Oxide Support Research Articles

The Role of Selected Flavonoids in Modulating Neuroinflammation in Alzheimer’s Disease: Mechanisms and Therapeutic Potential

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, amyloid-β (Aβ) deposition, tau hyperphosphorylation, oxidative stress, and chronic neuroinflammation. Growing evidence highlights neuroinflammation—driven by microglial activation and pro-inflammatory cytokine release—as a key contributor to AD pathogenesis and progression. In the absence of effective disease-modifying therapies, attention has turned to natural compounds with multi-target potential. Flavonoids, a diverse class of plant-derived polyphenols, have demonstrated neuroprotective properties through antioxidant activity, modulation of neuroinflammatory pathways, and interference with both Aβ aggregation and tau pathology. This narrative review provides an integrative overview of current findings on the mechanisms of action of key flavonoids—such as quercetin, luteolin, and apigenin—in both preclinical and clinical models. Emphasis is placed on their effects on microglial polarization, oxidative stress reduction, mitochondrial support, and synaptic function enhancement. Moreover, flavonoids show synergistic potential when combined with standard pharmacotherapies, such as acetylcholinesterase inhibitors, and may offer broader cognitive benefits in patients with mild cognitive impairment (MCI). Despite these promising findings, significant challenges persist, including poor bioavailability, inter-individual variability, and limited long-term clinical data. This review identifies critical gaps in knowledge and outlines future directions, including targeted drug delivery systems, biomarker-guided personalization, and long-duration trials. Flavonoids thus emerge not only as promising neuroprotective agents but also as complementary candidates in the development of future multi-modal strategies for AD treatment.

The impact of oxide support on the reaction mechanism of copper-based catalysts for CO2 activation

The impact of oxide support on the reaction mechanism of copper-based catalysts for CO2 activation

Predicting Adhesion Energies of Late Transition Metal Nanoparticles to Oxide Support Surfaces Using Oxide Reducibility and Metal Oxophilicity: Toward Predicting Catalyst Performance

Predicting Adhesion Energies of Late Transition Metal Nanoparticles to Oxide Support Surfaces Using Oxide Reducibility and Metal Oxophilicity: Toward Predicting Catalyst Performance

Oxide Support Inert in Its Interaction with Metal but Active in Its Interaction with Oxide and Vice Versa.

Supported metal or oxide nanostructures catalyze many industrial reactions, where the interaction of metal or oxide overlayer with its support can have a substantial influence on catalytic performance. In this work, we show that small Pt species can be well stabilized on CeO2 under both H2-containing and O2-containing atmospheres but sintering happens on SiO2, indicating that CeO2 is active whereas SiO2 is inert in Pt-support interaction. On the other hand, Co oxide (CoOx) supported on SiO2 can maintain a low-valence Co2+ state both in air and during CO2 hydrogenation to CO, indicating a strong interaction of CoOx with SiO2. However, the CoOx overlayer has a weak interaction with CeO2 and is easily reduced to metallic Co during the CO2 hydrogenation reaction producing CH4. Thus, SiO2 is active, but CeO2 is inert for CoOx-support interaction, which is counter to the common sense from the Pt/oxide systems. Systematic studies in stability behaviors of Pt and CoOx nanocatalysts supported on various oxides show that the reducibility of the oxide supports can be used to describe the catalyst-support interaction. Oxide supports with high reducibility or low metal-oxygen bond strength interact strongly with Pt and other metals, showing high metalphilicity. Conversely, oxide supports with low reducibility or high metal-oxygen bond strength have strong interaction with CoOx and other oxides, having high oxidephilicity.

Influence of the Support Nature of Copper Catalysts on Catalytic Properties in the Hydrogenation of Fatty Acid Esters.

Copper-containing catalysts supported on different commercial oxide supports (SiO2, Al2O3, and mixed oxide supports) were prepared by the incipient wetness impregnation method and investigated for the selective hydrogenation of methyl esters (methyl butyrate, methyl hexanoate, methyl stearate) to fatty alcohols. Characterization techniques, including transmission (TEM) and scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorption-desorption isotherms, and the temperature-programmed hydrogen reduction (H2-TPR) method, were utilized and revealed the relationship between catalyst properties and its structure. The best results of catalytic activity were obtained in the presence of the Cu catalyst supported on SiO2 with co-precipitated Al2O3, where the conversion of esters was above 50% with a selectivity for the corresponding alcohols of 40-70%. This efficient and inexpensive Cu-based catalyst can be widely used in industrial production, which is conducive to promoting the development of non-precious metal catalysts in the biomass industry.

An injectable and adaptable system for the sustained release of hydrogen sulfide for targeted diabetic wound therapy by improving the microenvironment of inflammation regulation and angiogenesis.

An injectable and adaptable system for the sustained release of hydrogen sulfide for targeted diabetic wound therapy by improving the microenvironment of inflammation regulation and angiogenesis.

Galvanic Displacement Engineered Pt/Co₃O₄‐CeO₂ for High‐Efficiency Toluene Elimination at Low Temperature

AbstractThe release of volatile organic compounds (VOCs) such as formaldehyde, benzene, ethylbenzene, and toluene has escalated into a critical issue due to their severe detrimental effects on both the environment and human health. In this study, we employed Co3O4 and CeO2 as mixed oxide support to fabricate Pt/Co3O4‐CeO2 via the galvanic displacement method (Pt/CC‐GD). Pt/CC‐GD demonstrated the highest efficiency achieving 90% conversion at 169 °C compared to 198 °C for the nanoparticles loading method (Pt/CC‐NPs), 210 °C for the wet impregnation method (Pt/CC‐WI), and 244 °C for the /Co3O4‐CeO2 support (CC). This enhanced performance is attributed to the exceptional oxygen mobility and superior CO2 desorption capability over Pt/CC‐GD and robust interaction between Pt and the Co3O4‐CeO2 support. Furthermore, Pt/CC‐GD demonstrated excellent catalytic durability maintaining stable activity after calcination at 700 °C for 20 h, while Pt/CC‐NPs and Pt/CC‐WI experienced significant activity decline under the same conditions. These results suggest that galvanic deposition is a promising synthesis technique for enhancing the efficiency of VOC catalytic removal.

Three-dimensional reduced graphene oxide support from spheric CaCO3 as sacrificial template applied to in-situ growth of HKUST-1 metal-organic framework

Three-dimensional reduced graphene oxide support from spheric CaCO3 as sacrificial template applied to in-situ growth of HKUST-1 metal-organic framework

Proximity-Dependent Oxide–Support Interactions in Cobalt/Ceria-Based Catalysts for Propane Dehydrogenation

Proximity-Dependent Oxide–Support Interactions in Cobalt/Ceria-Based Catalysts for Propane Dehydrogenation

DEGIDROTSIKLIZATSIYA KATALIZATORLARINING BIFUNKSIONALLIK XUSUSIYATLARI

Cyclization products can be 5- or 6-membered ring compounds. The reactions leading to the formation of these hydrocarbons represent and -cyclization reactions. Platinum catalysts for the dehydrogenation of paraffins are highly dispersed multicomponent systems embedded in a heat-resistant oxide support with a developed surface. The concentration of platinum and promoters usually does not exceed 1% wt. The most common support is γ-alumina. Previously, similar platinum catalysts were widely used in the low-pressure reforming process. This allows us to explain the high efficiency of bimetallic aluminum-platinum dehydrogenation catalysts, which is maintained even with coke content of more than 10% by weight of the catalyst. In the synthesis of aromatic hydrocarbons based on synthetic naphtha, it was proven that the samples converted to aromatic hydrocarbons in the first pass when using the catalytic systems Cr2O7 catalyst and AlNiMo+bentonite catalyst. The combined use of these catalysts resulted in the formation of monoaromatic hydrocarbons from a mixture of naphtha hydrocarbons with a high mass fraction of n-hexane, n-heptane, and n-octane in high yield and demonstrated high selectivity for this synthesis.

Contributions of Oxide Support Reducibility for Selective Oxidation of 5-Hydroxymethylfurfural over Ag-Based Catalysts

As a type of sustainable and renewable natural source, biomass-derived 5-hydroxymethyl furfural (HMF) can be converted into high-value chemicals. This study investigated the interactions between silver (Ag) and oxide supports with varied reducibility and their contributions to tuning catalytic performance in the selective oxidation of HMF. Three representatives of manganese dioxide (MnO2), zirconium dioxide (ZrO2), and silicon dioxide (SiO2) were selected to support the Ag active sites. The catalysts were characterized by techniques such as STEM (TEM), Raman, XPS, H2-TPR, and FT-IR spectroscopy to explore the morphology, Ag dispersion, surface properties, and electronic states. The catalytic results demonstrated that MnO2 with the highest reducibility exhibited superior catalytic performance, achieving 75.4% of HMF conversion and 41.6% of selectivity for 2,5-furandicarboxylic acid (FDCA) at 120 °C. In contrast, ZrO2 and SiO2 exhibited limited oxidation capabilities, mainly producing intermediate products like FFCA and/or HMFCA. The oxidation ability of these catalysts was governed by support reducibility, because it determined the density of oxygen vacancies (Ov) and surface hydroxyl groups (OOH), and eventually influenced the catalytic activity, as demonstrated by the reaction rate: Ag/MnO2 (3214.5 molHMF·gAg−1·h−1), Ag/ZrO2 (2062.3 molHMF·gAg−1·h−1), and Ag/SiO2 (1394.4 molHMF·gAg−1·h−1). These findings provide valuable insights into the rational design of high-performance catalysts for biomass-derived chemical conversion.

Enhanced Alkaline Water Electrolysis by the Rational Decoration of RuOx with the In Situ-Grown CoFe Nanolayer.

Rational engineering of the surfaces of heterogeneous catalysts (especially the surfaces of supported metals) can endow intriguing catalytic functionalities for electrochemical reactions. However, it often requires complicated steps, and even if it does not, breaking the trade-off between activity and stability is quite challenging. Herein, we present a strategy for reconstructing supported catalysts via in situ growth of metallic nanolayers from the perovskite oxide support. When Ru-coated LaFe0.9Co0.1O3 is thermally reduced, the CoFe nanoalloy spontaneously migrates onto the Ru and greatly increases the physicochemical stability of Ru in alkaline water electrolysis. Benefiting from an 81% reduction in Ru dissolution after decoration, it operates for over 200 h without noticeable degradation. Furthermore, the underlying Ru modifies the electronic structure and surface adsorption properties of the CoFe overlayer toward reaction intermediates, synergistically catalyzing both the oxygen evolution reaction and the hydrogen evolution reaction. Specifically, the mass activity of the oxygen evolution reaction is 64.1 times greater than that of commercial RuO2. Our work highlights a way to protect inherently unstable Ru from dissolution while allowing it to influence surface kinetics from the subsurface sites in heterogeneous catalysts.

Tuning Vacancy in Metal Oxide Support to Enhance Activity and Durability of Pt Catalysts for the Methanol Oxidation Reaction

Tuning Vacancy in Metal Oxide Support to Enhance Activity and Durability of Pt Catalysts for the Methanol Oxidation Reaction

A Radical-Assisted Approach to High-Entropy Alloy Nanoparticle Electrocatalysts under Ambient Conditions.

High-entropy alloy (HEA) nanoparticles are rising as promising catalysts but face challenges in both facile synthesis and correlation of the structure with properties. Herein, utilizing the highly reductive carbon-centered isopropyl alcohol radicals generated by UV irradiation, we report a simple yet robust wet chemical method to synthesize HEA nanoparticles under ambient conditions. These isopropanol radicals verified by electron paramagnetic resonance spectroscopy impose very large overpotentials to reduce diverse metal ions into HEA nanoparticles with five to seven different elements. Specially, the PtPdIrRhAuAgCu HEA nanoparticles on a reduced electrochemical graphene oxide (rEGO) support (PtPdIrRhAuAgCu-rEGO) demonstrate superior activity for the hydrogen evolution reaction (HER) across the entire pH range, with very small overpotentials of 11, 30, and 31 mV to deliver a current density of -10 mA cm-2 in 1 M KOH, 1 M phosphate buffer saline, and 0.5 M H2SO4, respectively. The excellent HER performance of PtPdIrRhAuAgCu-rEGO surpasses that of commercial Pt/C and most contemporary HER catalysts in the literature. Density functional theory calculations using random structures mimicking the chemical disordering in PtPdIrRhAuAgCu HEA confirm its superior HER activity and imply a possible correlation between HER activity and d-band centers of the nearest atoms in a face-centered cubic hollow site.

Electrocatalytic Hydrogenation Boosted by Surface Hydroxyls-Modulated Hydrogen Migration over Nonreducible Oxides.

The migration of atomic hydrogen species over heterogeneous catalysts is deemed essential for hydrogenation reactions, a process closely related to the catalyst's functionalities. While surface hydroxyls-assisted hydrogen spillover is well documented on reducible oxide supports, its effect on widely-used nonreducible supports, especially in electrocatalytic reactions with water as the hydrogen source, remains a subject of debate. Herein, a nonreducible oxide-anchored copper single-atom catalyst (Cu1/SiO2) is designed and uncover that the surface hydroxyls on SiO2 can serve as efficient transport channels for hydrogen spillover, thereby enhancing the activated hydrogen coverage on the catalyst and favoring the hydrogenation reaction. Using electrocatalytic dechlorination as a model reaction, the Cu1/SiO2 catalyst delivers hydrodechlorination activity 42 times greater than that of commercial Pd/C. An integrated experimental and theoretical investigation elucidates that surface hydroxyls facilitate the spillover of hydrogen intermediates formed at the Cu sites, boosting the coverage of active hydrogen on the surface of the Cu1/SiO2. This work demonstrates the feasibility of surface hydroxyls acting as transport channels for hydrogen-species to boost hydrogen spillover on nonreducible oxide supports and paves the way for designing advanced selective hydrogenation electrocatalysts.

Single-Atom Metal Species as A Promoter to Enhance Heterogeneous Catalysis.

Single-atom catalysts (SACs) have emerged as a focal point of research in the field of heterogeneous catalysis. This paper reviews the progress in the studies of single atoms as promoters in various catalytic reactions, elucidating their distinctive role in comparison to the dominant active sites. We provide a discussion on the application of single-atom promoters (SAP) within host-guest systems in various catalysts, including metal oxide supported catalysts, molybdenum carbide-based catalysts, bimetallic catalysts, and others. The behavior of SAP is diverse. They often promote the formation of oxygen vacancies for oxide support, leading to local site reconstruction that creates specific reaction route. Moreover, they can also precisely modify the electronic structure of hetero-metal atomic or nanoparticle sites, then regulating the adsorption of reactants or intermediates and catalytic performance. Finally, the potential for the development of SAP is outlined, proposing novel approach for the design of SACs with enhanced activity and stability.

Ultrastable supported oxygen evolution electrocatalyst formed by ripening-induced embedding.

The future deployment of terawatt-scale proton exchange membrane water electrolyzer (PEMWE) technology necessitates development of an efficient oxygen evolution catalyst with low cost and long lifetime. Currently, the stability of the most active iridium (Ir) catalysts is impaired by dissolution, redeposition, detachment, and agglomeration of Ir species. Here we present a ripening-induced embedding strategy that securely embeds the Ir catalyst in a cerium oxide support. Cryogenic electron tomography and all-atom kinetic Monte Carlo simulations reveal that synchronizing the growth rate of the support with the nucleation rate of Ir, regulated by sonication, is pivotal for successful synthesis. A PEMWE using this catalyst achieves a cell voltage of 1.72 volts at a current density of 3 amperes per square centimeter with an Ir loading of just 0.3 milligrams per square centimeter and a voltage degradation rate of 1.33 microvolts per hour, as demonstrated by a 6000-hour accelerated aging test.

Thrifting iridium for hydrogen.

Anchoring catalysts on an engineered oxide support enables stable water electrolysis.

Biochemical profiling and antioxidant evaluation of Martynia annua and Polygonum viviparum: investigating hepatoprotective properties against abiotic stress.

The liver is the second largest organ in the body, playing a crucial role in maintaining homeostasis and regulating metabolism. However, the prevalence of liver diseases has been rising steadily due to an increase in both infectious and non-infectious factors. Medicinal plants offer a remarkable opportunity to enhance our healthcare system by addressing various diseases through their ability to control oxidative stress and support metabolic processes. This revision improves readability while retaining the original meaning. In the present study, purified methanol extracts of Martynia annua and Polygonum viviparum at different concentrations were used to explore the antioxidant and hepatoprotective potential against abiotic stress on liver cells. Firstly total flavonoids and total phenolic contents of both plants were measured and then their antioxidant activities were determined through DPPH radical scavenging activity and FRAP assay. Moreover, bioactive compounds and in vitro hepatoprotective potential among these plants were determined through LC-MS and Liver Slice Culture assay respectively. In P. viviparum high amounts of TPC and TFC were observed with maximum antioxidant potential in terms of DPPH inhibition at 84% and high ferric-reducing ability at 240 mg/mL. The presence of different phytoconstituents like Myricetin, Gallic acid, Ferulic acid, Chlorogenic acid, Sweroside, Morroniside, Echonoside, Swertiamarin and Protocatechuic acid were confirmed in M. annua and P. viviparum in LC-MS study. The maximum hepatoprotective potential in terms of minimum cytotoxicity 6% and 9% were observed in M. annua and P. viviparum respectively. It was revealed that both plants have stunning hepatoprotective properties to prevent liver from toxicants and their related complications due to high antioxidant potential and active metabolites.

Efficient reduction of highly toxic 4-nitrophenol with ultra-low platinum loading on cobalt (II, III) oxide support: Facile synthesis and high turnover frequency

Efficient reduction of highly toxic 4-nitrophenol with ultra-low platinum loading on cobalt (II, III) oxide support: Facile synthesis and high turnover frequency