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.

Download full-text PDF

Source
http://dx.doi.org/10.1021/jacs.3c11977DOI Listing

Publication Analysis

Top Keywords

oxygen reduction
8
onset potential
8
pathway
4
reduction pathway
4
pathway spinel
4
spinel metal
4
metal oxides
4
oxides alkaline
4
alkaline media
4
media experimentally
4

Similar Publications

Associations of Short-Term Ozone Exposure With Hypoxia and Arterial Stiffness.

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.

View Article and Find Full Text PDF

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 PDF

Intrinsic Mechanical Effects on the Activation of Carbon Catalysts.

J 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 PDF

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.

View Article and Find Full Text PDF

Distinct Promotion of PEC Water Oxidation of TaO/α-FeO/Co-Ni PBA via Coupling Ni 3d with O 2p.

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.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!