Water oxidation is a key reaction for the conversion of solar energy into chemical fuels, but effective water-oxidation catalysts are often based on rare and costly precious metals such as Pt, Ir or Ru. Developing strategies based on earth-abundant metals is important to explore critical aspects of this reaction, and to see whether different and more efficient applications are possible for energy systems. Herein, we present an approach to tuning a redox-active electrocatalyst based on the doping of molybdenum into the tungsten framework of [Co(HO)(PWO)], known as the Weakley sandwich. The Mo-doped framework was confirmed by X-ray crystallography, electrospray ionization mass spectrometry and inductively coupled plasma optical emission spectrometry studies. The doping of molybdenum into the robust Weakley sandwich framework leads to the oxidation of water at a low onset potential, and with no catalyst degradation, whereby the overpotential of the oxygen evolution reaction is lowered by 188 mV compared with the pure tungsten framework.
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http://dx.doi.org/10.1038/s41929-018-0037-1 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Aix-Marseille Université-CNRS UMR 7283, Institut de Microbiologie de la Méditerranée and Turing Center for Living Systems, Marseille 13009, France.
Despite growing awareness of their importance in soil ecology, the genetic and physiological traits of bacterial predators are still relatively poorly understood. In the course of a predator evolution experiment, we identified a class of genotypes leading to enhanced predation against diverse species. RNA-seq analysis demonstrated that this phenotype is linked to the constitutive activation of a predation-specific program.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research (NIOZ), Den Burg 1790 AB, The Netherlands.
Heterocytes, specialized cells for nitrogen fixation in cyanobacteria, are surrounded by heterocyte glycolipids (HGs), which contribute to protection of the nitrogenase enzyme from oxygen. Diverse HGs preserve in the sediment and have been widely used as evidence of past nitrogen fixation, and structural variation has been suggested to preserve taxonomic information and reflect paleoenvironmental conditions. Here, by comprehensive HG identification and screening of HG biosynthetic gene clusters throughout cyanobacteria, we reconstruct the convergent evolutionary history of HG structure, in which different clades produce the same HGs.
View Article and Find Full Text PDFACS Phys Chem Au
January 2025
University of Duisburg-Essen, Faculty of Chemistry, Theoretical Catalysis and Electrochemistry, Universitätsstraße 5, Essen 45141, Germany.
The direct conversion of dinitrogen to nitrate is a dream reaction to combine the Haber-Bosch and Ostwald processes as well as steam reforming using electrochemistry in a single process. Regrettably, the corresponding nitrogen oxidation (NOR) reaction is hampered by a selectivity problem, since the oxygen evolution reaction (OER) is both thermodynamically and kinetically favored in the same potential range. This opens the search for the identification of active and selective NOR catalysts to enable nitrate production under anodic reaction conditions.
View Article and Find Full Text PDFThe James Webb Space Telescope has discovered a surprising population of bright galaxies in the very early Universe (≲500 Myr after the Big Bang) that is hard to explain with conventional galaxy-formation models and whose physical properties are not fully understood. Insight into their internal physics is best captured through nebular lines, but at these early epochs, the brightest of these spectral features are redshifted into the mid-infrared and remain elusive. Using the mid-infrared instrument onboard the James Webb Space Telescope, here we present a detection of Hα and doubly ionized oxygen ([O iii] 4959,5007 Å) from the bright, ultra-high-redshift galaxy candidate GHZ2/GLASS-z12.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.
Electrochemical oxidation of small molecules shows great promise to substitute oxygen evolution reaction (OER) or hydrogen oxidation reaction (HOR) to enhance reaction kinetics and reduce energy consumption, as well as produce high-valued chemicals or serve as fuels. For these oxidation reactions, high-valence metal sites generated at oxidative potentials are typically considered as active sites to trigger the oxidation process of small molecules. Isolated atom site catalysts (IASCs) have been developed as an ideal system to precisely regulate the oxidation state and coordination environment of single-metal centers, and thus optimize their catalytic property.
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