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Cobalt-based catalysts are recognized as promising electrocatalysts for oxygen reduction reactions (ORRs) in fuel cells that operate within acidic electrolytes. A synthesis process involving a cobalt complex, nanocellulose, and dopamine, followed by pyrolysis at 500 °C under a nitrogen atmosphere, was used to create a cobalt and nitrogen-doped carbonaceous material. Additionally, urea was incorporated to enhance nitrogen doping in the carbonaceous material. The morphology and structure of the material were examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), where SEM unveiled dispersed metal oxides within the carbonaceous framework. Energy Dispersive X-ray Spectroscopy (EDS) analysis showed an even distribution of elements across the cobalt-doped carbonaceous material. X-ray Photoelectron Spectroscopy (XPS) analysis further highlighted significant alterations in the elemental composition due to pyrolysis. The electrochemical behavior of the cobalt-doped carbonaceous material, with respect to the oxygen reduction reaction (ORR) in an acidic medium, was investigated via cyclic voltammetry (CV), revealing an ORR peak at 0.30 V against a reversible hydrogen reference electrode, accompanied by a notably high current density. The catalyst’s performance was evaluated across different pH levels and with various layers deposited, showing enhanced effectiveness in acidic conditions and a more pronounced reduction peak with uniformly applied electrode layers. Rotating disk electrode (RDE) studies corroborated the mechanism of a four-electron reduction of oxygen to water, emphasizing the catalyst’s efficiency. 

A C-N cross-coupling approach involving oxidative amidations of aromatic aldehydes in the presence of an amide-based nickel(II) pincer catalyst (2) is demonstrated. Upon optimization, quick reaction times (15 min) and an ideal temperature (25 °C) were established and implemented for the conversion of 33 different amide products using only 0.2 mol% of catalyst. Moderate to good turnover numbers (TONs) were obtained for secondary benzamide products, and moderate TONs were obtained for tertiary benzamide products, with the highest turnover number calculated for the 4-chloro-N-(3-phenylpropyl)benzamide product (4i, 309). Gas chromatographic–mass spectrometric (GC–MS) analysis also indicates the formation of alcohols in different reactions, indicating an oxidative amidation process. Kinetic studies were performed by varying the amount of catalyst, aldehyde, LiHMDS base, and amine substrate to determine the order of reaction for each component. Benzaldehyde and benzaldehyde-d6 were reacted with benzylamine, and the kH/kD ratio was determined to understand the rate-determining step. Isotope labeling further revealed that deuterium was being transferred to both the alcohol side product and the target amide product. With the help of kinetic data and UV–visible spectra, a mechanism for the amidation process via the catalyst (2) is proposed through a Ni(I)–Ni(III) pathway. 

Abstract The semiconductor tracker (SCT) is one of the tracking systems for charged particles in the ATLAS detector. It consists of 4088 silicon strip sensor modules.During Run 2 (2015–2018) the Large Hadron Collider delivered an integrated luminosity of 156 fb -1 to the ATLAS experiment at a centre-of-mass proton-proton collision energy of 13 TeV. The instantaneous luminosity and pile-up conditions were far in excess of those assumed in the original design of the SCT detector.Due to improvements to the data acquisition system, the SCT operated stably throughout Run 2.It was available for 99.9% of the integrated luminosity and achieved a data-quality efficiency of 99.85%.Detailed studies have been made of the leakage current in SCT modules and the evolution of the full depletion voltage, which are used to study the impact of radiation damage to the modules.