Catalyst For Synthesis Research Articles

Metal-organic frameworks-derived CaO/ZnO composites as stable catalysts for biodiesel production from soybean oil at room temperature

Biodiesel presents a sustainable alternative to fossil fuels, yet traditional homogeneous catalysts like sodium and potassium hydroxide face challenges with separation and reuse. Calcium oxide (CaO) is an effective heterogeneous catalyst for biodiesel production, but its chemical instability under reaction conditions restricts its long-term performance. This study introduces MOF-mediated synthesis (MOFMS) of heterogeneous catalysts, specifically CaO@ZnO and ZnO@CaO nanocomposites, from inexpensive and non-toxic metal salts and linkers in water. Comprehensive characterization techniques, including XRD, FT-IR, BET, FE-SEM, ICP, and CO2-TPD, were employed to analyze these catalysts. When applied to biodiesel production from soybean oil at ambient temperature and pressure, CaO@ZnO and ZnO@CaO achieved impressive biodiesel conversion rates of 99% and 92%, respectively, within 25 min. Both catalysts maintained their activity over six utilization cycles, with Ca²⁺ leaching remaining below 4% (2% for CaO@ZnO and 4% for ZnO@CaO) after the sixth run. These results provide valuable insights into catalyst preparation and leaching control, enhancing reusability in biodiesel production. Future research should aim to improve the long-term stability and reusability of these catalysts, investigate their performance with various feedstocks, and evaluate the feasibility for industrial applications.

Nickel Nanoparticles Stabilized on B and N-Doped Graphitic Carbon as an Excellent Catalyst for One-Pot Synthesis of Industrially Important Flavoring Ketones

Nickel Nanoparticles Stabilized on B and N-Doped Graphitic Carbon as an Excellent Catalyst for One-Pot Synthesis of Industrially Important Flavoring Ketones

Fe3O4@HA-Cu(OAc)2 nanocomposite as a nanomagnetic water-compatible catalyst for efficient synthesis of 1,2,3-triazoles in water

A new humic acid-based nanomagnetic copper(II) composite was prepared and used as an eco-friendly recoverable catalyst for synthesizing 1,4-disubstituted 1,2,3-triazoles. The synthesis was done via the three-component click reaction of alkyl halide, sodium azide, and terminal alkyne with good to excellent yield. A simple magnetic copper acetate composite, Fe3O4@HA-Cu(OAc)2, was prepared using humic acid and characterized by SEM, TEM, XRD, EDX, EDS-mapping, VSM, TGA, AAS, and FT-IR. The catalyst showed high catalytic potential in a one-pot three-component click reaction in the synthesis of 1,2,3-triazoles. The nanomagnetic Fe3O4@HA-Cu(OAc)2 catalyst demonstrated high efficiency, stability, compatibility with oxygen/water and recyclable copper(II), with cost-effectiveness. The catalyst was easily recovered with an external magnetic field, and therefore, time and energy were saved as no filtration or decantation technique was needed. Due to the high dispersibility in water, nanomagnetic Fe3O4@HA-Cu(OAc)2 was utilized as a highly efficient catalyst for the click synthesis of triazoles.

Acid-decorated chitosan-magnetic aluminum ferrite as a bionanocomposite catalyst for green synthesis of biologically active [4,3‑d]pyrido[1,2‑a]pyrimidin-6‑ones

In this study, a novel hybrid nanostructure consisting of acid-decorated chitosan and magnetic AlFeO3 nanoparticles was fabricated. The acid-decorated chitosan provided a stable and biocompatible matrix for the magnetic AlFeO3 nanoparticles. Various techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction patterns (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), specific surface area (BET), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to characterize and confirm the successful synthesis of the hybrid nanostructure. The newly prepared magnetic bio-nanocomposite (AlFeO3@CS-SO3H) was effectively employed in the synthesis of biologically active 7-aryl[4,3d]pyrido[1,2a]pyrimidin-6(7H)one derivatives in an aqueous medium, creating an environmentally friendly process. The desired products were manufactured in high yields (88–98%) without the formation of noticeable side products. This procedure offers numerous advantages, including short reaction times, the use of a green solvent, the ability to reuse the catalyst without a significant decrease in catalytic activity, and easy separation of the catalyst using an external magnet. The high yields and minimal side product formation indicate the efficiency and selectivity of this method, making it a promising strategy for the sustainable production of biologically active compounds.

Deep eutectic solvents in analysis, delivery and chemistry of pharmaceuticals.

Deep eutectic solvents (DES) have an emerging scientific role, assisting modern pharmaceutics. They are uniquely supporting the resolution of crucial issues, such as the effective extraction and isolation of bio-actives. They act as media and catalysts for pharmaceutical drug synthesis, and as green solvents and modifiers in pharmaceutical analysis. Their role in pharmaceutical formulation and drug delivery is also up-and-coming, for instance, as alternative drug-solubilizing agents, drug stabilizers and functional additives, as therapeutic deep eutectic solvents, deep eutectic API, and monomers and reaction media for the synthesis of biomaterials for advanced drug delivery. The DES also help transforming medicinal/pharmaceutical chemistry. Although DES were described in 1918, their first pharmaceutical use is only reported in 1960. In view of their broad applicability in pharmaceutics, it may be interesting to review their history, origin, evolution, potential advantages, limitations, and specific applications as green solvents. A chronological and comparative study of the literature showed the important role of DES in green approaches for modern pharmaceuticals. The concepts, applications, and outcomes of DES in pharmaceutical analysis, formulation/drug delivery, and pharmaceutical/medicinal chemistry are presented. A comprehensive outline of the atypical applications of DES as effective green solvents in pharmaceutical bioactive extraction was assessed. Efforts to present classifications of DES explored in pharmaceuticals were also made. The present manuscript also covers computational trend, adds on commercial aspects with potential future applications of DES in pharmaceutical sciences.

Coptis Root-Derived Hierarchical Carbon-Supported Ag Nanoparticles for Efficient and Recyclable Alkyne Halogenation

The advancement of green chemistry and sustainable chemical processes has been significantly facilitated by catalytic systems derived from plant roots, which also present substantial application prospects in the realm of chemical synthesis. This study utilized the roots of Rhizoma Coptidis as a support to successfully fabricate a silver-based nanocatalyst. By depositing silver nanoparticles onto the root material of Coptis chinensis and subjecting it to carbonization, a silver/carbon composite was synthesized, featuring monodisperse silver nanoparticles and a hierarchical mesoporous carbon framework. This composite exhibits robust surface activity, a well-defined pore structure, and superior mechanical properties. The catalyst achieves a catalytic yield nearing 90%, showcasing remarkable activity in terminal alkyne halogenation reactions. Its stability and recyclability are markedly enhanced; it retains 95% of its mass and remains unaltered in the reaction solvent for over 160 h after five cycles. This method simplifies the synthesis of terminal alkynes and their derivatives, rendering the process more environmentally benign and efficacious. Furthermore, it broadens the potential applications of Rhizoma Coptidis in synthetic chemistry and pioneers a novel approach for the synthesis of precious metal catalysts from renewable resources.

Highly loaded copper on mesoporous silica as catalysts for acetaldehyde production from ethanol: their synthesis, characteristics, and catalytic properties

AbstractBACKGROUNDThe present study investigates copper (Cu)/mesoporous catalysts supported on mesocellular foam silica (MCF‐Si) and Santa Barbara Amorphous‐15 (SBA‐15) for ethanol dehydrogenation, focusing on catalyst synthesis, performance, and stability. Cu catalysts were impregnated on the MCF‐Si and SBA‐15 supports with different pore morphologies – spherical and hexagonal structure, respectively – using the wetness impregnation method and incipient wetness impregnation (IW), with a Cu loading of 60 wt%. The synthesized catalysts underwent physical and chemical characterization via scanning electron microscopy combined with energy‐dispersive X‐ray spectroscopy, X‐ray fluorescence, X‐ray diffraction (XRD), transmission electron microscopy, N2 physisorption, X‐ray photoelectron spectroscopy, thermogravimetric analysis (TGA), carbon monoxide chemisorption, hydrogen temperature‐programmed reduction (H2 TPR), ammonia temperature‐programmed desorption, and carbon dioxide temperature‐programmed desorption.RESULTSIt was observed that copper impregnation of the support in either method did not alter the structural characteristics. Incipient wetness resulted in superior catalytic activity, particularly with Cu/MCF‐Si (IW), having pure ethanol conversion of 99.4% and acetaldehyde yield of 95.7%, attributed to effective Cu dispersion and a lower reduction temperature. Further investigation of time‐on‐stream (TOS) behavior revealed sustained ethanol conversion rates exceeding 95% with a 10% ethanol feed. However, catalyst deactivation due to coke formation occurred with 100% ethanol, highlighting the importance of understanding catalyst stability and deactivation mechanisms.CONCLUSIONIncipient wetness resulted in superior performance compared to wetness impregnation, with Cu/MCF‐Si (IW) achieving exceptional ethanol conversion rates due to effective Cu dispersion and a lower reduction temperature. TOS testing revealed sustained ethanol conversion; however, catalyst deactivation was observed with pure ethanol feed due to carbon deposition (coke formation). Characterization techniques, including XRD, TGA, and H2 TPR analyses, provided valuable insights into the deactivation processes, highlighting the need for strategies to mitigate oxidation‐induced deactivation. © 2025 Society of Chemical Industry (SCI).

Confined growth by self-combustion of a Cu-based nanophase into mesostructured acid supports for DME production from CO2.

This work deals with the design of nanocomposite hydrogenation-dehydration bifunctional catalysts for the one-pot conversion of CO2 to dimethyl ether (DME), focusing on obtaining a high and homogeneous dispersion of a Cu-based CO2 hydrogenation phase into the pores of mesostructured supports. Particularly, three aluminosilicate mesostructured acid catalysts with catalytic activity towards methanol dehydration and featuring different porous structures (Al-MCM-41, Al-SBA-15, Al-SBA-16) were synthesized and used as supports to host a CuO/ZnO/ZrO2 (CZZ) CO2 hydrogenation catalyst for methanol synthesis. The use of a mesostructured support allows to maximize the exposed surface of the CO2 reduction function by nanostructuring it through its confinement within the mesochannels, thus obtaining nanocomposite bifunctional catalysts with an ultra-small hydrogenation nanophase. The nanocomposites were obtained using an impregnation strategy combined with a self-combustion reaction, allowing to incorporate the CO2 reduction phase inside the mesopores. In all cases, the characterization shows that the hydrogenation phase species are highly and homogeneously dispersed into the supports as either small nanoparticles or as a nanolayer. The as-obtained nanocomposites were tested for their catalytic activity and the results discussed taking into account the structural, textural, and acidic properties of the supports and nanocomposites.

Synthesis and Catalytic Application of Cu2O Nano Hollow Arrays in RingExpansion Aromatization Reactions

Introduction: Aromatization of dithioacetal derivatives is essential for the synthesis of bioactive compounds and drug design, playing a key role in pharmaceuticals, agrochemicals, and materials science. This study explores the synthesis and catalytic application of Cu2O nano hollow arrays in ring-expansion aromatization reactions of cyclic dithioacetal derivatives obtained from cyclohexanones. Methods: By using Cu2O nano hollow arrays prepared through molecular templates and a simple hydrothermal process, the electrophilicity of N-bromosaccharin was enhanced, allowing for efficient and selective production of aromatic compounds with yields ranging from 63-96%. Copper acetate is transformed into Cu2O nano hollow arrays in aqueous media, with polyvinylpyrrolidone acting as a capping agent and (+)-L-tartaric acid as a structure-directing surfactant and multidentate ligand. Results: The synthesized Cu2O nano hollow arrays were characterized using transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy-dispersive Xray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to verify their morphology, structure, and composition. Conclusion: This method not only offers a cost-effective and environmentally friendly approach to synthesizing Cu2O with unique nano hollow structures, but also demonstrates their efficacy as catalysts in organic synthesis, particularly in the rarely reported ring-expansion aromatization of cyclic dithioacetal derivatives of cyclohexanone, emphasizing their broader applicability in materials science and catalysis.

Structural Characterization of the Platinum Nanoparticle Hydrogen-Evolving Catalyst Assembled on Photosystem I by Light-Driven Chemistry.

Directed assembly of abiotic catalysts onto biological redox protein frameworks is of interest as an approach for the synthesis of biohybrid catalysts that combine features of both synthetic and biological materials. In this report, we provide a multiscale characterization of the platinum nanoparticle (NP) hydrogen-evolving catalysts that are assembled by light-driven reductive precipitation of platinum from an aqueous salt solution onto the photosystem I protein (PSI), isolated from cyanobacteria as trimeric PSI. The resulting PSI-NP assemblies were analyzed using a combination of X-ray energy-dispersive spectroscopy (XEDS), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), small-angle X-ray scattering (SAXS), and high-energy X-ray scattering with atomic pair distribution function (PDF) analyses. The results show that the PSI-supported NPs are approximately 1.8 nm diameter disk-shaped particles that assemble at discrete sites with 145 Å separation. This separation is too large to be consistent with NP nucleation and growth at a site adjacent to the FB cofactor site. Instead, we suggest a mechanism for NP growth at hydrophobic sites on the PSI stromal surface. The NPs photoreductively assembled on the PSI stromal surface are found to be analogous to the nanostructures produced by successive cycles of atomic layer deposition (ALD) of platinum onto 40 nm porous anodic alumina oxide supports, although the mechanisms for nucleation appear to differ. This work establishes a foundation for the investigation of the reductive assembly of abiotic metal catalysts at sites connected to photochemically reducing equivalent production in PSI.

Synthesis and characterization of zirconium oxide-based catalysts for the oxygen reduction reaction via the heat treatment of zirconium polyacrylate in an ammonia atmosphere

Synthesis and characterization of zirconium oxide-based catalysts for the oxygen reduction reaction via the heat treatment of zirconium polyacrylate in an ammonia atmosphere

Critical review on development of methylene blue degradation by wet catalytic methods

Abstract The development of textile, agriculture, and other related industries has increased the risk of excessive methylene blue (MB) emissions, making efficient treatment of MB an urgent issue in terms of the economy and environment. The most commonly used chemical treatment methods were wet catalytic methods, including catalytic wet air oxidation (CWAO), catalytic wet peroxide oxidation (CWPO), and photocatalysis. CWAO and CWPO both show fast reaction rates and are environmentally friendly. CWAO uses air as an oxidant at a relatively low cost and can effectively solve the leaching problem of the catalyst. CWPO employs inorganic peroxides like hydrogen peroxide (H2O2) as oxidants to form radicals, showing high efficiency. Photocatalytic degradation utilizes light energy to transform pollutants into harmless molecules with fast kinetic. The selection and application of different methods are analyzed basing on the balance among cost, scale, and efficiency. Finally, the perspective of the effective removal of MB is summarized, containing multiple method combinations, catalyst synthesis optimization, and practical application with less side reaction and instrument loss. More promising technology should be considered in the future for better degradation of MB in the industrial field.

Automatic monitoring and on-line chiral separation of chiral drug synthesis.

Chiral synthesis of single chiral drugs offers high efficiency, controllable costs, and excellent enantioselectivity, making it crucial in the pharmaceutical industry. A significant number of studies on chiral drug synthesis primarily focuses on the design and synthesis of innovative chiral catalysts and ligands with extremely high selectivity, as well as the development of new methods and strategies. Nonetheless, the on-line monitoring of chiral drug synthesis and its underlying mechanisms remain obscure. The principal challenge lies in the diverse synthesis pathways and intricate mechanisms of chiral drugs, with numerous intermediates and by-products. To tackle this issue, employing the chiral drug omeprazole as a breakthrough, we design and establish a reliable and stable analytical method to monitor the synthesis process. By integrating electrokinetic chromatography technology with automatic sequence injection, the chiral synthesis of omeprazole can be comprehensively tracked and monitored throughout its entire process. During the chiral drug synthesis process, all compounds, containing all reagents and products (omeprazole sulfide, R-omeprazole, S-omeprazole, iodobenzene and iodobenzene diacetate) are efficiently separated and simultaneously detected through a single run. The method shows a high resolution greater than 1.2, a wide linear range with a detection limit as low as 0.008 μM, as well as exceptional repeatability in sequence analysis. Therefore, the proposed method has demonstrated significant value in the analysis of chiral drug synthesis and holds potential for extensive application in the industrial production of chiral compound synthesis.

Electrochemical Ammonia Synthesis at p-Block Active Sites Using Various Nitrogen Sources: Theoretical Insights.

Electrochemical nitrogen conversion for ammonia (NH3) synthesis, driven by renewable electricity, offers a sustainable alternative to the traditional Haber-Bosch process. However, this conversion process remains limited by a low Faradaic efficiency (FE) and NH3 yield. Although transition metals have been widely studied as catalysts for NH3 synthesis through effective electron donation/back-donation mechanisms, there are challenges in electrochemical environments, including competitive hydrogen evolution reaction (HER) and catalyst stability issues. In contrast, p-block elements show unique advantages in light of higher selectivity for nitrogen activation and chemical stability. The present article explores the potential of p-block element-based catalysts as active sites for NH3 synthesis, discussing their activation mechanisms, performance modulation strategies, and future research directions from a theoretical perspective.

Selectivity control by zeolites during methanol-mediated CO2 hydrogenation processes.

The thermocatalytic conversion of CO2 with green or blue hydrogen into valuable energy and commodity chemicals such as alcohols, olefins, and aromatics emerges as one of the most promising strategies for mitigating global warming concerns in the future. This process can follow either a CO2-modified Fischer-Tropsch synthesis route or a methanol-mediated route, with the latter being favored for its high product selectivity beyond the Anderson-Schulz-Flory distribution. Despite the progress of the CO2-led methanol-mediated route over bifunctional metal/zeolite catalysts, challenges persist in developing catalysts with both high activity and selectivity due to the complexity of CO2 hydrogenation reaction networks and the difficulty in controlling C-O bond activation and C-C bond coupling on multiple active sites within zeolites. Moreover, the different construction and proximity modes of bifunctionality involving redox-based metallic sites and acidic zeolite sites have been explored, which have not been systematically reviewed to derive reliable structure-reactivity relationships. To bridge this "knowledge gap", in this review, we will provide a comprehensive and critical overview of contemporary research on zeolite-confined metal catalysts for alcohol synthesis and zeolite-based bifunctional tandem/cascade catalytic systems for C2+ hydrocarbons synthesis in CO2 hydrogenation via the methanol-mediated route. Accordingly, special emphasis will be placed on evaluating how confinement and proximity effects within the "redox-acid" bifunctional systems influence the reaction outcomes, particularly regarding product selectivity, which has also been analyzed from the mechanistic standpoint. This review will also examine the synergistic interactions among various catalyst components that govern catalysis, offering valuable insights for the rational design of new or improved catalyst systems. By discussing current challenges and recognizing future opportunities in CO2 hydrogenation using zeolite-based bifunctional catalysis, this review aims to contribute to the advancement of sustainable and efficient processes for CO2 valorization.

Dielectrically Monitored Flow Synthesis of Functional Vaccine Adjuvant Mixtures via Microwave-Assisted Catalytic Chain Transfer Processing

A novel flow process to produce low-molecular-weight (Mwt) methacrylate oligomer mixtures that have potential as vaccine adjuvants and chain transfer agents (CTAs) is reported. The chemistry and process were designed to significantly reduce the number of stages required to manufacture methyl methacrylate oligomer-in-monomer mixtures with an oligomer Mwt range of dimers to pentamers and >50% conversion. Combining rapid in-flow, in situ catalytic chain transfer polymerization catalyst synthesis and volumetric microwave heating of the reaction medium resulted in catalyst flow synthesis being completed in <4 min, removing the need to pre-synthesize it. The steady-state operation was then successfully maintained with very low levels of external energy, as the process utilized the reaction exotherm. The microwave process outperformed a comparative conventionally heated system by delivering a 20% increase in process throughput with no change in final product quality or conversion. Additionally, combining flow and in situ catalyst processing enabled the use of a more oxidatively unstable catalyst. This allowed for in situ catalyst deactivation post-generation of the oligomers, such that residual catalyst did not need to be removed prior to preparing subsequent vaccine adjuvant or CTA screening formulations. Finally, dielectric property measurements were able to monitor the onset of reaction and steady-state operation.

An unusual chiral-at-metal mechanism for BINOL-metal asymmetric catalysis

Chiral binaphthols (BINOL)-metal combinations serve as powerful catalysts in asymmetric synthesis. Their chiral induction mode, however, typically relies on multifarious non-covalent interactions between the substrate and the BINOL ligand. In this work, we demonstrate that the chiral-at-metal stereoinduction mode could serve as an alternative mechanism for BINOL-metal catalysis, based on mechanistic studies of BINOL-aluminum-catalyzed asymmetric hydroboration of heteroaryl ketones. Theoretical calculations reveal that an octahedral stereogenic-at-metal aluminum alkoxide species is the most stable species within the reaction system, and also is the catalytic relevant intermediate, promoting the stereo-determining hydroboration reaction through a ligand-assisted hydride transfer mechanism rather than the conventional hydroalumination mechanism. These computations reproduce the experimental selectivities and also rationalize the stereoinduction mechanism, which arises from the aluminum-centered chirality induced by chiral BINOL ligands during diastereoselective assembly. The reliability of the proposed mechanism could be verified by the single-crystal X-ray diffraction characterization of the octahedral aluminum alkoxide complex. Additional NMR and Electronic Circular Dichroism (ECD) experiments elucidated the behavior of the hexacoordinated aluminum alkoxide in the solution phase. We anticipate that these findings will extend the applicability of BINOL-metal catalysis to a broader range of reactions.

Zirconia sulfate supported on graphitic carbon nitride nanoplates: a new catalyst for efficient synthesis of 5-hydroxymethylfurfural

Zirconia sulfate supported on graphitic carbon nitride nanoplates: a new catalyst for efficient synthesis of 5-hydroxymethylfurfural

Dry-Solid-Electrochemical Synthesis: A General Method for Large Scale Synthesis of Single-Atom Catalysts with High Metal loadings.

Single-atom catalysts (SACs) with high metal loadings are highly desirable but still challenging for large scale synthesis. Here we report a new technique named as dry-solid-electrochemical synthesis (DSES) for a general large-scale synthesis of SACs with high metal loadings in an energy-conservation and environment-friendly way. With it, a series of pure carbon-supported metal SACs (Platinum up to 35.0 wt%, Iridium 21.2 wt%, Ruthenium 20.4 wt% and Iron 17.6 wt%) with high metal loadings were obtained. Particularly, a Pt SAC with Pt 23.9 wt% and remarkable oxygen reduction reaction (ORR) performance in fuel cells is synthesized on kilogram scale. Based on multiple control experiments, a unique redox mechanism for DSES process is proposed: metal precursors on conductive supports are reduced to metals via a homolytic cleavage of metal-halogen bonds by the attacking of electrons flowing through the dry solid phase. Such versatile technique paves a new economical and environment-friendly pathway for fabricating high-metal-loading SACs or atomic dispersion catalysts.

Ru/Beta Zeolite Catalysts for Levulinic Acid Hydrogenation: The Importance of Catalyst Synthesis Methodology

Ru/Beta Zeolite Catalysts for Levulinic Acid Hydrogenation: The Importance of Catalyst Synthesis Methodology