An electrochemical synthesis of multilayered bimetallic Ru|Pt nanoclusters, supported on glassy carbon, is reported for the first time. The novel nanoclusters were synthesized via surface-limited redox-replacement reactions involving sacrificial Cu, deposited prior to the formation of each individual noble metal layer, in a sequential fashion. It has been shown that the Cu adlayers control the morphology and electrochemical properties of the resultant nanostructures. Sequentially deposited Ru|Pt nanoclusters exhibited superior electrocatalytic activity (when compared to equivalent monometallic Pt and an alloy-type codeposited Pt-Ru nanostructures) with respect to methanol electrooxidation in an acidic medium. Moreover, it has been established that the electrochemical process taking place at the Ru|Pt nanoclusters followed the bifunctional mechanism. Electrokinetic studies of the oxygen reduction reaction (ORR) were also performed. Analysis of hydrodynamic linear sweep voltammetric experiments, performed at various flow rates on oxygen-saturated acidic medium, revealed that the Pt and Ru|Pt nanoclusters exhibited direct four- and two-electron ORR pathways, respectively. A specially designed electrochemical flow-cell was used for automated sequential electrodeposition of the multilayered nanoclusters of predefined composition and electrochemical and electrocatalytic investigations.
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http://dx.doi.org/10.1021/la902219t | DOI Listing |
ChemSusChem
December 2024
Department of Chemistry, Chungnam National University, Daejeon, 34134, Republic of Korea.
Catalyst design plays a critical role in ensuring sustainable and effective energy conversion. Electrocatalytic materials need to be able to control active sites and introduce defects in both acidic and alkaline electrolytes. Furthermore, producing efficient catalysts with a distinct surface structure advances our comprehension of the mechanism.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Xiamen University, Chemistry, No. 422, Simingnan Road, 361005, Xiamen, CHINA.
The presence of trace CO impurity gas in hydrogen fuel can rapidly deactivate platinum-based hydrogen oxidation reaction (HOR) catalysts due to poisoning effects, yet the precise CO tolerance mechanism remains debated. Our designed Au@PtX bifunctional core-shell nanocatalysts exhibit excellent performance of CO tolerance in acidic solution during HOR and possess exceptional Raman spectroscopy enhancement. Through capturing and analyzing in situ Raman spectroscopy evidences on *OH, metal-O species and *CO evolution under 0.
View Article and Find Full Text PDFAdv Mater
January 2025
Shenzhen Key Laboratory of Energy Electrocatalytic Materials, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering, Shenzhen University, Shenzhen, Guangdong, 518055, P. R. China.
Engineering nanomaterials at single-atomic sites can enable unprecedented catalytic properties for broad applications, yet it remains challenging to do so on RuO-based electrocatalysts for proton exchange membrane water electrolyzer (PEMWE). Herein, the rational design and construction of Bi-RuO single-atom alloy oxide (SAAO) are presented to boost acidic oxygen evolution reaction (OER), via phase engineering a novel hexagonal close packed (hcp) RuBi single-atom alloy. This Bi-RuO SAAO electrocatalyst exhibits a low overpotential of 192 mV and superb stability over 650 h at 10 mA cm, enabling a practical PEMWE that needs only 1.
View Article and Find Full Text PDFAnn Intensive Care
January 2025
Department of Anaesthesia, Intensive Care Medicine and Pain Medicine, Division of General Anaesthesia and Intensive Care Medicine, Medical University of Vienna, Vienna, Austria.
Background: Acute respiratory distress syndrome (ARDS) associated with coronavirus infectious disease (COVID)-19 has been a challenge in intensive care medicine for the past three years. Dysregulation of the renin-angiotensin system (RAS) is linked to COVID-19, but also to non-COVID-19 ARDS. It is still unclear whether changes in the RAS are associated with prognosis of severe COVID-19.
View Article and Find Full Text PDFGeroscience
January 2025
Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, 125047, Russia.
Age-related dependencies of electric and spectral powers in conventional frequency bands were studied by the newly proposed method of detailed spectral analysis. The magnetic encephalograms (MEG) and magnetic resonance images (MRI) of the head were obtained from the open archive Cam-CAN. The spatial distributions of elementary spectral components (MEG-based functional tomograms) were reconstructed from MEG for 501 subjects (248 males and 253 females, ages 18-88 years, mean age 54.
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