Search Results (756)

To enhance the purification of exhaust gas, a g-C₃N₄/CeO₂/Bi₂O₃ dual type-II heterojunction photocatalysis was designed and prepared to suppress the recombination of electron–hole pairs and improve light energy utilization. The dual type-II heterojunction structure effectively reduced the bandgap (Eg) from 2.5 eV to 2.04 eV, thereby extending the light absorption of photocatalysis into the visible region. Following the design of the heterojunction, a self-cleaning process was developed and applied to asphalt pavement rut plates to evaluate its efficiency in degrading vehicle exhaust under real-road conditions. The coating was systematically characterized in terms of exhaust degradation efficiency, hardness, adhesion, water resistance, freeze–thaw durability, and skid resistance. Under 60 min of natural light irradiation, the purification efficiencies for HC, CO, CO₂, and NO_x reached 22.60%, 19.27%, 14.83%, and 50.01%, respectively. After three-repetition tests, the efficiencies remained high at 21.75%, 19.04%, 14.66%, and 49.83%, demonstrating excellent photocatalytic stability. All other road-performance indicators met the relevant China national standards. The application of this self-cleaning coating in road infrastructure presents a viable strategy for environmental remediation in transportation systems. Full article

In the early Paleoproterozoic, the Earth’s atmosphere–ocean system shifted from a reducing to an oxidizing state, triggering the extensive deposition of banded iron formations (BIFs) in the Siderian period (2.5–2.3 Ga). As a key sedimentary formed during the hydrospheric oxidation stage, BIFs are expected to preserve abundant microbial fossils or organic carbon. However, evidence for contemporaneous widespread biological activity remains limited. This paper focuses on C-O isotopes and the trace element geochemistry of the 2.5 Ga Jining BIF to constrain the redox state of paleo-oceans and associated biogeochemical cycling during BIF deposition. The δ¹³C_carb values of the BIF samples range from −18.6‰ to −9.6‰, with an average of −12.7‰, exhibiting a notable negative value, and TOC contents (0.04–0.19 wt.%) are extremely low. This suggests the incorporation of oxidized organic carbon to pore water via ferrihydrite reduction during early diagenesis process. The globally negative δ¹³C_carb value of BIFs and iron-rich carbonates reflect enhanced biological activity at ~2.5 Ga. REE patterns reveal negative Ce/Ce*_(SN) and Eu/Eu*_(CN) anomalies, and the presence of primary hematite mesobands together indicate that the Jining BIF records a redox transition in seawater from reducing to oxidizing conditions. Full article

Incomplete diesel combustion emits soot and CO. The use of biomass-derived, oxygen-containing diesel additives has been proposed as an effective mitigation strategy. Among these, long-chain ethers have been widely regarded as one of the most promising additive classes. Guided by this, carbonyl compounds were targeted as intermediates for the synthesis of long-chain ethers. Py-GC/MS was used to assess eight oxides (CaO, ZrO₂, NiO, CeO₂, TiO₂ (rutile), TiO₂ (anatase), Fe₂O₃, CuO) during fast pyrolysis of native holocellulose. Relative content of carbonyl compounds was increased by all catalysts, with CaO exhibiting the highest value (69.47%). CaO raised the content of linear ketones from 18.25% to 27.61%, while it sharply reduced the relative content of acetic acid (from 11.56% to 3.19%). TiO₂ (rutile) increased cyclic ketones from 11.09% to 15.01%. CuO boosted furans and acids to 17.48% and 17.91%, respectively. Levoglucosan dropped from 11.24% to 4.83% over CuO, which also increased furfural content from 3.25% to 5.63%. Full article

This study examines the rheological and tribological behavior of bio-based nano-lubricants enhanced with cerium oxide (CeO₂) and multi-walled carbon nanotubes (MWCNTs), alongside the application of artificial intelligence (AI) models for performance prediction. Rheological results confirmed non-Newtonian, shear-thinning behavior across all formulations. CeO₂-based lubricants exhibited significantly higher viscosities at 40 °C (up to ~3700 mPa·s at low shear), which decreased sharply with shear, indicating strong particle interactions. In contrast, MWCNT-based lubricants maintained moderate viscosities (90–365 mPa·s at 40 °C) with improved flowability due to nanotube alignment. At 100 °C, both systems showed viscosity reduction, stabilizing between 8 and 18 mPa·s, which favors pumpability in high-temperature applications. Tribological testing revealed distinct performance characteristics. CeO₂ lubricants showed slightly higher coefficients of friction (0.144–0.169) but excellent wear resistance, achieving the lowest wear rate of 1.66 × 10⁻⁶ mm³/N-m. MWCNT-based lubricants offered stable and lower CoF values (0.116–0.148) while also providing very low wear rates, with MCO6 achieving 1.62 × 10⁻⁶ mm³/N-m. However, ternary blends (C20T80 and M20T80) displayed moderate CoF but significantly higher wear rates (up to 2.92 × 10⁻⁵ mm³/N-m), suggesting that blending improves dispersion but weakens tribo-film stability. To complement the experimental findings, support vector regression (SVR), artificial neural networks (ANN), and AdaBoost algorithms were employed to predict key performance parameters based on compositional and thermal input data. The models demonstrated high prediction accuracy, validating the feasibility of AI-driven formulation screening. These results highlight the complementary potential of CeO₂ and MWCNT additives for high-performance bio-lubricant development and emphasize the role of machine learning in accelerating material optimization for sustainable lubrication systems. Full article

Studies were conducted on the hydrogen-free processing of model alkanes, straight-run gasoline, and catalytic cracking gasoline using a new synthesized Co-Mo-Ce/ZSM + Al₂O₃ nanocatalyst, which demonstrated high activity in desulfurization. Thus, the mass fraction of sulfur in the resulting gasoline was reduced by almost three times compared to the initial value of 0.0776% to 0.0354% as a result of hydrogen-free processing of straight-run gasoline. The amount of sulfur in the resulting product was reduced by almost an order of magnitude with hydrogen-free processing of catalytic cracked gasoline: from 0.1650 in the original gasoline to 0.0123%. The octane number of the refined straight-run gasoline was 77.9–80.9 according to the research method (RM) and 61.13–65.8 with the motor method (MM). Physical and chemical methods of analysis (BET, TPD-NH₃, TEM, SEM, and XRD) revealed that nano-structured acid sites coexist with nano-dispersed metallic sites on the surface of the Co-Mo-Ce/ZSM + Al₂O₃ catalyst. The functioning of these two types of nano-active sites (metallic and acidic) ensures the polyfunctionality of the catalytic action of the nanoparticles. The following reactions occur simultaneously in the hydrogen-free processing: isomerization, dehydrogenation, dehydrocyclization. Hydrogen-free processing of low-octane gasoline fractions on nanosized zeolite-containing catalysts is one of the most promising methods to obtain high-octane motor gasoline. Full article

Cutaneous regeneration remains a major challenge in biomedicine, prompting the exploration of novel therapeutic agents such as cerium oxide nanoparticles (CeO₂ NPs, nanoceria). These nanoparticles exhibit multifaceted regenerative properties, including stimulation of metabolic and proliferative activity in keratinocytes, fibroblasts, and endothelial cells, potent antioxidant effects, immunomodulatory potential, and antimicrobial activity. Although numerous in vitro studies have characterized these properties, there is a critical need to evaluate nanoceria in more physiologically relevant in vivo settings, where dynamic biological conditions may significantly influence their efficacy. Furthermore, the therapeutic performance of CeO₂ NPs is highly dependent on the synthesis methods and formulation components (excipients and co-administered active substances). A review of existing in vivo studies investigating nanoceria-based formulations for wound healing addresses this gap. The authors found 25 relevant studies published as of September 2025 in major scientific databases, including PubMed, Scopus, the Cochrane Library, which provided data on the effectiveness of using cerium oxide nanoparticles as components of medical devices or wound dressings in accelerating wound healing in animal models. This analysis synthesizes evidence on nanoparticle efficacy, formulation strategies, and observed biological outcomes across animal models. These findings indicate that nanoceria formulations can accelerate wound closure and modulate the key phases of tissue repair, although the outcomes vary with particle characteristics and delivery systems. While nanoceria hold considerable promise for clinical wound management, standardized reporting of synthesis protocols and rigorous comparative in vivo studies are essential to translate their potential into reliable therapeutic applications. Full article

The chemical diffusion coefficients of oxygen ($D^{\delta }$) for the oxides BaFe_0.9Ce_0.1O_3−δ (BFC10), BaFe_0.9Y_0.1O_3−δ (BFY10), and BaFe_0.8Ce_0.1Y_0.1O_3−δ (BFCY1010) were determined by the oxygen pressure relaxation method in the T = 600–800 °C and pO₂ = 0.1–3.5 kPa ranges. The oxygen diffusion coefficients at 700 °C were found to be 1.80·10⁻⁵, 3.92·10⁻⁵, and 1.85·10⁻⁵ cm²/s for BFC10, BFY10, and BFCY1010, respectively. It was established that the volume oxygen diffusion increases in the order $D^{\delta }$(BFY10) > $D^{\delta }$(BFCY1010) > $D^{\delta }$(BFC10), which correlates with the data on oxygen non-stoichiometry (δ), and is associated with the oxygen vacancy content in oxides. The values of effective activation energies were determined: 1.21 ± 0.04, 1.31 ± 0.10, and 1.18 ± 0.09 eV for BFC10, BFY10, and BFCY1010, respectively. A comparative analysis of oxygen transport highlights the potential of co-doped BaFe_0.8Ce_0.1Y_0.1O_3−δ as a promising cobalt-free cathode material with triple (oxygen, proton, electron) conductivity. Full article

The industrial application of CO₂ methanation in Power-to-X (P2X) systems requires the development of highly active catalysts capable of operating at milder temperatures to ensure energy efficiency, while exhibiting high activity, stability and selectivity. This study reports the synthesis and optimization of Ni-based catalysts on Al₂O₃ supports, guided by a Design of Experiments (DoE, 2⁴ factorial design) approach. Initial optimization afforded a robust catalyst achieving 80% CO₂ conversion and >99% CH₄ selectivity at 325 °C. Remarkably, the incorporation of CeO₂ traces to the Ni-based catalyst substantially boosted catalytic activity, enabling higher conversions at temperatures up to 75 °C lower than the unpromoted catalyst. This improvement is attributed to Ni–CeO_x synergy, which facilitates CO₂ activation and Ni reducibility. Both formulations exhibited exceptional long-term stability over 100 h. Furthermore, process intensification via the Sorption-Enhanced Reaction Process (SERP) with the Ni-based catalyst demonstrated even superior efficiency, rapidly increasing CO₂ conversion beyond 95% with the same selectivity range. Our findings establish a clear and consistent pathway for industrial CO₂ valorization through next-generation P2X technology for high-purity synthetic natural gas (SNG) production. This process offers an efficient and sustainable route toward industrial defossilization by converting captured CO₂ and green H₂ into SNG that is readily usable within the existing energy infrastructure. Full article

The drive to utilize ammonia as a carbon-free hydrogen source necessitates the development of effective, non-precious metal catalysts for ammonia decomposition. We successfully synthesized a series of Ce-based perovskite oxides (CeXO₃; X = Co, Ni, Fe) via combustion method using citric acid. These catalyst precursors were tested for NH₃ decomposition to study the effect of the perovskite structure on catalytic activity. The results were directly compared to corresponding impregnated catalysts, X/CeO₂, which had similar metal concentrations. A remarkable enhancement in catalytic performance was observed with the perovskite catalysts, particularly at lower temperatures, relative to their impregnated counterparts. The exception was the CeFeO₃ catalyst, which exhibited lower activity, likely due to the formation of metal nitrides. Both CeNiO₃ and CeCoO₃ showed good NH₃ decomposition activity, but CeNiO₃ emerged as the most active catalyst at lower temperatures. This superior performance attributed to the presence of oxygen vacancies—confirmed by Raman and XPS analyses—and enhanced metal reducibility at lower temperatures, both of which accelerate NH₃ decomposition. Furthermore, CeNiO₃ also displayed a high surface metal concentration. These Ce-based perovskite materials are cost-effective, easily synthesized, and highly stable; hence, they are attractive candidates for large-scale hydrogen production. Full article

Thermal barrier coatings (TBCs) are critical for protecting hot-section components in gas turbines and aero-engines. Traditional yttria-stabilized zirconia (YSZ) coatings are prone to phase transformation and sintering-induced failure at elevated temperatures. This study fabricated CeScYSZ (4 mol% CeO₂ and 6 mol% Sc₂O₃ co-doped YSZ)/NiCrAlY TBCs using atmospheric plasma spraying (APS). A five-factor, four-level orthogonal experimental design was employed to optimize spraying parameters, investigating the influence of powder feed rate, spray distance, current, hydrogen flow rate and primary gas flow rate on the coating’s microstructure and mechanical properties. The resistance to calcium–magnesium–alumino–silicate (CMAS) corrosion was compared between CeScYSZ and YSZ coatings. The results indicate that the optimal parameters are a spray distance of 100 mm, current of 500 A, argon flow rate of 30 L/min, hydrogen flow rate of 6 L/min, and powder feed rate of 45 g/min. Coatings produced under these conditions exhibited moderate porosity and excellent bonding strength. After exposure to CMAS corrosion at 1300 °C for 2 h, the CeScYSZ coating demonstrated significantly superior corrosion resistance compared to YSZ. This enhancement is attributed to the formation of a CaZrO₃ physical barrier and the synergistic effect of Ce and Sc in suppressing deleterious phase transformations. This study provides an experimental basis for the preparation and application of high-performance TBCs. Full article

Background: In the bovine mammary gland, de novo fatty acid synthesis is a critical process for milk fat production, in which acetyl-CoA synthetase 2 (ACSS2) serves as a key enzyme by converting acetate into acetyl-CoA. This metabolic pathway is intricately regulated by non-coding RNAs, particularly through the competitive endogenous RNA (ceRNA) mechanism.Purpose: To elucidate the regulatory role and molecular mechanism of the circRNA-02213/miR-328/ACSS2 axis in the lipid metabolism of bovine mammary epithelial cells (BMECs). Methods: Bioinformatic prediction and dual-luciferase reporter assays were employed to verify the targeting interactions among circRNA-02213, miR-328, and ACSS2. In BMECs, qRT-PCR, Western blot, triglyceride/cholesterol quantification, Oil Red O staining, and cell proliferation assays were used to evaluate the effects of this axis on key lipid-metabolic indices and cellular phenotypes. Results: circRNA-02213 functioned as a molecular “sponge” that sequestered miR-328, thereby upregulating ACSS2 expression. Functionally, circRNA-02213 overexpression markedly promoted triglyceride and cholesterol synthesis, lipid droplet accumulation, and BMEC proliferation; whereas miR-328 exerted significant inhibitory effects on these lipid-metabolic processes and cell proliferation. Conclusions: This study demonstrates that circRNA-02213 acts as a ceRNA to relieve miR-328-mediated repression of ACSS2, constituting a critical network that regulates milk fat synthesis and metabolism. The circRNA-02213/miR-328/ACSS2 axis represents a potential molecular target for improving milk lipid quality in ruminants. Full article

Grapefruit is rich in flavanones, particularly naringin and narirutin. This study investigated the effects of temperature, time, and solid-to-liquid ratio on microwave-assisted pressurized CO₂–H₂O (MWP-CO₂-H₂O) extraction of flavonoids from grapefruit and optimized the parameters for maximum total flavonoid content (TFC) using response surface methodology. Independent variable ranges were 110–160 °C, 4.00–14.00 min, and 1:10.00–1:40.00 g/mL. Optimum conditions were 128 °C, 13.88 min, and 1:31.35 g/mL, yielding a TFC of 27.96 ± 1.29 mg naringin equivalent/g dry weight. Under these conditions, extraction yield, total phenolic content, ferric reducing ability of plasma, cupric reducing antioxidant capacity, and DPPH IC₅₀ were 55.17 ± 1.90% (dry basis), 25.42 ± 1.39 mg gallic acid equivalent/g, 39.16 ± 1.61 µmol trolox equivalent/g, 81.64 ± 0.29 µmol trolox equivalent/g, and 1.60 ± 0.01 mg/mL, respectively. Compared to conventional extraction (CE), MWP-CO₂-H₂O produced higher TFC, phenolic content, and antioxidant activity, while reducing extraction time by 13.68-fold. These results highlight grapefruit peel waste as a sustainable source of bioactive compounds and demonstrate that MWP-CO₂-H₂O is an environmentally sustainable, efficient alternative to conventional methods. Full article

The increasing atmospheric CO₂ concentration is one of the major environmental challenges, necessitating not only emission reduction but also effective carbon utilization. Non-thermal plasma-catalytic CO₂ conversion offers an efficient pathway under mild conditions by synergistically combining plasma activation with catalytic surface reactions. In this study, mesoporous ceria catalysts were synthesized by different methods and characterized using N₂ adsorption–desorption, SEM, XRD, XPS, CO₂-TPD, and XRF techniques. The materials exhibited distinct textural and electronic properties, including variations in surface area, pore structure, and basicity. Plasma-catalytic CO₂ dissociation experiments were conducted in a dielectric barrier discharge reactor at near-room temperature. Among the synthesized catalysts, Ce(mp)-4 demonstrated the highest CO₂ conversion of 32.3% at a 5 kV input voltage and superior energy efficiency, which can be attributed to its meso-macroporous structure that promotes microdischarge formation and enhances CO₂ adsorption–desorption dynamics. CO was the only product obtained, with near-100% selectivity. Catalyst stability testing showed no deactivation while spent catalyst characterization indicated carbon-containing species. The findings in this study highlight the critical role of tailored pore structure and basic-site distribution in optimizing plasma-catalytic CO₂ dissociation performance, offering a promising strategy for energy-efficient CO₂ utilization. Full article

The activity of Co- and Ni-containing ceria-based catalysts for water–gas shift (WGS) reaction were examined in this work. The catalysts were prepared by the urea co-precipitation method. Sm and Pr dopant (5 wt.%) was used as a structural stabilizer of CeO₂, while Co or Ni was used in a small amount (1 wt.%). H₂-TPR experiments indicate that both Sm and Pr addition increased the reducibility of CeO₂. Among the studies’ catalysts, 1%Ni/Ce5%SmO exhibited the highest WGS activity. In addition, WGS rate was measured in the temperature range of 200–400 °C for Ni supported on CeO₂, Ce5%SmO, and Ce5%PrO. The activation energy of the reaction over 1%Ni/Ce5%SmO was 57 kJ/mol, while it was 61 and 66 kJ/mol, respectively, over 1%Ni/Ce5%PrO and 1%Ni/CeO₂ catalysts. A WGS reaction mechanism, CO adsorbed on the metal cluster is oxidized by oxygen supplied from the CeO₂ support at the metal–ceria interface. This oxygen is then re-oxidized by H₂O, which caps the oxygen vacancy on the ceria surface, and thereby oxygen vacancies serve as active sites for the WGS reaction. Raman experiments indicate that the presence of Sm in 1%Ni/Ce5%SmO catalyst promoted the formation of oxygen vacancies, leading to enhanced WGS performance. Full article

The reverse water–gas shift (RWGS) reaction efficiently converts CO₂ to CO, with vital applications in carbon emission reduction and Fischer-Tropsch chemical production. This study used density functional theory (DFT) to investigate CO₂ adsorption and activation on CeO₂, oxygen-vacancy CeO₂ (CeO_2−x), and single-atom Ni-loaded CeO₂ (Ni/CeO₂). Adsorption energy analysis indicates that CO₂ preferentially adsorbs at the intermediate oxygen sites on CeO₂ and Ni/CeO₂, but on CeO_2−x, it preferentially adsorbs at the oxygen vacancies. Mulliken charge and band gap results indicate that CeO_2−x and Ni/CeO₂ exhibit higher activity than pure CeO₂. Density of states studies indicate that CeO₂, CeO_2−x, and Ni/CeO₂ can activate CO₂ to varying degrees; strong hybridization between Ni’s d-orbitals and CO₂’s O p-orbitals is key to Ni/CeO₂’s high activity. Mechanistically, CeO_2−x follows the RWGS redox mechanism, while Ni/CeO₂ follows the formate-associated mechanism. This work innovatively clarifies differential CO₂ adsorption-activation by vacancies and Ni in CeO₂-based catalysts, providing a theoretical basis for RWGS catalyst design and supporting low-energy carbon conversion development. Full article