Scholarly Work - Chemistry & Biochemistry
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/8714
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Item Reactive and Scattering Dynamics of Hyperthermal O and O2 from a Carbon Fiber Network(The Journal of Physical Chemistry C, 2018) Poovathingal, Savio J; Qian, Min; Murray, Vanessa J; Minton, Timothy KWe have investigated the scattering and reactive dynamics of a carbon fiber network at high surface temperatures. The experiments were performed with ground state atomic oxygen (O) and molecular oxygen (O2) with surface temperatures ranging from 1023 K to 1823 K. A molecular beam containing neutral O and O2 with a mole ratio of 0.92:0.08 and nominal velocity of 8 km/s was directed at the surface and the translational energy distributions of the scattered products were collected at various scattering angles and surface temperatures with the use of rotatable mass spectrometer detector. The signals from oxygen atoms exhibited impulsive scattering and thermal desorption with the thermal desorption signals increasing with surface temperature while the impulsive scattering component remained relatively constant. The O2 signals contained impulsive scattering and thermal desorption channels which were invariant to surface temperature. The dominant reactive product was CO, and CO2 was a minor product of reaction. The impulsive scattering signals were absent in CO and CO2 and both these products contained strong thermal desorption signals. The flux of CO increased with temperature but exhibited non-Arrhenius behavior where it reached a plateau at the highest temperature. Thermal CO products were observed to exit the sample promptly or after relatively long residence times and two populations of CO with long residence times were distinguished. Signatures of thermal processes occurring over long residence times were also observed for O. Hysteresis was observed in the thermal flux of O and CO with opposing trends for the two species. This work follows a similar study in our laboratory where the material in focus was vitreous carbon and the similarities and differences between the reactive dynamics of the two carbon surfaces are explored in this article.Item Optimized molecular structures for nanokaolinite dehydration and dehydroxylation toward the formation of nanometakaolinite [dataset](MSU ScholarWorks, 2017-03) Szilagyi, Robert K.; Taborosi, AttilaThe data depository contains XYZ atomic positional coordinates for all relevant structures to describe the dry-grinding, mechanochemical activation of nanokaolinite. During this process the kaolinite undergo dehydration, followed by edge dehydroxylation, dissociation of the surface trapped water, and finally dehydroxylation of the surface hydroxides. The overall five step procedure results in amorphous metakaolinite particle with highly activated surface sites. The theoretical results are in close correlation with SEM/TEM, FTIR, and TG/DTG experimental measurements.Item Computational models for dual Cu sites in Pseudoazurin from Achromobacter cycloclastes (AcPAz) [dataset](Montana State University ScholarWorks, 2016-09) Szilagyi, Robert K.Atomic positional coordinates (XYZ), computational log files (OUT), and binary (CHK) and formatted (FCHK) checkpoint files for electronic structure calculations are deposited. The levels of theory used in the simulations are denoted in the filenames. The full computational details can be obtained from the computational log files. The filenames are organised according to the peer reviewed publications. Fig.3 corresponds to the fully optimised inner sphere environment of the Type-1 Cu site i AcPAz for oxidised (panels A-C) and one-electron reduced (panels D-E) structures Fig.5 contains the refined structures for the oxidised axial and rhombic Type-1 Cu environment as quantum chemical refinement of the inner sphere environments in the presence of a single Cu site. Fig.6 contains the refined structures for the reduced axial and rhombic Type-1 Cu environment as quantum chemical refinement of the inner sphere environments in the presence of a single Cu site. This dataset was originally posted in September 2016; it was updated with additional files in January 2017. Additional electronic supporting information are also available upon request from the corresponding authors at szilagyi@montana.edu or takamitsu.kohzuma.qbs@vc.ibaraki.ac.jp