Exploring the Photocatalytic Efficiency of Gold Nanoparticles Deposited on Ni-Al-Zr-Layered Double Hydroxides for Selective Glucose Oxidation.

Confronting escalating challenges in energy security and environmental sustainability has intensified interest in renewable sources for fuels and chemicals. Among the most promising alternatives, sugars derived from biomass are emerging as a cornerstone in advancing an environmentally sustainable economy. Within this framework, the development of sunlight-driven carbohydrate oxidation is of significant interest, as it enables the production of a broad spectrum of high-value, bio-sourced chemicals through eco-friendly processes.

Multifunctional Heterogeneous Cobalt Catalyst for the One-Pot Synthesis of Benzimidazoles by Reductive Coupling of Dinitroarenes with Aldehydes in Water.

The endeavor of sustainable chemistry has led to significant advancements in green methodologies aimed at minimizing environmental impact while maximizing efficiency. Herein, a straightforward synthesis of benzimidazoles by reductive coupling of o-dinitroarenes with aldehydes is reported for the first time in aqueous media while using a non-noble metal catalyst. This work demonstrates that the combination of nitrogen and phosphorous ligands in the synthesis of supported heteroatom-incorporated Co nanoparticles is crucial for obtaining the desired benzimidazoles.

Role of Interfacial Hydrogen in Ethylene Hydrogenation on Graphite-Supported Ag, Au, and Cu Catalysts.

A combined surface science/microreactor approach was applied to examine interface effects in ethylene hydrogenation on carbon-supported Ag, Au, and Cu nanoparticle catalysts. Turnover frequencies (TOFs) were substantially higher for supported catalysts than for (unsupported) polycrystalline metal foils, especially for Ag. Spark ablation of the corresponding metals on highly oriented pyrolytic graphite (HOPG) and carbon-coated grids yielded nanoparticles of around 3 nm size that were well-suited for characterization by X-ray photoelectron spectroscopy (XPS), high-resolution (scanning) transmission electron microscopy (HRTEM/STEM), and energy dispersive X-ray spectroscopy (EDX).

Highly Stable Subnanometric PtIn Clusters for the Selective Dehydrogenation of Alkanes.

Subnanometric PtIn clusters have been synthesized within pure silica MFI zeolites by post-synthetic incorporation of In to Pt@K-MFI. The optimized PtIn@K-MFI catalyst outcompetes state-of-the-art PtSn formulations in ethane and propane dehydrogenations, avoiding the need of large excess of Pt promoters and harsh reductive conditions.

Exploring Reversible Redox Behavior in the 6H-BaFeO (0 < δ < 0.4) System: Impact of Fe/Fe Ratio on CO Oxidation.

This work is devoted to evaluating the relationship between the oxygen content and catalytic activity in the CO oxidation process of the 6H-type BaFeO system. Strong evidence is provided about the improvement of catalytic performance with increasing Fe average oxidation state, thus suggesting the involvement of lattice oxygen in the catalytic process. The compositional and structural changes taking place in both the anionic and cationic sublattices of the catalysts during redox cycles have been determined by temperature-resolved neutron diffraction.

Composite MAX phase/MXene/Ni electrodes with a porous 3D structure for hydrogen evolution and energy storage application.

MXenes, a family of two-dimensional (2D) transition metal carbides, have been discovered as exciting candidates for various energy storage and conversion applications, including green hydrogen production by water splitting. Today, these materials mostly remain interesting objects for in-depth fundamental studies and scientific curiosity due to issues related to their preparation and environmental stability, limiting potential industrial applications. This work proposes a simple and inexpensive concept of composite electrodes composed of molybdenum- and titanium-containing MAX phases and MXene as functional materials.

Heterogeneity Among Countries in the Subspecialty of Cardiovascular Anesthesia in Latin America: Survey Results.

Objectives: To evaluate demographics, workload, training, facilities, and equipment in cardiovascular anesthesia (CVA) in Latin America (LA).

Design: A descriptive cross-sectional study with data collected through a survey.

Setting: A multicenter, international web-based questionnaire that included 37 multiple-choice questions.

Temperature-driven evolution of ceria-zirconia-supported AuPd and AuRu bimetallic catalysts under different atmospheres: insights from IL-STEM studies.

The evolution of the structure and composition of the system of particles in two CeZrO-supported bimetallic catalysts based on Au and a 4d metal (Ru or Pd) under high temperature conditions and different reducing and oxidizing environments has been followed by means of Identical Location Scanning Transmission Electron Microscopy (IL-STEM). As an alternative to microscopy, this technique offers valuable insights into the structural modifications occurring in chemical environments with the characteristics of a macro-scale reactor. By tracking exactly the same areas on a large number of metallic entities, it has been possible to reveal the influence of particle size and the nature of the redox environment on the temperature-driven mobilization of the different metals involved.

Quantitative 3D Characterization of Functionally Relevant Parameters in Heavy-Oxide-Supported 4d Metal Nanocatalysts.

Accurate 3D nanometrology of catalysts with small nanometer-sized particles of light 3d or 4d metals supported on high-atomic-number oxides is crucial for understanding their functionality. However, performing quantitative 3D electron tomography analysis on systems involving metals like Pd, Ru, or Rh supported on heavy oxides (e.g.

Quantitative, Spectro-kinetic Analysis of Oxygen in Electron-Beam Sensitive, Multimetallic Oxide Nanostructures.

The oxygen stoichiometry of hollandite, KxMnO2-δ, nanorods has been accurately determined from a quantitative analysis of scanning-transmission electron microscopy (STEM) X-Ray Energy Dispersive Spectroscopy (XEDS) experiments carried out in chrono-spectroscopy mode. A methodology combining 3D reconstructions of high-angle annular dark field electron tomography experiments, using compressed-sensing algorithms, and quantification through the so-called ζ-factors method of XEDS spectra recorded on a high-sensitivity detector has been devised to determine the time evolution of the oxygen content of nanostructures of electron-beam sensitive oxides. Kinetic modeling of O-stoichiometry data provided K0.

Supported Ce/Zr pyrochlore monolayers as a route to single cerium atom catalysts with low temperature reducibility.

The combination of structural characterization at atomic resolution, chemical data, and theoretical insights has revealed the unique nanostructures which develop in ceria supported on yttria-stabilized zirconia (YSZ) after being submitted to high-temperature reducing treatments. The results show that just a small ceria loading is needed for creating a supported Zr-rich pyrochlore (111) nanostructure, resembling the structure of single cerium atom catalysts. The specific atomic arrangement of this nanostructure allows to explain the improvement of the reducibility at low temperature.

Gold nanoparticle-coated apoferritin conductive nanowires.

Gold-metallic nanofibrils were prepared from three different iso-apoferritin (APO) proteins with different Light/Heavy (L/H) subunit ratios (from 0% up to 100% L-subunits). We show that APO protein fibrils have the ability to nucleate and grow gold nanoparticles (AuNPs) simultaneously assembled on opposite strands of the fibrils, forming hybrid inorganic-organic metallic nanowires. The AuNPs are arranged following the pitch of the helical APO protein fiber.

Stability and Reversible Oxidation of Sub-Nanometric Cu Metal Clusters: Integrated Experimental Study and Theoretical Modeling.

Sub-nanometer metal clusters have special physical and chemical properties, significantly different from those of nanoparticles. However, there is a major concern about their thermal stability and susceptibility to oxidation. In situ X-ray Absorption spectroscopy and Near Ambient Pressure X-ray Photoelectron spectroscopy results reveal that supported Cu clusters are resistant to irreversible oxidation at least up to 773 K, even in the presence of 0.

Repairing and Preventing Photooxidation of Few-Layer Black Phosphorus with β-Carotene.

Few-layer black phosphorus (FLBP), a technologically important 2D material, faces a major hurdle to consumer applications: spontaneous degradation under ambient conditions. Blocking the direct exposure of FLBP to the environment has remained the key strategy to enhance its stability, but this can also limit its utility. In this paper, a more ambitious approach to handling FLBP is reported where not only is FLBP oxidation blocked, but it is also repaired postoxidation.

Magneto-optical hyperthermia agents based on probiotic bacteria loaded with magnetic and gold nanoparticles.

Probiotic bacteria were used as carriers of metallic nanoparticles to develop innovative oral agents for hyperthermia cancer therapy. Two synthetic strategies were used to produce the different therapeutic agents. First, the probiotic bacterium was simultaneously loaded with magnetic (MNPs) and gold nanoparticles (AuNPs) of different morphologies to produce AuNP + MNP-bacteria systems with both types of nanoparticles arranged in the same layer of bacterial exopolysaccharides (EPS).

Encapsulation of Cynara Cardunculus Guaiane-type Lactones in Fully Organic Nanotubes Enhances Their Phytotoxic Properties.

The encapsulation of bioactive natural products has emerged as a relevant tool for modifying the poor physicochemical properties often exhibited by agrochemicals. In this regard, natural guaiane-type sesquiterpene lactones isolated from L. have been encapsulated in a core/shell nanotube@agrochemical system.

Direct assessment of confinement effect in zeolite-encapsulated subnanometric metal species.

Subnanometric metal species confined inside the microporous channels/cavities of zeolites have been demonstrated as stable and efficient catalysts. The confinement interaction between the metal species and zeolite framework has been proposed to play the key role for stabilization, though the confinement interaction is elusive to be identified and measured. By combining theoretical calculations, imaging simulation and experimental measurements based on the scanning transmission electron microscopy-integrated differential phase contrast imaging technique, we have studied the location and coordination environment of isolated iridium atoms and clusters confined in zeolite.

Exceptional Low-Temperature CO Oxidation over Noble-Metal-Free Iron-Doped Hollandites: An In-Depth Analysis of the Influence of the Defect Structure on Catalytic Performance.

A family of iron-doped manganese-related hollandites, K Mn Fe O (0 ≤ ≤ 0.15), with high performance in CO oxidation have been prepared. Among them, the most active catalyst, KMnFeO(OH), is able to oxidize more than 50% of CO at room temperature.

Enhanced Artificial Enzyme Activities on the Reconstructed Sawtoothlike Nanofacets of Pure and Pr-Doped Ceria Nanocubes.

In this work, a simple one-step thermal oxidation process was established to achieve a significant surface increase in {110} and {111} nanofacets on well-defined, pure and Pr-doped, ceria nanocubes. More importantly, without changing most of the bulk properties, this treatment leads to a remarkable boost of their enzymatic activities: from the oxidant (oxidase-like) to antioxidant (hydroxyl radical scavenging) as well as the paraoxon degradation (phosphatase-like) activities. Such performance improvement might be due to the thermally generated sawtoothlike {111} nanofacets and defects, which facilitate the oxygen mobility and the formation of oxygen vacancies on the surface.

One-Step Encapsulation of -Disulfides in Functionalized Zinc MOF. Enabling Metal-Organic Frameworks in Agriculture.

Application of natural products as new green agrochemicals with low average lifetime, low concentration doses, and safety is both complex and expensive due to chemical modification required to obtain desirable physicochemical properties. Transport, aqueous solubility, and bioavailability are some of the properties that have been improved using functionalized metal-organic frameworks based on zinc for the encapsulation of bioherbicides (-disulfides). An method has been applied to achieve encapsulation, which, in turn, led to an improvement in water solubility by more than 8 times after 2-hydroxypropyl-β-cyclodextrin HP-β-CD surface functionalization.

Tutorial: structural characterization of isolated metal atoms and subnanometric metal clusters in zeolites.

The encapsulation of subnanometric metal entities (isolated metal atoms and metal clusters with a few atoms) in porous materials such as zeolites can be an effective strategy for the stabilization of those metal species and therefore can be further used for a variety of catalytic reactions. However, owing to the complexity of zeolite structures and their low stability under the electron beam, it is challenging to obtain atomic-level structural information of the subnanometric metal species encapsulated in zeolite crystallites. In this protocol, we show the application of a scanning transmission electron microscopy (STEM) technique that records simultaneously the high-angle annular dark-field (HAADF) images and integrated differential phase-contrast (iDPC) images for structural characterization of subnanometric Pt and Sn species within MFI zeolite.

Graphene-TiO hybrids for photocatalytic aided removal of VOCs and nitrogen oxides from outdoor environment.

Outdoor and indoor air pollution has become a global concern in modern society. Although many policies and regulations on air quality have been promulgated worldwide over the past decades, airborne pollution still negatively affects health and therefore the life-style of human beings. One of the strategies to challenge this problem might be reducing the amount of airborne pollutant by mineralising them photoinduced reactions.