skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations

Abstract

The authors investigated the interaction of oxometalloporphyrins (MO(por))--specifically, MoO(por), WO(por), TiO(por), VO(por), and CrO(por)--with O{sub 2} by using first principles calculations. MoO(por) and WO(por) undergo reactions with O{sub 2}; on the other hand, TiO(por), VO(por), and CrO(por) do not. Next, they compared the interaction of MoO(por) and WO(por) with O{sub 2}. Activation barriers for the reactions of MoO(por) and WO(por) with a side-on O{sub 2} are small. For MoO(por)(O{sub 2}), the activation barrier for the reverse reaction that liberates O{sub 2} is also small; however, that for WO(por)(O{sub 2}) is large. The experimental results that photoirradiation with visible light or heating of Mo {sup VI}O(tmp)(O{sub 2}) regenerates Mo {sup VI}O(tmp) by liberating O{sub 2} while W {sup VI}O(tmp)(O{sub 2}) does not [J. Tachibana, T. Imamura, and Y. Sasaki, Bull. Chem. Soc. Jpn. 71, 363 (1998)] are explained by the difference in activation barriers of the reverse reactions. This means that bonds formed between the W atom and O{sub 2} are stronger than those between the Mo atom and O{sub 2}. The bond strengths can be explained by differences in the energy levels between the highest occupied molecular orbital of MoO(por) and WO(por), which are mainly formed from the a orbitalsmore » of the central metal atom and {pi}{sup *} orbitals of O{sub 2}.« less

Authors:
; ; ; ;  [1];  [2];  [2]
  1. Department of Precision Science and Technology and Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
20991269
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 126; Journal Issue: 19; Other Information: DOI: 10.1063/1.2733645; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHEMICAL BONDS; CHROMIUM COMPOUNDS; ENERGY LEVELS; MOLYBDENUM COMPOUNDS; ORGANOMETALLIC COMPOUNDS; PHOTOCHEMISTRY; PORPHYRINS; REACTION KINETICS; STABILITY; TITANIUM OXIDES; TUNGSTEN COMPOUNDS; VANADIUM OXIDES

Citation Formats

Kubota, Yoshiyuki, Escano, Mary Clare Sison, Dy, Eben Sy, Nakanishi, Hiroshi, Kasai, Hideaki, Power Engineering Research and Development Center, Research and Development Department, Kansai Electric Power Co., Inc., Amagasaki, Hyogo 661-0974, and Department of Precision Science and Technology and Applied Physics, Osaka University, Suita, Osaka 565-0871. A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations. United States: N. p., 2007. Web. doi:10.1063/1.2733645.
Kubota, Yoshiyuki, Escano, Mary Clare Sison, Dy, Eben Sy, Nakanishi, Hiroshi, Kasai, Hideaki, Power Engineering Research and Development Center, Research and Development Department, Kansai Electric Power Co., Inc., Amagasaki, Hyogo 661-0974, & Department of Precision Science and Technology and Applied Physics, Osaka University, Suita, Osaka 565-0871. A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations. United States. doi:10.1063/1.2733645.
Kubota, Yoshiyuki, Escano, Mary Clare Sison, Dy, Eben Sy, Nakanishi, Hiroshi, Kasai, Hideaki, Power Engineering Research and Development Center, Research and Development Department, Kansai Electric Power Co., Inc., Amagasaki, Hyogo 661-0974, and Department of Precision Science and Technology and Applied Physics, Osaka University, Suita, Osaka 565-0871. Mon . "A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations". United States. doi:10.1063/1.2733645.
@article{osti_20991269,
title = {A study on the stability of O{sub 2} on oxometalloporphyrins by the first principles calculations},
author = {Kubota, Yoshiyuki and Escano, Mary Clare Sison and Dy, Eben Sy and Nakanishi, Hiroshi and Kasai, Hideaki and Power Engineering Research and Development Center, Research and Development Department, Kansai Electric Power Co., Inc., Amagasaki, Hyogo 661-0974 and Department of Precision Science and Technology and Applied Physics, Osaka University, Suita, Osaka 565-0871},
abstractNote = {The authors investigated the interaction of oxometalloporphyrins (MO(por))--specifically, MoO(por), WO(por), TiO(por), VO(por), and CrO(por)--with O{sub 2} by using first principles calculations. MoO(por) and WO(por) undergo reactions with O{sub 2}; on the other hand, TiO(por), VO(por), and CrO(por) do not. Next, they compared the interaction of MoO(por) and WO(por) with O{sub 2}. Activation barriers for the reactions of MoO(por) and WO(por) with a side-on O{sub 2} are small. For MoO(por)(O{sub 2}), the activation barrier for the reverse reaction that liberates O{sub 2} is also small; however, that for WO(por)(O{sub 2}) is large. The experimental results that photoirradiation with visible light or heating of Mo {sup VI}O(tmp)(O{sub 2}) regenerates Mo {sup VI}O(tmp) by liberating O{sub 2} while W {sup VI}O(tmp)(O{sub 2}) does not [J. Tachibana, T. Imamura, and Y. Sasaki, Bull. Chem. Soc. Jpn. 71, 363 (1998)] are explained by the difference in activation barriers of the reverse reactions. This means that bonds formed between the W atom and O{sub 2} are stronger than those between the Mo atom and O{sub 2}. The bond strengths can be explained by differences in the energy levels between the highest occupied molecular orbital of MoO(por) and WO(por), which are mainly formed from the a orbitals of the central metal atom and {pi}{sup *} orbitals of O{sub 2}.},
doi = {10.1063/1.2733645},
journal = {Journal of Chemical Physics},
number = 19,
volume = 126,
place = {United States},
year = {Mon May 21 00:00:00 EDT 2007},
month = {Mon May 21 00:00:00 EDT 2007}
}
  • The crystal structure, electronic, magnetic properties and inter-atomic bonding in recently synthesized five-component Fe-containing oxychalcogenides Ca{sub 4}Fe{sub 2}Cu{sub 2}Ch{sub 2}O{sub 6}, where Ch are S or Se, which unlike all other related materials contain Fe atoms in 2D perovskite-like oxide blocks (Ca{sub 4}Fe{sub 2}O{sub 6}), were probed by means of first-principle FLAPW-GGA calculations. We found that these materials can be characterized as antiferromagnetic ionic semiconductors, composed of alternating non-magnetic chalcogenide blocks (Cu{sub 2}Ch{sub 2}) and antiferromagnetic oxide blocks (Ca{sub 4}Fe{sub 2}O{sub 6}) with S-AFM spin configuration for Fe sublattice; the interaction between these building blocks is ionic. Moreover, our resultsmore » reveal that for these materials the formation of 'natural multiple quantum wells' can be expected - like it has been found for more simple four-component LnCuOCh phases. This feature (unique for five-component Fe-containing phases) originates from 2D density of states and quantum size effects in these layered materials. - Graphical abstract: The scheme of energy band structures for Ca{sub 4}Fe{sub 2}Cu{sub 2}S{sub 2}O{sub 6} in the near-Fermi region. The band gap values are given. Highlights: Black-Right-Pointing-Pointer Very recently the new oxychalcogenides Ca{sub 4}Fe{sub 2}Cu{sub 2}Ch{sub 2}O{sub 6} were synthesized. Black-Right-Pointing-Pointer Electronic, magnetic properties for these phases were probed from first principles. Black-Right-Pointing-Pointer These materials are characterized as antiferromagnetic ionic semiconductors. Black-Right-Pointing-Pointer For these materials the 'natural multiple quantum wells' are predicted. Black-Right-Pointing-Pointer Bonding includes ionic and covalent contributions and is highly anisotropic.« less
  • The surface stability of all possible terminations for three low-index (111, 110, 100) structures of the spinel MgAl2O4 has been studied using first-principles based thermodynamic approach. The surface Gibbs free energy results indicate that the 100_AlO2 termination is the most stable surface structure under ultra-high vacuum at T=1100 K regardless of Al-poor or Al-rich environment. With increasing oxygen pressure, the 111_O2(Al) termination becomes the most stable surface in the Al-rich environment. The oxygen vacancy formation is thermodynamically favorable over the 100_AlO2, 111_O2(Al) and the (111) structure with Mg/O connected terminations. On the basis of surface Gibbs free energies for bothmore » perfect and defective surface terminations, the 100_AlO2 and 111_O2(Al) are the most dominant surfaces in Al-rich environment under atmospheric condition. This is also consistent with our previously reported experimental observation. This work was supported by a Laboratory Directed Research and Development (LDRD) project of the Pacific Northwest National Laboratory (PNNL). The computing time was granted by the National Energy Research Scientific Computing Center (NERSC). Part of computing time was also granted by a scientific theme user proposal in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), which is a U.S. Department of Energy national scientific user facility located at PNNL in Richland, Washington.« less
  • One route to decreasing the absorption in CdS buffer layers in Cu(In,Ga)Se 2 and Cu 2ZnSn(S,Se) 4 thin-film photovoltaics is by alloying. Here we use first-principles calculations based on hybrid functionals to assess the energetics and stability of quaternary Cd, Zn, O, and S (Cd 1–xZn xO yS 1–y) alloys within a regular solution model. Our results identify that full miscibility of most Cd 1–xZn xO yS 1–y compositions and even binaries like Zn(O,S) is outside typical photovoltaic processing conditions. Finally, the results suggest that the tendency for phase separation of the oxysulfides may drive the nucleation of other phasesmore » such as sulfates that have been increasingly observed in oxygenated CdS and ZnS.« less
  • By using first-principles calculations, we investigate the structural stability of nitrogen-doped (N-doped) graphene with graphitic-N, pyridinic-N and pyrrolic-N, and the transition metal (TM) atoms embedded into N-doped graphene. The structures and energetics of TM atoms from Sc to Ni embedded into N-doped graphene are studied. The TM atoms at N{sub 4}V {sub 2} forming a 4N-centered structure shows the strongest binding and the binding energies are more than 7 eV. Finally, we investigate the catalytic performance of N-doped graphene with and without TM embedding for O{sub 2} dissociation, which is a fundamental reaction in fuel cells. Compared to the pyridinic-N,more » the graphitic-N is more favorable to dissociate O{sub 2} molecules with a relatively low reaction barrier of 1.15 eV. However, the catalytic performance on pyridinic-N doped structure can be greatly improved by embedding TM atoms, and the energy barrier can be reduced to 0.61 eV with V atom embedded. Our results provide the stable structure of N-doped graphene and its potential applications in the oxygen reduction reactions.« less
  • The reaction of Re{sub 2}O{sub 7} with XeF{sub 6} in anhydrous HF provides a convenient route to high-purity ReO{sub 2}F{sub 3}. The fluoride acceptor and Lewis base properties of ReO{sub 2}F{sub 3} have been investigated leading to the formation of [M][ReO{sub 2}F{sub 4}] [M = Li, Na, Cs, N(CH{sub 3}){sub 4}], [K][Re{sub 2}O{sub 4}F{sub 7}], [K][Re{sub 2}O{sub 4}F{sub 7}]{center_dot}2ReO{sub 2}F{sub 3}, [Cs][Re{sub 3}O{sub 6}F{sub 10}], and ReO{sub 2}F{sub 3}(CH{sub 3}CN). The ReO{sub 2}F{sub 4}{sup {minus}}, Re{sub 2}O{sub 4}F{sub 7}{sup {minus}}, and Re{sub 3}O{sub 6}F{sub 10{sup {minus}} anions and the ReO{sub 2}F{sub 3}(CH{sub 3}CN) adduct have been characterized in the solidmore » state by Raman spectroscopy, and the structures [Li][ReO{sub 2}F{sub 4}], [K][Re{sub 2}O{sub 4}F{sub 7}], [K][Re{sub 2}O{sub 4}F{sub 7}]{center_dot}2ReO{sub 2}F{approximately}3}, [Cs][Re{sub 3}O{sub 6}F{sub 10}], and ReO{sub 3}F(CH{sub 3}CN){sub 2}{center_dot}CH{sub 3}CN have been determined by X-ray crystallography. The structure of ReO{sub 2}F{sub 4}{sup {minus}} consists of a cis-dioxo arrangement of Re-O double bonds in which the Re-F bonds trans to the oxygen atoms are significantly lengthened as a result of the trans influence of the oxygens. The Re{sub 2}O{sub 4}F{sub 7}{sup {minus}} and Re{sub 3}O{sub 6}F{sub 10}{sup {minus}} anions and polymeric ReO{sub 2}F{sub 3} are open chains containing fluorine-bridged ReO{sub 2}F{sub 4} units in which each pair of Re-O bonds are cis to each other and the fluorine bridges are trans to oxygens. The trans influence of the oxygens is manifested by elongated terminal Re-F bonds trans to Re-O bonds as in ReO{sub 2}F{sub 4}{sup {minus}} and by the occurrence of both fluorine bridges trans to Re-O bonds. Fluorine-19 NMR spectra show that ReO{sub 2}F{sub 4}{sup {minus}}, Re{sub 2}O{sub 4}F{sub 7}{sup {minus}}, and ReO{sub 2}F{sub 3}(CH{sub 3}CN) have cis-dioxo arrangements in CH{sub 3}CN solution. Density functional theory calculations at the local and nonlocal levels confirm that the cis-dioxo isomers of ReO{sub 2}F{sub 4}{sup {minus}} and ReO{sub 2}F{sub 3}(CH{sub 3}CN), where CH{sub 3}CN is bonded trans to an oxygen, are the energy-minimized structures. The adduct ReO{sub 3}F(CH{sub 3}CN){sub 2}{center_dot}CH{sub 3}CN was obtained by hydrolysis of ReO{sub 2}F{sub 3}(CH{sub 3}CN), and was shown by X-ray crystallography to have a facial arrangement of oxygen atoms on rhenium.« less