Metal-air batteries are attracting increasing attention as a superior renewable energy conversion device due to their high performance and strong potential. However, the high cost and low stability of the current Pt catalyst is the main obstacle preventing wide industrial application. In this work, we applied a plasma process to fabricate aniline and a transition metals electrode (Fe, Co, Ni) as the carbon-nitrogen and the metal nanoparticle (NP) precursors, respectively, for selective metal/amino-N-doped carbon catalysts. All three as-synthesized catalysts exhibited dominant amino-N as the major C-N bonding state. In electrochemical testing, Co/amino-N-doped carbon showed positive E potential (0.83 V vs. Reversible Hydrogen Electrode (RHE)). In addition, the calculated electron transfer number (n) of Co/amino-N-doped carbon at 0.5 V vs. RHE was 3.81, which was only slightly less than that of commercial Pt/C (3.97). This superior performance of transition metal/amino-N-doped carbon promotes it as an economical oxygen reduction reaction (ORR) electrocatalyst to replace expensive Pt/C in metal-air batteries.
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http://dx.doi.org/10.3390/nano9050742 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720.
Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C-H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from (PMO9E).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 10120, Thailand.
A single-component flavin-dependent halogenase, AetF, has emerged as an attractive biocatalyst for catalyzing halogenation. However, its flavin chemistry remains unexplored and cannot be predicted due to its uniqueness in sequence and structure compared to other flavin-dependent monooxygenases. Here, we investigated the flavin reactions of AetF using transient kinetics.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, China.
Age-related macular degeneration (AMD), characterized by choroidal neovascularization (CNV), is the global leading cause of irreversible blindness. Current first-line therapeutics, vascular endothelial growth factor (VEGF) antagonists, often yield incomplete and suboptimal vision improvement, necessitating the exploration of novel and efficacious therapeutic approaches. Herein, a supramolecular engineering strategy to construct moringin (MOR) loaded α-cyclodextrin (α-CD) coated nanoceria (M@CCNP) is constructed, where the hydroxy and newly formed carbonyl groups of α-CD interact with the nanoceria surface via O─Ce conjunction and the isothiocyanate group of MOR inserts deeply into the α-CD cavity via host-guest interaction.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
The Fe-N-C catalyst, featuring a single-atom Fe-N configuration, is regarded as one of the most promising catalytic materials for the oxygen reduction reaction (ORR). However, the significant activity difference under acidic and alkaline conditions of Fe-N-C remains a long-standing puzzle. In this work, using extensive ab initio molecular dynamics (AIMD) simulations, we revealed that pH conditions influence ORR activity by tuning the surface charge density of the Fe-N-C surface, rather than through the direct involvement of HO or OH ions.
View Article and Find Full Text PDFCells
January 2025
Groupe de Recherche en Signalisation Cellulaire (GRSC), Département de Biologie Médicale, Université du Québec à Trois-Rivières, 3351 Boulevard des Forges, Trois-Rivières, QC G8Z 4M3, Canada.
Elevated glucose levels at the fetal-maternal interface are associated with placental trophoblast dysfunction and increased incidence of pregnancy complications. Trophoblast cells predominantly utilize glucose as an energy source, metabolizing it through glycolysis in the cytoplasm and oxidative respiration in the mitochondria to produce ATP. The TGFβ1/SMAD2 signaling pathway and the transcription factors PPARγ, HIF1α, and AMPK are key regulators of cell metabolism and are known to play critical roles in extravillous trophoblast cell differentiation and function.
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