The active site for electrocatalytic water oxidation on the highly active iron(Fe)-doped β-nickel oxyhydroxide (β-NiOOH) electrocatalyst is hotly debated. Here we characterize the oxygen evolution reaction (OER) activity of an unexplored facet of this material with first-principles quantum mechanics. We show that molecular-like 4-fold-lattice-oxygen-coordinated metal sites on the (1̅21̅1) surface may very well be the key active sites in the electrocatalysis. The predicted OER overpotential (η) for a Fe-centered pathway is reduced by 0.34 V relative to a Ni-centered one, consistent with experiments. We further predict unprecedented, near-quantitative lower bounds for the η, of 0.48 and 0.14 V for pure and Fe-doped β-NiOOH(1̅21̅1), respectively. Our hybrid density functional theory calculations favor a heretofore unpredicted pathway involving an iron(IV)-oxo species, Fe=O. We posit that an iron(IV)-oxo intermediate that stably forms under a low-coordination environment and the favorable discharge of Ni to Ni are key to β-NiOOH's OER activity.
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Trends Genet
December 2024
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100, Israel. Electronic address:
Adaptation to environmental conditions occurs over diverse evolutionary timescales. In multi-cellular organisms, adaptive traits are often studied in tissues/organs relevant to the environmental challenge. We argue for the importance of an underappreciated layer of evolutionary adaptation manifesting at the cellular level.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
TCS Research, Sahyadri Park 2, Rajiv Gandhi Infotech Park, Hinjewadi Phase 3, Pune 411057, India.
Realization of a sustainable hydrogen economy in the future requires the development of efficient and cost-effective catalysts for its production at scale. MXenes (MX) are a class of 2D materials with 'n' layers of carbon or nitrogen (X) interleaved by 'n+1' layers of transition metal (M) and have emerged as promising materials for various applications including catalysts for hydrogen evolution reaction (HER). Their properties are intimately related to both their composition and their atomic structure.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Shenzhen University, Chemistry, Nanhai Ave 3688, 518060, Shenzhen, CHINA.
The high entropy alloy (HEA) possesses distinctive thermal stability and electronic characteristics, which exhibits substantial potential for diverse applications in electrocatalytic reactions. However, accurately controlling the size of HEA still remains a challenge, especially for the ultrasmall HEA nanoparticles. Herein, we firstly calculate and illustrate the size impact on the electronic structure of HEA and the adsorption energies of crucial intermediates in typical electrocatalytic reactions, such as the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), CO2 electroreduction (CO2RR) and NO3- electroreduction (NO3RR).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
University of Science and Technology of China, Hefei National Research Center for Physical Sciences at Microscale, jinzhai road, hefei, CHINA.
Herein, we first report a photocatalytic OCM using CO2 as a soft oxidant for C2H6 production under mild conditions, where an efficient photocatalyst with unique interface sites is constructed to facilitate CO2 adsorption and activation, while concurrently boosting CH4 dissociation. As a prototype, the Au quantum dots anchored on oxygen-deficient TiO2 nanosheets are fabricated, where the Au-Vo-Ti interface sites for CO2 adsorption and activation are collectively disclosed by in situ Kelvin probe force microscopy, quasi in situ X-ray photoelectron spectroscopy and theoretical calculations. Compared with single metal site, the Au-Vo-Ti interface sites exhibit the lower CO2 adsorption energy and decrease the energy barrier of the *CO2 hydrogenation step from 1.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Institute of Materials Science, Technische Universität Darmstadt, Peter-Grünberg-Str. 2, D-64287, Darmstadt, Germany.
The design of cathode/electrolyte interfaces in high-energy density Li-ion batteries is critical to protect the surface against undesirable oxygen release from the cathodes when batteries are charged to high voltage. However, the involvement of the engineered interface in the cationic and anionic redox reactions associated with (de-)lithiation is often ignored, mostly due to the difficulty to separate these processes from chemical/catalytic reactions at the cathode/electrolyte interface. Here, a new electron energy band diagrams concept is developed that includes the examination of the electrochemical- and ionization- potentials evolution upon batteries cycling.
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