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Liquid-phase transmission electron microscopy (LPTEM) is an essential tool for studying the dynamics of materials interactions at the nanoscale, in and/or with their operational environment. Microfabricated SiNx membrane cells further allow the integration of thin-film electrodes that opens the technique to studies of heterogeneous electrocatalysts under relevant electrochemical conditions. However, experiments remain challenging and the characteristics of the dedicated electrochemical cells and of the interactions of the electron beam with the liquid electrolyte demand careful interpretation of the results. Herein, we discuss important aspects that concern the implementation of electrochemical LPTEM (ec-LPTEM). We first consider the range of information that can be accessible with the technique for electrocatalytic applications and we detail the influence of the thickness and flow of liquid electrolytes using membrane-based microcells. Further, we provide guidelines pertinent to the electrochemical configuration of the substrate working, reference, and counter electrodes. We validate these considerations by experimentally demonstrating the application of ec-LPTEM for the CO2 reduction reaction (CO2RR), the oxygen reduction reaction (ORR), and the oxygen evolution reaction (OER). The probed effects in metallic and oxide catalysts are directly related to the applied electrochemical stimuli and corroborate the representativity of the processes under investigation following the considerations described herein.

The purpose of this study is to research terminology of Industry 4.0 in some of the biggest companies in Czech Republic. The main objective was to find out whether they know about the concept of Industry 4.0 and the Fourth Industrial Revolution. Further goals were to find out which terminology they use in companies, and if they have practical experience with the technologies. Qualitative research was conducted via an online questionnaire. Results have shown some terms used by scientific literature are unknown in practice and that the view of companies on this topic might be different from the view of researchers based on their responses. This calls for more in-depth research for which we present recommendations.

Understanding metal surface reconstruction during operation is of the uttermost importance in heterogeneous catalysis as it directly affects the available active sites. However, surface reconstruction is notoriously difficult to study because of the dynamic nature of the phenomena behind it. Here, we report on the mechanism and the intermediates, which drive the rearrangement of copper catalysts during the electrochemical CO2 reduction reaction. In-situ methods, including mass spectrometry and fluorescence spectroscopy, evidence a dissolution – redeposition process mediated by transient species containing copper in +1 oxidation state. Theory identifies copper-adsorbate complexes which form in solution under operating conditions. Copper carbonyls and oxalates emerge as the major reaction-specific species driving copper reconstruction. This work motivates future studies to specifically target these compounds to improve the catalyst operational stability in the electrochemical CO2 reduction reaction.

Bromination of high-pressure, high-temperature (HPHT) nanodiamond (ND) surfaces has not been explored and can open new avenues for increased chemical reactivity and diamond lattice covalent bond formation. The large bond dissociation energy of the diamond lattice-oxygen bond is a challenge that prevents new bonds from forming, and most researchers simply use oxygen-terminated NDs (alcohols and acids) as reactive species. In this work, we transformed a tertiary-alcohol-rich ND surface to an amine surface with ∼50% surface coverage and was limited by the initial rate of bromination. We observed that alkyl bromide moieties are highly labile on HPHT NDs and are metastable as previously found using density functional theory. The strong leaving group properties of the alkyl bromide intermediate were found to form diamond-nitrogen bonds at room temperature and without catalysts. This robust pathway to activate a chemically inert ND surface broadens the modalities for surface termination, and the unique surface properties of brominated and aminated NDs are impactful to researchers for chemically tuning diamond for quantum sensing or biolabeling applications.

Bromination of high-pressure high-temperature (HPHT) nanodiamond (ND) surfaces has not been explored and can open new avenues for increased chemical reactivity and diamond lattice covalent bond formation. The large bond dissociation energy of the diamond lattice-oxygen bond is a challenge that prevents new bonds from forming and most researchers simply use oxygen-terminated ND (alcohols and acids) as a reactive species. In this work, we transformed a tertiary alcohol-rich ND surface to an amine surface with 50% surface coverage and was limited by the initial rate of bromination. We observed that alkyl-bromide moieties are highly labile on NDs and are metastable as previously found using density functional theory. The instability of the bromine terminated ND is explained by steric hindrance and poor surface energy stabilization. The strong leaving group properties of the alkyl-bromide intermediate were found to form diamond-nitrogen bonds at room temperature and without catalysts. The chemical lability of the brominated ND surface led to efficient amination with NH3•THF at 298 K, and a catalyst-free Sonogashira-type reaction with an alkyne-amine produced an 11-fold increase in amination rate. Overlapping spectroscopies under inert, temperature-dependent and open-air conditions provided unambiguous chemical assignments. Amine-terminated NDs and folic acid were conjugated using sulfo-NHS/EDC coupling reagents to form amide bonds, confirming that standard amine chemistry remains viable. This work supports that a robust pathway exists to activate a chemically inert diamond surface at room temperature, which broadens the pathways of bond formation when a reactive alkyl-bromide surface is prepared. The unique surface properties of brominated and aminated nanodiamond reported here are impactful to researchers who wish to chemically tune diamond for quantum sensing applications or as an electron source for chemical transformations.

Understanding the structure and behavior of intermediates in chemical reactions is the key to developing greater control over the reaction outcome. This principle is particularly important in the synthesis of metal nanocrystals (NCs), where the reduction, nucleation, and growth of the reaction intermediates will determine the final size and shape of the product. The shape of metal NCs plays a major role in determining their catalytic, photochemical, and electronic properties and, thus, the potential applications of the material. In this work, we demonstrate that layered coordination polymers, called lamellae, are reaction intermediates in Cu NC synthesis. Importantly, we discover that the lamella structure can be fine-tuned using organic ligands of different lengths and that these structural changes control the shape of the final NC. Specifically, we show that short-chain phosphonate ligands generate lamellae that are stable enough at the reaction temperature to facilitate the growth of Cu nuclei into anisotropic Cu NCs, being primarily triangular plates. In contrast, lamellae formed from long-chain ligands lose their structure and form spherical Cu NCs. The synthetic approach presented here provides a versatile tool for the future development of metal NCs, including other anisotropic structures.