This study introduces a novel microspherical W-SiO2 heterogeneous catalyst for alcohol dehydration, prepared via an innovative microwave-assisted condensation synthesis method. The process involves the microwave-assisted preparation of a hybrid tungsten naphthalene dicarboxylate-based precursor solution, which is subsequently condensed with (3-aminopropyl)triethoxysilane in a single step-eliminating the need for separate silica support preparation, as required in conventional impregnation methods. After calcination at 550 degrees C, the resulting amorphous and porous microspheres contain highly dispersed tungsten species (with loadings of 2, 6, and 12 wt%), with no crystalline WO3 phase detected, even at the highest loading. Compared to a 12 wt% WO3/SiO2 catalyst prepared via conventional impregnation, the W-SiO2 microspheres exhibit higher catalytic activity and ethylene selectivity in ethanol dehydration at 420 degrees C. Notably, the 2W-SiO2 catalyst achieved the highest initial ethylene productivity per mole of tungsten (520 mmol mmolW-1 h-1), maintaining 230 mmol mmolW-1 h-1 after 1000 minutes on stream, indicating high long-term stability. In terms of mass-specific performance, the 12W-SiO2 catalyst reached 133 mmol g-1 h-1, outperforming other comparable previously reported tungsten-silica catalysts.

Nanoparticles, due to their unique size-dependent properties, distinct from those of bulk materials, have become a rapidly developing and intensively studied area of chemistry. These properties include the ability to catalyse chemical reactions, reduced melting temperatures, and distinctive optical characteristics. In this paper, we investigate these features in bimetallic Ag@Ni core-shell nanoparticles of varying composition. The nanoparticles were synthesised via a solvothermal method using silver nitrate and nickel(ii) acetylacetonate in a mixture of oleylamine and octadec-1-ene as solvents. Characterisation was carried out using a series of spectroscopic and microscopic methods. Catalytic activity and surface processes leading to the production and release of carbon dioxide were examined using Knudsen effusion mass spectrometry (KEMS). The highest catalytic activity was noted for Ag-Ni nanoparticles containing approximately 30-50 at% silver. The catalytic process is accompanied by the formation of organometallic compounds, which were detected by X-ray photoelectron spectroscopy (XPS) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). Thermal stability during heating was evaluated by differential scanning calorimetry (DSC), and a melting point depression of approximately 10 °C was observed for all studied samples. The paper is a part of a broader study of Ni-based bimetallic nanoparticles, their thermal stability and catalytic activity.

In this work, a spherical and hierarchical carbon-based nanocomposite containing dispersed cobalt nanoparticles is introduced. The preparation of this material is based on a facile microwave-assisted synthesis of a cobalt-based metal-organic framework containing a 2,6-naphthalene dicarboxylic linker (labeled as NDC) and its subsequent carbonization at either 600 degrees C or 700 degrees C in an argon atmosphere. The resulting materials exhibit unique morphology and feature small Co nanoparticles with sizes of about 3.1 and 6.0 nm, respectively, evenly dispersed on the carbon matrix. In the methanation of carbon dioxide, these CoNDC-derived nanocomposites achieved a methane formation rate of up to 10.5 mu molCH4 gcat behavior is ascribed to a high content of accessible small metallic cobalt nanoparticles present in the hierarchical structure of CoNDC nanocomposite catalysts, highlighting their promising potential for CO2 utilization in industry.

Two phenoxido-bridged dinuclear Ni(II) and Co(II) complexes, [M2(SAIDPPO)2(NO3)2] (M = Ni, Co), have been synthesized using a new Schiff base phosphine oxide ligand (SAIDPPO-). Single-crystal X-ray diffraction revealed closely related Ni2O2 and Co2O2 cores with distinct magnetostructural features. Magnetic studies showed that the Ni(II) complex (1) exhibits ferromagnetic coupling (J = +9.75 cm-1) associated with a near-orthogonal Ni-O-Ni angle (95.50 degrees) and pronounced easy-axis anisotropy (D =-19.44 cm-1). In contrast, the Co(II) analog (2) displays weak antiferromagnetic coupling (J approximate to-4.32 cm-1) combined with significant easy-axis anisotropy (D =-28.45 cm-1) arising from strong spin-orbit coupling. The comparison of the Ni2O2 and Co2O2 cores highlights how subtle structural variations, particularly the M-O-M angle, govern the balance between exchange interactions and magnetic anisotropy.

A family of three heterometallic molecular phosphonate clusters with {CoxDy} (x = 6, 7, 9) cores was synthesized using the Schiff-base-derived phosphonate ligand HSAA2-. The reactions of CoCl2·6H2O and DyCl3·6H2O with HSAA2- under various conditions afforded the polynuclear complexes [Co9Dy(SAA)6Cl3] (1), [Na2Co7Dy(SAA)6(SA)] (2), and [Na3Co6Dy(SAA)6] (3), which are based on a common {Co6Dy} phosphonate core further stabilized by additional cobalt or sodium cations. The complexes were found to be thermally stable up to 250 °C, soluble, and stable in polar aprotic solvents. Direct current (dc) magnetic susceptibility measurements recorded over the temperature range 2-300 K were interpreted using an effective-spin model. The analysis revealed an isotropic Co2+ contribution and a strong axial Dy3+ response consistent with Ising-type magnetic behavior. Despite the presence of strongly anisotropic Dy3+ centers, alternating current (ac) magnetic measurements revealed negligible slow relaxation of magnetization, even under an external magnetic field.

Boroaluminates are promising materials for various catalytic applications, particularly due to their tunable acidity and textural properties, although they have not yet reached their full potential. Developing synthetic routes that yield mesoporous structures with high surface areas is crucial for maximizing their performance. Traditional preparation methods (including hydrolytic sol-gel) often struggle to produce highly mesoporous, high-surface-area boroaluminates without the use of templating agents and can lead to heterogeneous elemental distribution. Furthermore, direct comparisons of different non-hydrolytic sol-gel (NHSG) approaches for these materials are limited. In this work, we present an NHSG preparation method for mesoporous boroaluminates, utilizing the alkyl-halide condensation reaction between Al(OiPr)3 and BCl3, with a 1:1 boron/aluminum precursor ratio. This approach resulted in amorphous xerogels featuring a homogeneous distribution of boron and aluminum atoms within the structure. Our method successfully produced mixed boria-alumina xerogels with high surface areas, reaching up to 600 m2 g−1 without the need for any templating agent. We characterized these materials using 11B and 27Al MAS NMR spectroscopy, SEM and STEM-EDS microscopy, N2 porosimetry, thermogravimetry, ICP-OES and XPS elemental analysis and ammonia-TPD. Additionally, we provide a comparative analysis with boroaluminates prepared by other non-hydrolytic sol-gel reactions and demonstrate their practical utility in catalysis through ethanol dehydration (with >83

Amorphous aluminosilicates are known for their excellent performance in (bio)ethanol dehydration for ethylene production. Several studies showed that the homogeneous dispersion of Al in amorphous aluminosilicates is the key to obtain active and stable catalysts. However, ensuring a high dispersion of Al in the aluminosilicate matrix remains a complicated task. Here, the aerosol-assisted sol-gel (AASG) process is presented as a facile one-step and continuous production method towards highly homogeneous aluminosilicates. We systematically examine the effect of the aluminum loading (1-9 wt% Al) in silica matrix incorporated via AASG technique on the catalytic activity during ethanol dehydration. Aluminum dispersion, chemical structure, textural properties, and acidic behavior were investigated by STEM-EDS, MAS NMR, XPS, nitrogen porosimetry, and infrared spectroscopy combined with pyridine adsorption. Aluminum content is shown to influence textural properties and acidity, and therefore strongly modify catalytic activity. The most active AASG-prepared aluminosilicate catalysts exhibited higher activity and on-stream stability if compared to commercial silica-alumina. It reached a similar performance to other amorphous aluminosilicates with highly homogeneous Al dispersion prepared via peculiar protocols.

Nonoxidative ethanol dehydrogenation opens a pathway for the sustainable production of acetaldehyde and butadiene. One crucial aspect of producing butadiene by the Lebedev process is the high-temperature stability of ethanol to acetaldehyde conversion. However, copper-based catalysts, despite exhibiting high activity and selectivity, suffer from sintering and coking and need to be improved for successful industrial applications. Herein, we show Cu-based (∼2.5 wt %) catalysts doped with Ni and Zn (0.028-0.36 wt %) to improve the catalytic performance of nanoparticles. The catalysts were prepared by hydrolytic sol-gel and dry impregnation methods. STEM analysis determined the nanoparticle sizes in the 1.9-2.8 nm range. Ni-doped catalysts outperformed the parent Cu catalysts in ethanol dehydrogenation activity at lower temperatures (185-220 °C) but suffered from faster deactivation. The Zn-doped catalysts exhibited improved high-temperature stability. For these materials, acetaldehyde selectivity fluctuated around ∼90% and acetaldehyde productivity reached 3.63 g g-1 h-1 at 290 °C and a WHSV of 4.73 h-1. The improved stability of the Zn-doped samples was correlated with lower coke formation (XPS, TG analysis, and Raman spectroscopy).

Olefin metathesis catalysts based on molybdenum exhibit superior performance at low temperatures when they contain highly dispersed MoOx species within the catalyst support. However, the preparation methods that achieve this high dispersion are often difficult to scale up. In this study, we report the scalable synthesis of molybdenum silicate (Mo & horbar;SiO2) nanofibers (NFs) via electrospinning, aimed at producing catalysts active in olefin metathesis reactions. The resulting NFs had diameters ranging from 70 to 209 nm and exhibited high surface areas, reaching up to 920 m(2) g(-1). A comprehensive characterization of the MoOx active sites-using powder x-ray diffraction analysis, Raman spectroscopy, x-ray photoelectron spectroscopy, HRTEM, H-2-TPR, and in situ DRUV-Vis-confirmed the absence of crystalline phases, indicating a high degree of dispersion and uniformity. Among the prepared samples, Mo & horbar;SiO2 containing 5 wt% Mo, with an average fiber diameter of 104 nm and a surface area of 456 m(2) g(-1), demonstrated exceptional catalytic performance in propylene self-metathesis. It achieved a propylene metathesis rate of 17.1 mu mol g(-1) s(-1) at 200 degrees C, significantly outperforming a catalyst prepared via incipient wetness impregnation, used here as a model for industrial benchmarks.

Plasma agriculture as a novel approach started to gain more attention in the last decade. In this work, the effect of plasma activated water (PAW) prepared with different plasma sources from three types of water on germination and growth of Cucumis melo L. was studied. The best effect of PAW from distilled water on the growth of seedlings was observed when prepared using the surface-wave-sustained microwave discharge. The effect of artificially prepared plasma activated water (ArtPAW) was studied, however, it was found that while ArtPAW may cause similar effects to the plasma PAW, the effect is not as significant and consistent. Further, PAW was prepared from tap and wastewater. It was found that PAW from wastewater has positive effects on both germination of the seeds and the growth of the seedlings. The root elongation of C. melo after application of plasma treated wastewater increased up to 130% compared to the control. Moreover, it was found that plants grown in PAW from wastewater contained significantly higher concentrations of plant nutrients. Therefore, it shows a promising approach for the application of non-thermal plasma in plant fertilization and a method of wastewater reuse after plasma treatment.

Non-oxidative ethanol dehydrogenation opens a road for sustainable production of acetaldehyde and butadiene. One crucial part of producing butadiene by the Lebedev process is high-temperature stability of ethanol-to-acetaldehyde conversion. However, copper-based catalysts, despite exhibiting high activity and selectivity, suffer from sintering and coking and need to be improved for successful industrial application. Herein, we show Cu-based (~2.5 wt%) catalysts doped by Ni and Zn (0.02−0.3 wt%) to improve the catalytic performance of nanoparticles. Catalysts were prepared by hydrolytic sol-gel and dry impregnation. STEM analysis determined nanoparticle sizes in the 1.9−2.8 nm range. Ni-doped catalysts outperformed parent Cu catalysts in ethanol dehydrogenation activity at lower temperatures (185-220 °C) but suffered from faster deactivation. Zn-doped catalysts exhibited an improved high-temperature stability. For these materials, acetaldehyde selectivity fluctuated around ~90 % and acetaldehyde productivity reached 3.63 g · g−1 · h−1 at 290 °C. The improved stability of Zn-doped samples correlated with a lower coke formation (TG analysis).

A novel, highly efficient condensation approach for the preparation of heterogeneous vanadium silicate microspherical catalyst is introduced. This synthetic method is based on a microwave-assisted preparation of hybrid vanadium biphenyl dicarboxylate-based precursor solution and subsequent condensation with (3-ami-nopropyl)triethoxysilane. The as-prepared hybrid metallosilicate is then calcined at 500 degrees C to obtain amorphous and porous vanadium silicate microspheres with highly dispersed vanadium species inserted into the silicate matrix. This catalyst with 2.85 wt% of vanadium contains evenly distributed VOx species, which possesses high catalytic activity in a cyclohexene epoxidation reaction, reaching a conversion of 54 % after 4 h with 92 % selectivity to cyclohexene oxide. The catalyst's TOF value achieved 220 h-1, indicating its high performance compared to vanadium-containing catalyst analogs. Furthermore, a significant catalytic activity of prepared vanadium silicate microspheres in ethyl lactate oxidation to ethyl pyruvate with the conversion of 21 % at mild conditions shows a high potential of the catalyst for industrial application compared to the contemporary V2O5 heterogeneous catalyst.

Porous aluminosilicates are functional materials of paramount importance as Lewis acid catalysts in the synthetic industry, yet the participating aluminum species remain poorly studied. Herein, a series of model aluminosilicate networks containing [L–AlO3] (L = THF, Et3N, pyridine, triethylphosphine oxide (TEPO)) and [AlO4]– centers were prepared through non-hydrolytic sol-gel condensation reactions of the spherosilicate building block (Me3Sn)8Si8O20 with L–AlX3 (X = Cl, Me, Et) and [Me4N] [AlCl4] compounds in THF or toluene. The substoichiometric dosage of the Al precursors ensured complete condensation and uniform incorporation, with the bulky spherosilicate forcing a separation between neighboring aluminum centers. The materials were characterized by 1H, 13C, 27Al, 29Si, and 31P MAS NMR and FTIR spectroscopies, ICP-OES, gravimetry, and N2 adsorption porosimetry. The resulting aluminum centers were resolved by 27Al TQ/MAS NMR techniques and assigned based on their spectroscopic parameters obtained by peak fitting (δiso, CQ, η) and their correspondence to the values calculated on model structures by DFT methods. A clear correlation between the decrease in the symmetry of the Al centers and the increase of the observed CQ was established with values spanning from 4.4 MHz for distorted [AlO4]– to 15.1 MHz for [THF–AlO3]. Products containing exclusively [TEPO–AlO3] or [AlO4]– centers could be obtained (single-site materials). For L = THF, Et3N, and pyridine, [AlO4]– centers were formed together with the expected [L–AlO3] species, and a viable mechanism for the unexpected emergence of [AlO4]– was proposed.

Contamination of the environment with toxic metals such as cadmium or lead is a worldwide issue. The accumulator of metals Cannabis sativa L. has potential to be utilized in phytoremediation, which is an environmentally friendly way of soil decontamination. Novel non-thermal plasma-based technologies may be a helpful tool in this process. Plasma activated water (PAW), prepared by contact of gaseous plasma with water, contains reactive oxygen and nitrogen species, which enhance the growth of plants. In this study, C. sativa was grown in a short-term toxicity test in a medium which consisted of plasma activated water prepared by dielectric barrier discharge with liquid electrode and different concentrations of cadmium or lead. Application of PAW on heavy metal contaminated C. sativa resulted in increased growth under Pb contamination as was determined by ecotoxicology tests. Furthermore, the PAW influence on the bioaccumulation of these metals as well as the influence on the nutrient composition of plants was studied primarily by applying Laser-induced breakdown spectroscopy (LIBS). The LIBS elemental maps show that C. sativa accumulates heavy metals mainly in the roots. The results present a new proof-of-concept in which PAW could be used to improve the growth of plants in heavy metal contaminated environment, while LIBS can be implemented to study the phytoremediation efficiency.

Amidst growing concerns over the environmental impact of petroleum-based industries and their contribution to global ecological challenges, there is a pressing need for sustainable alternatives in chemical synthesis. This study addresses this imperative by exploring an innovative catalytic approach for the eco-friendly production of acetaldehyde from ethanol, a crucial chemical feedstock. Catalysts utilized so far perform poorly due to their low stability. Supported copper nanoparticles at higher temperatures suffer from the rapid deactivation caused by nanoparticles sintering and reduction of active sites by coking. To address this issue, the advanced copper nanoparticle-decorated silica nanofibres (107 nm in diameter) with outstanding surface area (700 m2 g−1) were synthesized and tested, showing enhanced stability in comparison to benchmark (Aerosil 300 SiO2/Cu). Two approaches were compared for the preparation of copper catalyst, i.e., dry impregnation and one-pot synthesis. Remarkably, the dry-impregnated DI-9.4 sample at 325 °C after 100 h maintained over 66 % of ethanol conversion with 99 % selectivity to acetaldehyde (acetaldehyde productivity: 3.09 g g h–1). This stability values surpass the benchmark catalyst, which dropped to 40 % of ethanol conversion. Our findings highlight the potential of the superior morphological advantage of electrospun SiO2 nanofibers as an efficient catalyst.

Polysaccharides are often utilized as reducing and stabilizing agents and as support in the synthesis of gold nanoparticles (AuNPs). However, using approaches like spin coating or dip coating, AuNPs are generally bound to the support only by weak interactions, which can lead to decreased stability of the composite. Here, a twostage approach for the preparation of composites with covalently anchored AuNPs is proposed. First, 5 nm AuNPs with high catalytic activity for the reduction of 4-nitrophenol (TOF = 15.8 min-1) were synthesized and stabilized using fully oxidized and solubilized 2,3-dialdehyde cellulose (DAC). Next, the carbonyl groups in the shell of prepared nanoparticles were used to tether AuNPs to chitosan nanofibers with quantitative efficacy in a process that we termed "affinity anchoring". Schiff bases formed during this process were subsequently reduced to secondary amines by borohydride, which greatly improved the stability of the composite in the broad pH range from 3 to 9. The catalytic efficacy of the resulting composite is demonstrated using a model catalytic device, showing high stability, fast conversion rates, and direct reusability.

ZrN-Cu coatings containing two different amounts of Cu (~11 at.% and ~25 at.%) were deposited using an industrial physical vapor deposition (PVD) system. The as-deposited coatings exhibited 100% bactericidal efficiency against Escherichia coli CCM 3988 for an exposure time of 40 min. Subsequently, the samples were attached onto our faculty’s door handles for six months to study the coatings’ long-term effectiveness and durability under actual operational conditions. The samples were periodically evaluated and it was observed that the coatings with 25 at.% Cu performed better than the ones with 11 at.% Cu. For example, following 15 days of being touched, the bactericidal effectiveness of the sample containing 25 at.% Cu dropped to 65% while it fell to 42% for the sample containing 11 at.%. After 6 months, however, both samples showed bactericidal efficiency of ~16–20%. The bactericidal efficiency of the samples touched for 6 months was successfully restored by polishing them. Furthermore, a group of samples was kept untouched and was also evaluated. The untouched samples with Cu content of ~25 at.% did not show any drop in their bactericidal properties after 6 months. ZrN-Cu coatings were concluded to be promising materials for self-sanitizing application on high-touch surfaces.

Metallic tungsten microfibers were prepared in a multigram yield by electrospinning from the aqueous phos-photungstic acid/polyvinyl alcohol (PVA) solution in three steps. Green composite microfibers of H3PW12O40 /PVA were easily electrospun from precursor solutions on a Nanospider instrument with a cylindrical rotating electrode. Subsequent oxidation of the organic PVA matrix and decomposition of phosphotungstic acid in the air at 600 degrees C provided ceramic WO3/P2O5 fibers. Finally, prepared oxide fibers were reduced in a forming gas at-mosphere at temperatures up to 1000 degrees C. During the reduction, all phosphorus was removed, and pure metallic tungsten microfibers were produced.