Transition metals, such as Cu(+2), Mn(+2), and Co(+2), have been seen to catalyze the bicarbonate enhanced oxidation of a variety of substrates by H(2)O(2). In several of these cases it has been demonstrated that CO(2), rather than bicarbonate, is the enhancing species. Mechanisms that are in accord with the data involve a hypervalent state that may be written (MO)(+n), or (MOH)(+n+1), or (M)(+n+2). This metal centered oxidant then oxidizes CO(2) to the carbonate radical; that is then the proximal oxidant of the various substrates. Whether a similar process has in vivo reality remains to be demonstrated.
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http://dx.doi.org/10.1016/j.jinorgbio.2006.01.030 | DOI Listing |
Acc Chem Res
January 2025
The Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, United States.
ConspectusIn the search for efficient and selective electrocatalysts capable of converting greenhouse gases to value-added products, enzymes found in naturally existing bacteria provide the basis for most approaches toward electrocatalyst design. Ni,Fe-carbon monoxide dehydrogenase (Ni,Fe-CODH) is one such enzyme, with a nickel-iron-sulfur cluster named the C-cluster, where CO binds and is converted to CO at high rates near the thermodynamic potential. In this Account, we divide the enzyme's catalytic contributions into three categories based on location and function.
View Article and Find Full Text PDFAstrobiology
January 2025
Experimental Biophysics and Space Sciences, Department of Physics, Freie Universitaet Berlin, Berlin, Germany.
The (PSS) experiment was part of the European Space Agency's mission and was conducted on the International Space Station from 2014 to 2016. The PSS experiment investigated the properties of montmorillonite clay as a protective shield against degradation of organic compounds that were exposed to elevated levels of ultraviolet (UV) radiation in space. Additionally, we examined the potential for montmorillonite to catalyze UV-induced breakdown of the amino acid alanine and its potential to trap the resulting photochemical byproducts within its interlayers.
View Article and Find Full Text PDFEnviron Sci Process Impacts
January 2025
Department of Civil, Environmental and Architectural Engineering, University of Colorado at Boulder, Boulder, 80309, USA.
Wildfires can severely degrade soils and watersheds. Post-fire rain events can leach ashes and altered dissolved organic matter (DOM) into streams, impacting water quality and carbon biogeochemistry. The photochemical properties and persistence of DOM from wildfire ash leachates are not well understood.
View Article and Find Full Text PDFACS Cent Sci
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Inelastic photoelectron scattering (IPES) by gas molecules, a critical phenomenon observed in ambient pressure X-ray photoelectron spectroscopy (APXPS), complicates spectral interpretation due to kinetic energy loss in the primary spectrum and the appearance of additional features at higher binding energies. In this study, we systematically investigate IPES in various gas environments using APXPS, providing detailed insights into interactions between photoelectrons emitted from solid surfaces and surrounding gas molecules. Core-level XPS spectra of Au, Ag, Zn, and Cu metals were recorded over a wide kinetic energy range in the presence of CO, N, Ar, and H gases, demonstrating the universal nature of IPES across different systems.
View Article and Find Full Text PDFNat Commun
January 2025
School of Environment, Tsinghua University, Beijing, 100084, P. R. China.
Modulation of electronic spin states in cobalt-based catalysts is an effective strategy for molecule activations. Crystalline-amorphous interfaces often exhibit unique catalytic properties due to disruptions of long-range order and alterations in electronic structure. However, the mechanisms of molecule activation and spin states at interfaces remain elusive.
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