transects located at four different elevations during November 1984 and February, May, and August 1985. Mus musculus fed primarily on fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves, and arthropods. Arthropods, many of which are endemic, were taken frequently by Mus musculus throughout the year at the highest elevation where plant food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera, and Homoptera were the main arthropod taxa taken. These rodents, particularly Mus musculus, exert strong predation pressure on populations of arthropod species, including locally endemic species on upper Haleakala Volcano

    Ultrafast 2D-IR spectroscopy of intensely optically scattering pelleted solid catalysts

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    ACKNOWLEDGMENTS This work was supported by a UKRI Future Leaders Fellowship grant (Grant No. MR/S015574/1), STFC-UKRI program access to CLF-ULTRA (Grant No. LSF1828), direct access to CLF-ULTRA (Grant Nos. Apps 17330043 and 19130012), and a group residency in the Research Complex at Harwell (RCaH). The authors are grateful to Kathryn Welsby, Ivalina Minova, and Santhosh Matam for support early in the project with samples and the Linkam cell. Mr. John Still of the School of Geosciences, University of Aberdeen is thanked for the SEM images, and Kieran Farrell/Martin Zanni is thanked for the discussion about the polarizations of the beams creating the thermal transientsPeer reviewedPublisher PD

    Cofactor NAD(P)H regeneration:how selective are the reactions?

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    The regeneration of NAD(P)H can be achieved via catalysis, but the unequivocal determination of the species involved has not yet been fully realized. The current analytical methods of reactant/product analysis based on UV-vis spectroscopy, enzymatic assays, NMR spectroscopy, and HPLC are critically examined here with suggestions for future development

    New Spectroscopic Insight into the Deactivation of a ZSM-5 Methanol-to-Hydrocarbons Catalyst

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    Funding Information: Johnson Matthey plc. is thanked for supplying the ZSM‐5 zeolite and for financial support through the provision of industrial CASE studentships in partnership with the EPSRC (APH (EP/P510506/1), AZ (EP/N509176/1)). Experiments at the ISIS Neutron and Muon Source were made possible by a beam time allocation from the Science and Technologies Facilities Council. The resources and support provided by the UK Catalysis Hub membership of the UK Catalysis Hub consortium and funded by EPSRC grants EP/R026815/1 and EP/R026939/1 are gratefully acknowledged. This research has been performed with the use of facilities and equipment at the Research Complex at Harwell; the authors are grateful to the Research Complex for this access and support. Dr Andrea Sauerwein and Dr Jonathan Bradley (Johnson Matthey) are thanked for their help in acquiring the Si and Al NMR spectra using the Bruker Avance Neo spectrometer.Peer reviewedPublisher PD

    Onset of propene oligomerization reactivity in ZSM-5 studied by inelastic neutron scattering spectroscopy

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    The techniques of quasi-elastic and inelastic neutron scattering (QENS and INS) are applied to investigate the oligomerization of propene over a ZSM-5 zeolite. Investigations are performed at low temperatures, allowing identification of the onset of the oligomerization reaction and observation of the low-energy spectral changes due to intermediate formation that are difficult to observe by optical methods. Oligomerization proceeds via formation of a hydrogen-bonded precursor by an interaction of the propene with an internal acid site followed by protonation and chain growth with protonation being the rate-limiting step. The use of quasi-elastic neutron scattering to observe changes in system mobility with temperature via the elastic window scan technique allows identification of the active temperature range where catalyst activity commences and permits targeting of the more time-consuming INS investigations to conditions of interest. From examination of the product’s spectrum, the structure of the resulting oligomer is deduced to be primarily linear
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