Citral, a valuable natural fragrance, suffers from chemical instability that limits its industrial application. Acetalization with 1,2-propanediol offers an effective stabilization route. Herein, we report a series of Al-P(x)-O solid acid catalysts with tunable P/Al molar ratios, synthesized via a PEG-20000-assisted one-pot method. Comprehensive characterization (XRD, FT-IR, XPS, BET, SEM, NH3-TPD, and Py-IR) reveals that the P/Al molar ratio governs a fundamental shift in acid-type distribution from purely Lewis acidity to a synergistic Lewis-Brønsted bifunctional system. The optimized Al-P(1.20)-O catalyst achieves 64.6
Catalytic methane decomposition (CMD) represents a low-carbon route for hydrogen production accompanied by the simultaneous formation of valuable carbon nanostructures. In this work, the influence of Ce and Mo promoters on the properties of Fe–Ni/TiO₂–Al₂O₃, Fe–Ni–Ce/TiO₂–Al₂O₃, and Fe–Mo–Ce/TiO₂–Al₂O₃ catalysts was investigated in CMD reactions under dry conditions and in the presence of steam at 600–850 °C. Comprehensive characterization by XRD, H₂-TPR, TPO, Raman spectroscopy, and TGA revealed that CeO₂ enhances the reducibility and oxygen mobility of Fe-Ni phases, whereas Mo is present in the form of highly dispersed MoOx species and significantly alters their redox properties. The Fe–Ni–Ce/TiO₂–Al₂O₃ catalyst exhibited the highest methane conversion (96
To overcome the drawbacks of traditional coprecipitation/impregnation methods (e.g., complex process, pollutant emission, low loading) using soluble metal salts, this work employed carbonates (MnCO3 and Ce2(CO3)3) as raw materials and oxalic acid as a chemical molding additive to prepare strip-shaped industrial MnCeOx denitrification catalysts. The obtained catalyst exhibits excellent ultra-low temperature denitrification efficiency (150 °C, 100
Hydrogen production via ammonia borane (AB) methanolysis is a promising strategy for H₂ supply. However, it requires high-performance catalysts that are low-cost and highly stable to efficiently catalyze the hydrogen generation reaction. Herein, we report a novel NiO–Cu3Mo2O9 hierarchical nanocatalyst synthesized via a one-pot hydrothermal–calcination method for catalyzing hydrogen production through AB methanolysis. Systematic characterizations, including XRD, SEM, TEM, XPS, and BET analyses, were conducted to confirm the successful synthesis of NiO–Cu3Mo2O9. The catalyst exhibited a low activation energy (Ea = 18.9 kJ·mol⁻¹), excellent stability (H₂ production rate = 170 mL H2·min⁻¹; retaining > 90
A Co3O4/CeO2/Al2O3 ternary oxide catalyst was synthesized via coprecipitation and applied to the one-pot transesterification of glycerol (GL) with dimethyl carbonate (DMC) to produce glycidol (GD). The Al2O3 support enhanced reactant adsorption and increased the density of surface acidic and basic sites, improving catalyst stability and activity. The Co: Ce: Al (1:1:2) catalyst afforded 99.9
The harnessing and utilisation of mechanical energy via frictional routes has emerged as a promising path for advancing clean energy initiatives. Recent research has revealed that a number of nanomaterials have the appealing ability to use mechanical energy through a tribocatalytic mechanism to decompose organic pollutants. Here, we have effectively degraded organic dye using the tribocatalytic degradation under regular magnetic stirring by using SrO doped bioactive glass ceramic. The bioactive glass ceramic prepared by hydrothermal method doped with different concentration of SrO. The materials have been characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), UV-Visible spectroscopy and in vitro bioactivity tested in Hank’s balanced salt solution at 37 °C for 7 days. The formation of hydroxyapatite layer has been confirmed by the XRD, SEM and EDS. SrO-5 sample shows the highest degradation of methylene blue dye which is 97.14
Selective catalytic oxidation of ammonia (NH3-SCO) is an efficient technology for removing unburned NH3 from exhaust gases. Nonetheless, the synthesis method of the support significantly influences NH3-SCO catalyst performance. Herein, CeZrOx mixed oxides were chosen as supports and they were prepared via two different methods: sol–gel and co-precipitation. Subsequently, Ir element as active species was loaded over CeZrOx supports through impregnation method. The effect of support preparation method on NH3-SCO performance of Ir/CeZrOx catalysts was evaluated. The results demonstrated that, Ir/CeZrOx-R catalyst possessed excellent low-temperature activity, which could achieve 100
A series of poly (1-hexyl-3-vinylimidazolium bromide) (P[HVIM]Br)/polymeric carbon nitride (PCN) composites were synthesized via in-situ radical copolymerization of ionic liquid monomer with divinylbenzene (DVB) in the presence of PCN. The swelling behavior of crosslinked poly(ionic liquid)s (PILs) was systematically investigated, and PILs-0.8 (with 0.8 mol
The advancement of fuel cell technologies depends on the design of durable and efficient noble-metal-free electrocatalysts for the oxygen reduction reaction (ORR). In this work, Co-N active sites are successfully engineered onto carbon nano onions (CoNCNO), synthesised via flame pyrolysis of olive oil. The concentric graphitic layered structure of the catalyst is confirmed by HR-TEM images, and the mesoporous texture is evidenced by the nitrogen adsorption-desorption isotherms. The electrochemical evaluation of the catalyst in the alkaline medium gives a limiting current density of – 4.62 mA cm− 2, which is on par with the current density recorded for commercial Pt/C. CoNCNO exhibits a favourable onset potential (0.91 V vs. RHE) and half-wave potential (0.79 V vs. RHE), along with the calculated electron number of 3.85, supporting its remarkable ORR catalytic activity. Moreover, the catalyst surpasses commercial Pt/C in stability in 0.1 M KOH, retaining 96
Hydrogen energy is widely regarded as a highly promising green alternative to conventional fossil fuels. Molybdenum disulfide (MoS2) has been identified as a low-cost catalyst for photocatalytic hydrogen evolution; however, its practical application remains constrained by inherent drawbacks, including basal-plane inertness, poor electrical conductivity, and severe photogenerated carrier recombination. In this work, a series of flower-like MoS2/CoP S‑scheme heterojunctions with varying molar ratios were synthesized via a hydrothermal method followed by a high‑temperature phosphorization process. Characterization results reveal that the introduction of CoP effectively refines the microstructural morphology, enhances the specific surface area, and increases the number of active sites. Meanwhile, the built‑in electric field established at the heterojunction interface facilitates efficient charge migration along the S‑scheme pathway, thereby extending the visible‑light response range and suppressing carrier recombination. When the molar ratio of MoS2 to CoP was 1.0, the resulting composite exhibited the optimal photocatalytic hydrogen‑evolution performance, achieving a hydrogen production rate 3.43 times that of pristine MoS2, while its catalytic activity remained stable after cyclic tests. This study demonstrates that constructing S‑scheme heterojunctions between transition‑metal sulfides and phosphides constitutes an effective strategy for modifying MoS2‑based photocatalysts. Furthermore, it provides a viable reference for the development of low‑cost, high‑performance noble‑metal‑free photocatalysts for sacrificial‑agent‑assisted photocatalytic hydrogen production.
In this study, a porous carbon support (CuCN) with a high specific surface area and an N-doped Cu-N-C network was synthesized by pyrolyzing copper acetylacetonate on a metal-organic framework (ZIF-8) at 900 °C. To investigate the relationship between the preparation process and performance of CuCN-supported palladium nanoparticles, a light-induced synthesis method was employed to replace the traditional high-temperature thermal reduction process, enabling the controlled loading of palladium nanoparticles onto CuCN. A Cu- and N-co-doped carbon-supported palladium nanocatalyst (Pd/CuCN-M) was prepared, and the effects of optimal illumination conditions and reducer types on the catalyst were explored. The results show that the Cu- and N-co-doped carbon-supported palladium nanocatalyst, designated Pd/CuCN-M1, prepared using methanol as the reducing agent and irradiated with near-ultraviolet light at 395 nm, exhibits high catalytic activity and stability. The rate constant for the reduction of p-nitrophenol (4-NP) reached 2.1 min⁻¹, and the conversion rate remained at 90.2
In this study, calcium oxide nanoparticles (CaO-NPs) were synthesized via the modified Pechini sol-gel method using citric acid as the chelating agent and ethylene glycol as the polycondensation medium, and evaluated for the heterogeneous catalysis of soybean waste cooking oil (SWCO) transesterification. The synthesized catalyst was characterized by X-ray diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Brunauer–Emmett–Teller and Barrett–Joyner–Halenda (BET-BJH), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), Hammett indicator analysis, and benzoic acid titration, confirming the formation of mesoporous CaO-NPs with an estimated crystallite size of 47.4 nm and a BET surface area of 16.0 m2 g− 1. Process optimization was performed using response surface methodology (RSM) via a central composite design (CCD), yielding a fatty acid methyl ester (FAME) yield of 97.40
An ionic liquid-grafted catalyst, denoted as IL@MIL-101-NH2, was synthesized by introducing a novel functionalized bis-imidazolium ionic liquid containing carboxyl groups into the MIL-101-NH2(Cr) using a simple one-step method. The structural features of the catalyst were characterized by FT-IR, XRD, XPS, BET, SEM and so on, and its catalytic performance in the cycloaddition reaction of carbon dioxide (CO2) with propylene oxide (PO) to propylene carbonate (PC) was investigated. The results demonstrated that IL@MIL-101-NH2 exhibited excellent catalytic activity. Under the conditions of 110 °C, 2 MPa, 3 h, and a catalyst loading of 3.0 wt
In this work, ZnO films synthesized with traces of Cu by the sol gel method and deposited on ITO (Indium Tin Oxide) substrate showed potential application in photoelectrochemical and photocatalytic systems. The films are characterized by different techniques like X-ray diffraction (XRD), Electronic microscopy (SEM), UV-Vis Spectrophotometry, and Photoluminescence (PL), evidenced the synthesis of the material, as well as improvement in properties such as light absorption, low recombination, and morphology. Photoelectrochemical tests of ZnO/Cu films showed an improvement in charge transfer with respect to ZnO under UV light irradiation due to the increment of donor density. On the other hand, Nyquist curves showed that the addition of Cu decreases the resistance to charge transfer provoking an improvement in the conductivity of the films. Finally, the hydrogen photocatalytic tests showed an increase in the ZnO/Cu films with respect to ZnO.
Developing efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) remains a key challenge for sustainable hydrogen production. In particular, achieving an optimal balance between hydrogen adsorption and desorption in single-cluster catalysts(SCC) is still unresolved. Herein, density functional theory (DFT) calculations were performed to investigate Ru3 and Ru2Fe clusters anchored on single-vacancy graphene (SVG) as HER catalysts. The results reveal that the binding energy of the Fe-doped Ru cluster is more negative (− 5.88 eV) than that of the pure Ru3 cluster (− 5.56 eV). The Ru–Ru bond length expands from 2.30 Å in the gas phase to 2.36 Å when supported on SVG for the pure Ru3 cluster, and from 2.36 Å in the gas phase to 2.45 Å for Fe-doped Ru2Fe. Meanwhile, the Ru–Fe bond length increases from 2.15 Å in the gas phase to 2.193 Å on SVG. These bond length variations, combined with the highly negative binding energy, induce an upward shift in the Ru d-band center from − 1.58 eV(Ru3) to − 1.478 eV(Ru2Fe), promoting stronger hydrogen adsorption. Ru3 @SVG exhibits near-thermoneutral H adsorption (− 0.165 eV), indicating optimal HER activity, while Ru2Fe @SVG displays over binding (− 0.341 eV), especially at Ru top sites. A linear correlation exists between the d-band center and H adsorption strength. Mechanistic analysis shows that the highly negative binding energy, bond length variations, and d-band shift enhance cluster stability through synergistic electronic and structural effects, making Fe-doped Ru2Fe@SVG the most favorable, durable, and promising candidate for experimental synthesis. In contrast, Ru3 @SVG follows a balanced HER pathway, while Ru2Fe@SVG is hindered by slow H desorption. These findings place SVG-supported clusters as favorable, durable HER catalysts, highlighting electronic structure tuning for Pt-alternative design.
(R)-( +)-1-Boc-3-aminopyrrolidine is an indispensable chiral intermediate for central nervous system drugs and Janus kinase inhibitors, yet its traditional chemical synthesis is plagued by harsh conditions, heavy pollution, and inadequate stereocontrol. Biocatalysis with transaminases (TAs) offers an attractive green alternative, but discovering optimal enzymes remains a major bottleneck. Here, we report a synergistic integration of machine learning (ML) with experimental validation to break this bottleneck. By ML-enabled evaluation of seven phylogenetically diverse TAs, we rapidly identified TA-6 from Arthrobacter sp. as an outstanding (R)-selective biocatalyst for the asymmetric amination of prochiral N-Boc-3-pyrrolidinone. Notably, using a whole-cell catalyst loading of only 10 g/L (DCW), TA-6 converted 100 g/L of ketone substrate on a 20-L preparative scale, delivering the desired (R)-enantiomer in 99.5
In this study, three industrial TiCl 4 /MgCl 2 -based Ziegler–Natta catalysts were investigated to clarify how their physicochemical characteristics influence polymerization behavior and the resulting polyethylene properties. Catalyst composition, porosity, and particle morphology were evaluated using standard characterization techniques. Ethylene polymerization was performed under two experimental modes: first, with equal catalyst loading to compare intrinsic catalytic performance; and second, with adjusted catalyst amounts to produce polyethylene samples of similar yield for a more reliable comparison of polymer properties. Polymer characteristics, including melt flow index (MFI), flow rate ratio (FRR), differential scanning calorimetry (DSC), density, and particle size distribution, were assessed to investigate hydrogen response, comonomer response, and polymer morphology. Additionally, propylene pre-polymerization was carried out to study its influence on catalyst behavior and to simulate industrial pre-polymerization practices. Overall, this work establishes clear correlations between catalyst structure, polymerization kinetics, and polyethylene properties and highlights the potential of pre-polymerization as a strategy to tune the performance of industrial Ziegler–Natta catalysts.
Orange peel extract served as the biomass component during calcination of the cerium precursor to prepare OP-CeO2-Nps. SEM images distinguished the two materials morphologically: CeO2-Nps were composed mainly of spherical particles, whereas OP-CeO2-Nps showed an uneven porous powder form. X-ray diffraction and Raman analysis verified that the cubic fluorite phase remained in the nanoparticles, and the Ce–O vibration was supported by FT-IR and Raman signals. XPS further clarified the chemical states of C(1s), O(1s), and Ce(3d). UV-Vis diffuse reflectance placed the OP-CeO2-Nps energy positions at -0.50 to 2.64 eV and those of CeO2-Nps at -0.395 to 2.535 eV. Ciprofloxacin (CIP) served as the antibiotic model compound for photocatalytic evaluation. Under UV irradiation, OP-CeO2-Nps achieved better degradation than CeO2-Nps, with efficiency varying with pH, catalyst amount, and initial CIP level. Scavenging experiments identified the main reactive roles of h+, ⋅OH, and ⋅O–2 during CIP decomposition. Taken together, OP-CeO2-Nps is a promising photocatalyst for antibiotic-like wastewater, and it also generated obvious inhibition zones against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis.
A series of NiFex/CeO2 bimetallic catalysts was prepared by the incipient wetness impregnation method and subsequently applied for CO2 methanation. The CO2 methanation activity of the NiFex/CeO2 catalyst is significantly enhanced by the introduction of an appropriate amount of Fe. At 280 °C, 100 kPa and 24,000 mL/(g·h), the NiFe0.3/CeO2 catalyst exhibits a CO2 conversion of 88.6 High CO2 methanation activity was achieved over NiFex/CeO2 bimetallic catalyst, in which a strong electronic interaction exists between Fe and Ni.
