Search Results (133)

Low-temperature methanation technology offers a promising pathway for carbon recycling and sustainable energy storage by enabling near-equilibrium CO₂ conversion under atmospheric pressure. However, efficiently activating CO₂ at low temperatures remains a significant challenge due to the kinetic limitations of hydrogenation intermediates. We construct a composite oxide–metal interface structure by anchoring highly dispersed CeCrO_x nanoclusters onto metallic nickel via an ion-exchange method. This catalyst exhibits superior activity compared to conventional Ni/oxide catalysts with identical composition. Under atmospheric pressure at 220 °C, it achieves nearly 80% CO₂ conversion with over 99% methane selectivity and maintains excellent catalytic performance and structural stability during a 240-h continuous test. Systematic characterizations, including high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, CO₂ temperature-programmed desorption, and in situ DRIFTS reflectance infrared Fourier-transform spectroscopy, reveal that the synergistic modification by CeO₂ and Cr₂O₃ not only optimizes the electronic structure of Ni to promote CO₂ adsorption and activation, but also enhances H₂ dissociation and intermediate conversion by regulating oxygen vacancy concentration and alkaline site distribution. Mechanistic studies indicate that the reaction follows a synergistic mechanism dominated by the formate pathway and assisted by the CO pathway. Moreover, the interfacial structure effectively stabilizes active sites and inhibits carbon deposition from CH₄ decomposition. This study provides a universal and effective strategy for designing Ni-based CO₂ conversion catalysts suited for mild reaction conditions and characterized by high energy efficiency. Full article

The selective transformation of biomass-derived feedstocks into value-added chemicals via targeted C-O bond cleavage remains challenging due to the presence of multiple reducible bonds and typically low catalytic selectivity. Herein, we report a robust non-noble metal CoCe catalyst for the selective ring-opening hydrogenolysis of 2-furoic acid (2-FA), an industrialized biomass-derived platform molecule, to 5-hydroxypentanoic acid (5-HVA) and its derivatives, which have potential applications as fuel additives. The optimized 90CoCe catalyst with inverse phase demonstrates superior catalytic performance, achieving a total yield of more than 85% for 5-HVA and its derivatives under mild reaction conditions (130 °C, 2 MPa H₂). Extensive characterizations reveal that the inverse-phase 90CoCe catalyst possesses abundant oxygen vacancies at the Co-CeO_x interface, with the formation of Co-Ov-Ce interfacial species. The interfacial Co-Ov-Ce sites serve as specific adsorption centers for the 2-FA molecule, orienting it into a titled adsorption configuration that is highly favorable for the C₂-O₁ bond cleavage in the furan ring. Meanwhile, adjacent Co⁰ sites efficiently dissociate hydrogen into active hydrogen species for the hydrogenolysis of the C₂-O₁ bond to form ring-opening products. The synergistic balance between the hydrogenation Co⁰ sites and the interfacial Co-Ov-Ce adsorption sites is crucial to the high catalytic activity and selectivity of the CoCe catalyst. Moreover, the 90CoCe catalyst maintains stable catalytic performance during a 40 h continuous test in a fixed-bed reactor, demonstrating its great potential for industrial applications. Full article

In zinc electrowinning, industrial Pb-Ag anodes have inherent limitations, including high oxygen evolution overpotential and rapid corrosion. This study constructs Ti-Ti₂N-PbO₂-CeMnO_x composite anodes to overcome these shortcoming, Electrochemical characterization revealed enhanced performance with a reduced overpotential (725 mV 50 mA cm⁻²) and lower Tafel slope (102.92 mV dec⁻¹) in the standard zinc electrowinning electrolyte, indicating faster oxygen evolution kinetics compared to commercial benchmarks. Analysis of the XPS test revealed an increase in the content of Mn³⁺, which helps enhance the OER catalytic activity of the electrode. The Ti/Ti₂N/α/β-PbO₂-CeMnO_x (abbreviation: CMO) composite anode exhibited superior corrosion resistance with an extended service life of 53 h under accelerated polarization at 2 A cm⁻². This durability enhancement is attributed to the combined effects of the Ti₂N interlayer and CMO incorporation, which effectively mitigate anode degradation through passivation inhibition. The developed fabrication strategy enables the production of dimensionally stable anodes (DSAs) with balanced electrocatalytic activity and operational stability, showing promising potential for industrial zinc electrowinning applications. Full article

Trace amounts of CO in H₂-rich gas can poison Pt electrodes in proton-exchange-membrane fuel cells, necessitating selective CO removal. Preferential oxidation of CO (PROX) offers an efficient route to oxidize CO while preserving H₂. Although noble-metal-based catalysts are widely used, their high cost has driven interest in non-precious alternatives. Co₃O₄–CeO₂ catalysts have emerged as particularly promising due to their high activity and stability. Two series of Co–Ce/SiO₂ catalysts were prepared via impregnation: in the first, Ce was introduced and calcined prior to Co deposition; in the second, Co and Ce nitrates were co-deposited from a mixed aqueous solution. The latter method enhances the interaction between Co₃O₄ and CeO₂, increasing the availability of surface oxygen species. Stability tests on the most active sample demonstrated remarkable durability, maintaining near-complete CO conversion over 100 h on dry stream. Full article

Nanomaterial-based hole transport layers (HTLs) play a vital role in regulating interfacial charge extraction and recombination in perovskite solar cells (PSCs). To improve PSC efficiency, hydrothermally synthesized CeO₂@MoS₂ nanocomposites (CM NCs) were incorporated as an interfacial buffer layer into a NiO_X/MeO-2PACz HTL. The introduction of CM NCs induces strong interfacial interactions, where Mo sites in MoS₂ interact with NiO_X, modulating the Ni²⁺/Ni³⁺ ratio and reducing the interfacial trap density. Moreover, CeO₂ promotes the formation of oxygen vacancies, collectively improving the conductivity and hole transport capability of the NiO_X HTL. The MoS₂-grafted CeO₂ interlayer effectively tailors the interfacial energetics and creates an effective channel for hole transfer, thereby reducing open-circuit voltage (V_OC) loss and enhancing device performance. This interface modification efficiently enhances hole extraction, and non-radiative recombination is effectively suppressed at the NiO_X/MeO-2PACz/perovskite interface. Thereby, incorporating 2 vol% CM NCs into PSCs achieved a power conversion efficiency (PCE) of 17.93%, compared to 17.50% for a 1 vol% CM NCs-based device and 17.01% for the unmodified control device. The enhanced performance at the optimized CM NCs concentration is attributed to effective defect passivation, reduced V_OC loss, and improved interfacial band alignment, which together facilitate hole extraction and suppress non-radiative recombination. However, excessive CM NCs incorporation (4 vol%) leads to increased interfacial resistance, partial hole blocking effects associated with the n-type nature of CeO₂, and aggravated recombination, resulting in degraded device performance. These results demonstrate that precise control over CM NCs interlayer thickness and concentration is critical for maximizing device performance, providing a robust strategy for designing high-efficiency and stable NiO_X-based PSCs and advancing nanocomposite-enabled interfacial engineering for photovoltaic applications. Full article

Background: Atherosclerosis (AS) serves as the primary pathological basis for cardiovascular disease-related deaths worldwide, posing a severe threat to public health security. Heat shock protein 90 (HSP90) plays a crucial regulatory role in the pathological progression of AS, emerging as a potential target for anti-atherosclerosis drug development in recent years. Calenduloside E (CE) is a pentacyclic triterpenoid saponin isolated from Aralia elata (Miq.) Seem. Previous studies have confirmed its anti-atherosclerotic activity, but its weak efficacy and narrow therapeutic index limit its clinical application. In this study, the CE scaffold was hybridized with a ticagrelor-derived fragment to enhance anti-atherosclerotic activity. In this study, the CE scaffold was hybridized with a ticagrelor fragment to achieve improved activity. Methods: Based on the principle of molecular hybridization, CE was linked to the active fragment of ticagrelor via a PEG chain. Ten CE derivatives were synthesized by modifying the sugar substituents. In vitro experiments were conducted to detect cytotoxicity and protective activity against ox-LDL-induced HUVECs injury. Molecular docking and Surface Plasmon Resonance (SPR) assays were used to evaluate the interaction between CE derivatives and the known target HSP90β. Combined with Microscale Thermophoresis (MST), SwissTargetPrediction, and molecular docking, other potential targets of CE derivatives were identified. Results: In the ox-LDL-induced HUVECs injury model, all compounds except C2 and C9 exhibited protective activity. Among these compounds, compound C5 exhibited the optimal protective effect, with an EC₅₀ value of 1.44 μM. Molecular docking results revealed that both C5 and CE could bind to HSP90β by forming hydrogen bonds with the key amino acid Asp93. Additionally, SPR results indicated that C5 and CE had similar binding affinities to HSP90β, with dissociation constants (K_D) of 1.73 μM and 1.72 μM, respectively. MST demonstrated that C5 binds to HSP90β with an affinity 111 times higher than that of ticagrelor. SwissTargetPrediction and molecular docking identified P2Y12 as another potential target of derivative C5. Conclusions: Compound C5 exerts protective effect against ox-LDL-induced HUVECs injury by targeting HSP90β. Its effective concentration is significantly improved compared with that of the parent CE, which provides a possibility for reducing clinical dosage and toxic side effects in subsequent studies. Furthermore, C5 may exert its effects by targeting another potential target, P2Y12, offering references for the rational design of novel anti-atherosclerotic drugs. Full article

The continuous tightening of emission regulations and the escalating costs of palladium (Pd) and rhodium (Rh) have renewed interest in platinum (Pt)-based three-way catalysts (TWCs) as cost-effective alternatives for gasoline aftertreatment. However, despite extensive studies on Pt/CeO₂ and Pt/Ba-based formulations, the cooperative roles of Ba and Ce and, in particular, the fundamental influence of the Ba/Ce ratio on oxygen mobility, NO_x storage behavior, and Pt–support interactions remain poorly understood. In this work, we address this gap by systematically tuning the Ba/Ce molar ratio in a series of Pt–Ba–Ce/Al₂O₃ catalysts prepared from Ba(CH₃COO)₂ and CeO₂ precursors, and evaluating their structure–function relationships in both fresh and hydrothermally aged states. Through comprehensive characterization (N₂ physisorption, XRD, XPS, H₂-TPR, NO_x-TPD, SEM, CO pulse adsorption, and dynamic light-off testing), we establish previously unrecognized correlations between Ba/Ce ratio–dependent structural evolution and TWC performance. The results reveal that the Ba/Ce ratio exerts a decisive control over catalyst textural properties, Pt dispersion, and interfacial Pt–CeO₂ oxygen species. Low Ba/Ce ratios uniquely promote Pt–Ce interfacial oxygen and O₂ spillover—providing a new mechanistic basis for enhanced low-temperature oxidation and reduction reactions—while higher Ba loading selectively drives BaCO₃ formation and boosts NO_x storage capacity. A clear volcano-type dependence of NO_x storage on the Ba/Ce ratio is demonstrated for the first time. Hydrothermal aging at 850 °C induces PtO_x decomposition, BaCO₃–Al₂O₃ solid-state reactions forming inactive BaAl₂O₄, and Pt sintering, collectively suppressing Pt–Ce interactions and reducing TWC activity. Importantly, an optimized Ba/Ce ratio is shown to mitigate these degradation pathways, offering a new design principle for thermally durable Pt-based TWCs. Overall, this study provides new mechanistic insight into Ba–Ce cooperative effects, establishes the Ba/Ce ratio as a critical and previously overlooked parameter governing Pt–support interactions and NO_x storage, and presents a rational strategy for designing cost-effective, hydrothermally robust Pt-based alternatives to Pd/Rh commercial TWCs. Full article

Background: Recent studies have shown that plant-based dietary extracts can prevent the formation of lipid droplets (LDs) and oxidized lipid droplets (oxLDs) in liver cells. These results indicate that these extracts might be useful in addressing metabolic dysfunction-associated fatty liver disease (MAFLD) and its more severe form, metabolic dysfunction-associated steatohepatitis (MASH). In our ongoing study, we evaluated the potential of various food extracts to inhibit the accumulation and oxidation of LDs in liver cells to prevent metabolic MAFLD and MASH. Methods: The antioxidant activity index was determined using the DPPH assay, cell viability was assessed via cytotoxicity and lipotoxicity, and lipid droplet accumulation inhibition (LDAI) assays were performed. Metabolome analysis was performed using 1D-NMR [¹H, ¹³C, DEPT 90, and 135] techniques. Results: Dietary clove (Syzygium aromaticum) extract exhibited antioxidant properties and inhibited linoleic acid-induced lipid droplet (LD) accumulation (LDA) and oxidized LDA (oxLDA) in HepG2 cells. Additionally, an analysis of the metabolome of dietary clove bioactive LDAI using 1D-NMR showed that clove extract (CE) mainly consists of hydroxybenzoic acids (HBAs) and hydroxycinnamic acids (HCAs), along with minor amounts of carbohydrates, coumarins, polyphenolic compounds, and small quantities of polyols, fatty acyls, small peptides, and amino acids. This suggests that CE could be a promising resource for developing functional foods and nutraceuticals and discovering drugs for treating MAFLD, MASH, and related conditions. 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

In this experiment, NiCo₂O_x catalysts, with different elements added (Mg, Fe, Cu, and Ce), were prepared using the co-precipitation method to investigate their catalytic performance for carbon monoxide, as well as their water resistance and sulfur resistance. Combined with the sintering flue gas environment of Baosteel Zhanjiang Iron and Steel Co., Ltd., it provides a reference for the catalytic oxidation of CO in complex environments. The results reveal that the Fe-added catalysts exhibited a better CO catalytic performance and possessed good redox properties, and the Fe metal ion-added NiCo₂O_x catalysts showed a CO catalytic efficiency of 91.72% at 100 °C. Meanwhile, the Fe-added catalysts had the strongest resistance to water, with a conversion of 98.37% to CO at 140 °C, and with 10% water vapor. The Ce-added catalyst showed a better SO₂ resistance and hybrid resistance of SO₂ and H₂O. Under the condition of sulfur addition, the CO conversion of the Ce-added catalyst was as high as 63.07% after 4 h of SO₂ introduction, and the efficiency could be restored to 100% after cutting off the supply of SO₂. Under the conditions of sulfur addition and water addition, the CO conversion of the catalyst was 98.23% after cutting off the SO₂. Full article

A Pt@CeLaCoNiOx/Co@SnO₂ laminated MOS sensor was prepared using Co@SnO₂ as the gas-sensitive film material and Pt@CeLaCoNiOx as the catalytic film material. The sensor was verified to exhibit good sensing performances for dimethyl methylphosphonate, a simulant of Sarin, under a temperature modulation, and characteristic peaks appeared in the resistance response curves only for dimethyl methylphosphonate. The Article Swarm Optimization-Backpropagation Neural Network had a good ability to identify the resistance response data of dimethyl methylphosphonate. The identification accuracy increased as the concentration of dimethyl methylphosphonate increased. This scheme can effectively identify whether the test gas contained dimethyl methylphosphonate or not, which provided a reference for achieving the high selectivity of the MOS sensor for Sarin. Full article

A metal-doped modified CO oxidation catalyst with strong adsorption and water resistance for coalbed methane was prepared by the CO precipitation method. The CO ablation characteristics were tested, and the Cu Mn catalyst synthesized by metal Ce doping achieved an instantaneous ablation efficiency of 80% when in contact with CO at room temperature. By analyzing the surface crystal structure and pore characteristics, as well as by testing the ablation properties, it was found that the CO oxidation catalyst synthesized by Ce had the best effect at a precipitation temperature of 70 °C. A water-resistant CO oxidation catalyst was synthesized by adding polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). After storage at a relative humidity of 90%, it still had a CO adsorption rate of about 85%. The water-resistant CO oxidation catalyst prepared with polyvinyl alcohol (PVA) as an additive had a higher content of CeO₂ crystal nuclei, and the PVA-added CO oxidation catalyst had the best ablation characteristics. In the evaluation of the water-resistant steam ablation process, the CuMnO_x-Ce-PVA catalyst showed a significant increase in intermediate products during the stress process under water vapor conditions and a decrease in the peak value of the catalyst’s binding to water, and the catalyst has a particular inhibitory influence on the adsorption of water molecules on its surface. Due to its outstanding water resistance, the catalyst was able to retain good ablation characteristics. Full article

In an O₂-containing environment, achieving efficient selective catalytic reduction of nitrogen oxides (NOx) by carbon monoxide (CO) using non-noble metal catalysts remains a formidable challenge. To balance the catalytic oxidation of CO and the catalytic reduction of NOx, we need to develop a catalyst with strong reductibility and weak oxidizability for the CO selective catalytic reduction of NOx (CO-SCR) reaction in the presence of O₂. In this study, we synthesized the CoCeOx-PVP catalyst via a coprecipitation method and employed various characterization techniques, including BET, SEM, XRD, Raman, XPS, H₂-TPR, and O₂-TPD. The analysis results indicate that the addition of polyvinylpyrrolidone (PVP) alters the surface structure of the catalyst, increases the particle size, and enhances the concentration of surface oxygen vacancies. These structural effects facilitate electron circulation and accelerate the migration of oxygen species, thereby improving the catalytic reduction performance of the catalyst and increasing the conversion rate of NOx. At 250 °C and with 5 vol% O₂, the conversion rates of NOx and CO can attain 98% and 96%, respectively, accompanied by a remarkable N₂ selectivity of 99%. Following a sustained reaction period of 6 h, the conversion efficiencies of both NOx and CO remain above 95%. However, during extended testing periods, as the oxygen vacancies are progressively occupied by O₂, the oxygen vacancies generated through the reduction of NO with CO fall short of sustaining the CO-SCR reaction over the long haul. Subsequently, the oxidation reactions of NO and CO come to dominate, resulting in a decline in the NOx conversion rate. Notably, the CO conversion rate still maintains 100% at this point. Based on the results of in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) experiments, we proposed a reaction mechanism for the CO-SCR process over the CoCeOx-PVP catalyst under O₂-containing conditions. This study provides an effective strategy for the application of non-noble metal catalysts in the field of CO-SCR. Although maintaining long-term activity of the catalyst remains a challenge in the presence of O₂, the catalyst in this study exhibits a slower deactivation rate compared to traditional non-noble metal catalysts. Full article

Manganese-based oxides with good redox properties exhibit high soot oxidation activity. To further enhance their catalytic performance, introducing additional metal elements into manganese-based oxides is considered an effective approach. Herein, two rare earth elements (Sm and Ce)-modified MnO_x catalysts were prepared by the co-precipitation method. The synthesized MnO_x catalyst primarily consists of the Mn₃O₄ phase, with trace amounts of Mn₅O₈. The addition of Sm or Ce maintains the predominance of the Mn₃O₄ phase, increases the proportion of Mn₅O₈, and enhances the redox properties, thereby boosting the catalytic activity for NO and soot oxidation. Notably, the coexistence of Sm and Ce achieves optimal soot oxidation activity, with T₁₀ reaching 306 °C. Comprehensive physicochemical characterization elucidates the underlying structure–performance relationships of these catalysts. Full article

Poor selectivity is one of the main bottlenecks restricting the development of metal oxide semiconductor (MOS) sensors. In this paper, using hydrogen cyanide (HCN) as the target gas, CeMnOx as the catalytic layer material and Pt@SnO₂ as the gas-sensitive layer material, we have proposed a scheme to improve the selectivity of a catalytic layer/gas-sensitive layer-laminated MOS sensor under dynamic temperature modulation. We tested HCN and 12 kinds of battlefield environment simulation gases, and the results showed that the CeMnOx/Pt@SnO₂ sensor, under the condition of temperature dynamic modulation (a constant temperature of 400 °C for the gas-sensitive layer and a variable temperature of room temperature to 400 °C for the catalytic layer; the heating and cooling rates were 200 °C/s, the highest temperature was maintained for 2 s, and the lowest temperature was maintained for 2 s), distinct characteristic peaks appeared on the G-T curves of the resistance response to HCN only. The quantification of the characteristic peaks was performed by peak heights, and the peak height of 5 mg/m³ HCN was obtained up to 0.104, while the peak heights of the other gases at the same concentration were up to 0.034. The peak height of HCN was significantly higher than that of other gases, which verified the high selectivity of the sensor for HCN. Meanwhile, the sensor also showed good sensitivity, response/recovery time, stability and anti-interference for HCN under the above temperature dynamic modulation. This work provides an important reference for the selectivity improvement of MOS sensors for HCN. Full article