Precious-metal-free spinel oxide electrocatalysts are promising candidates for catalyzing the oxygen reduction reaction (ORR) in alkaline fuel cells. In this theory-driven study, we use joint density functional theory (JDFT) in tandem with supporting electrochemical measurements to identify a novel theoretical pathway for the ORR on cubic CoO nanoparticle electrocatalysts, which aligns more closely with experimental results than previous models. The new pathway employs the cracked adsorbates *(OH)(O) and *(OH)(OH), which, through hydrogen bonding, induce spectator surface *H. This results in an onset potential closely matching experimental values, in stark contrast to the traditional ORR pathway, which keeps adsorbates intact and overestimates the onset potential by 0.7 V. Finally, we introduce electrochemical strain spectroscopy (ESS), a groundbreaking strain analysis technique. ESS combines ab initio calculations with experimental measurements to validate the proposed reaction pathways and pinpoint rate-limiting steps.
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http://dx.doi.org/10.1021/jacs.3c11977 | DOI Listing |
J Am Coll Cardiol
January 2025
SKL-ESPC & SEPKL-AERM, College of Environmental Sciences and Engineering, Center for Environment and Health, Peking University, Beijing, China; Research Station of Alpine Ecology Environment and Health at Tibet University, Lhasa, Tibet Autonomous Region, China. Electronic address:
Background: Epidemiological studies reported associations between ozone (O) exposure and cardiovascular diseases, yet the biological mechanisms remain underexplored. Hypoxia is a shared pathogenesis of O-associated diseases; therefore, we hypothesized that O exposure may induce changes in hypoxia-related markers, leading to adverse cardiovascular effects.
Objectives: This study aimed to investigate associations of short-term O exposure with hypoxic biomarkers and arterial stiffness.
Dalton Trans
January 2025
A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 119334, Vavilova Str., 28, bld. 1, Moscow, Russia.
A low oxygen level in solid tumors is behind the modern concept of selective chemotherapy by hypoxia-activated prodrugs, such as heteroleptic complexes of transition metals (cobalt(III), iron(III) or platinum(IV)) with bi- or tetradentate ligands and an anticancer drug molecule as a co-ligand. A series of new cobalt(III) complexes [Co(LR)(esc)]ClO with esculetin (6,7-dihydroxycoumarin) and 2,2'-bipyridines (2,2'-bipy) functionalized by different substituents R were probed in the hypoxia-activated delivery of this model anticancer drug. Their combined study by cyclic voltammetry and NMR spectroscopy allowed identifying linear correlations of the electrochemical reduction potentials and the rate of the hypoxia-activated dissociation of [Co(LR)(esc)]ClO with the Hammett constants of the substituents in 2,2'-bipy ligands.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), Beijing 100190, China.
The mechanical effects on carbon-based metal-free catalysts (C-MFCs) have rarely been explored, despite the global interest in C-MFCs as substitutes for noble metal catalysts. Stress is ubiquitous, whereas its dedicated study is severely restricted due to its frequent entanglement with other structural variables, such as dopants, defects, and interfaces in catalysis. Herein, we report a proof-of-concept study by establishing a platform to continuously apply strain to a highly oriented pyrolytic graphite (HOPG) lamina, simultaneously collecting electrochemical signals.
View Article and Find Full Text PDFMed Sci (Basel)
January 2025
Faculty of Medicine, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina.
Background: CPAP has been shown to be particularly beneficial in the management of acute cardiogenic pulmonary edema by reducing both preload and afterload, thus decreasing the work of breathing and improving oxygenation.
Methods: This study was a prospective observational study, conducted in the period from 2022 to 2024, assessing the effectiveness and safety of prehospital CPAP therapy use in patients with acute cardiogenic pulmonary edema, administered alongside standard care.
Results: In this study, 50 patients with acute cardiogenic pulmonary edema were treated by physician-led emergency teams in the Canton of Sarajevo.
Inorg Chem
January 2025
Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, P. R. China.
The development of robust and effective photoanodes is crucial for photoelectrochemical hydrogen production via total water splitting. Herein, the TaO/α-FeO/Co-Ni PBA (TFPB-1) photoanode was constructed by the compositing n-type TaO and n-type α-FeO followed by the deposition of p-type Co-Ni PBA. The IPCE of TFPB-1 was increased to 35.
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