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A CuI@UiO-67-bpy (MOF II) catalyst was successfully synthesized by immobilizing a small amount of CuI onto the zirconium-based MOF (UiO-67-bpy, MOF I). Copper-doped CuI@UiO-67-bpy has an isostructural nature with the parent UiO-67 framework and a large surface area of approximately 1285 m2 g−1. Moreover, the material was thoroughly characterized using SEM, PXRD, TGA, FTIR, and XPS methods. The as-synthesized CuI@UiO-67-bpy catalyst can be an efficient heterogeneous catalyst for promoting C–H arylation of 1,3,4-oxadiazoles with aryl iodides and benzoxazoles or benzothiazoles with diaryliodonium salts. Furthermore, the catalyst was recoverable and reusable, maintaining a high catalytic activity even after three cycles. The combination of the advantages of both homogeneous molecular CuI catalysts and solid MOF structures in this system may bring new opportunities for the development of highly active heterogeneous copper catalysts for a variety of Cu-catalyzed transformations. [ABSTRACT FROM AUTHOR]

Heterogeneous acid catalysis provides a sustainable and cost-effective replacement to homogeneous catalysts, as it is easily accessible and reusable. In this research, biodiesel was synthesized from palm fatty acid distillate (PFAD) by way of esterification utilizing a heterogeneous acid catalyst composed of CuO/WPLAHC-S, which was derived from waste palm leaves-based hydrochar. The catalyst was characterized using TGA, XRD, FESEM, EDX, BET, FT-IR, Raman, and acid density. The synthesized catalyst was found to have remarkable stability during the thermal test. The BET surface area, pore volume, and pore width of the synthesized catalyst were measured at 118.47 m2/g, 0.05 cm3/g, and 8.15 nm, respectively. The significant acidity density (18.57 mmol/g) facilitated the simultaneous esterification process. The investigation found that the copper-doped activated hydrochar, treated with sulfuric acid, exhibited excellent catalytic activity. A high yield of 98.34% fatty acid methyl ester (FAME) was achieved under mild conditions with the use of a catalyst concentration of 2 wt.%, a methanol-to-PFAD molar ratio of 15:1, and a reaction temperature of 80 °C for a duration of 3 h. For statistical analysis, one-way ANOVA was applied to verify the experimental data set for PFAD esterification optimization parameters by predetermining a 95% confidence interval. All of the esterification parameters met the expectation of a p-value less than 0.05 indicating its significant impact on FAME production. The catalyst exhibited excellent performance by maintaining a FAME yield of over 90% after four reaction cycles without requiring reactivation. The study demonstrates the efficacy of CuO/WPLAHC-S as a promising acid catalyst derived from waste palm leaves-based hydrochar for biodiesel production from PFAD. [ABSTRACT FROM AUTHOR]

One‐pot synthesis of acetamides, benzimidazoles, and benzothiazoles are central reactions for synthesizing pharmaceuticals and fine chemicals. Despite tremendous progress in heterogeneous catalysis, the synthesis of these nitrogen‐containing compounds still remains challenging. Here, we report an efficient, simple, and cost‐effective nitrogen‐doped CeO2‐supported Co single‐atom catalyst (SAC) (Co/N‐CeO2) enabled synthesis of acetamides, benzimidazoles, and benzothiazoles. As far as we know, this is the first to report that SACs catalyze the synthesis of acetamides, benzimidazoles, and benzothiazoles. Detailed spectroscopic characterization revealed the structure of catalytic center. Harnessing the catalytic activity of SACs, the work offers promising routes for future synthesis of heterocycles. [ABSTRACT FROM AUTHOR]

Inspired by the multienzymatic relay catalysis in nature, herein, we reported a pioneering bio‐inspired Cu/Pd bimetallic composite microspheres (Cu/CMC@Pd/C) as a simple and efficient relay catalyst for the homo‐coupling of arylboronic acids. In this composite, Pd/C was encapsulated by Cu(II)‐crosslinking carboxymethyl cellulose (Cu/CMC). Cu/CMC@Pd/C microspheres were easily achieved by adding a mixture solution of Pd/C and carboxymethyl cellulose into a Cu(II) solution through an ion exchange reaction between carboxylate groups of CMC and Cu(II) ions. The morphology and composition of the as‐prepared Cu/CMC@Pd/C microspheres were well characterized using various analytical tools such as FT‐IR, XRD, XPS, SEM, TEM, elemental mapping, EDS, and ICP‐AES. The analysis indicated that the composite microspheres have a porous structure and Pd/C is uniformly distributed within the interior of the composite microspheres. The porous structure facilitates mass transfer of the substrate and increases the contact area of the catalyst, thus improving reaction efficiency. The performance of Cu/CMC@Pd/C microspheres was assessed in the homo‐coupling of arylboronic acid for the synthesis of symmetric biaryl without the need for an aryl halide as a partner. This process mimics a multienzyme catalysis through a relay Cu(I)‐catalyzed halogenation of one portion of arylboronic acid and a Pd(0)‐catalyzed Suzuki–Miyaura cross‐coupling between the in situ generated aryl halide and another portion of arylboronic acid. The results showed that this bio‐inspired Cu/CMC@Pd/C has excellent relay catalytic activity with tolerance of broad functional groups, producing the desired symmetrical biaryls in excellent yields within a short reaction time under mild conditions. Moreover, the catalyst can be easily recovered through simple filtration and still has good catalytic activity after six cycles. Consequently, this innovative pseudo‐homogeneous Cu/Pd relay catalyst emerges as a convenient and efficient alternative for the synthesis of asymmetric biaryls. [ABSTRACT FROM AUTHOR]

Polyoxometalate-based metal–organic frameworks (POMOFs) are highly effective heterogeneous catalysts that combine the catalytic activity of polyoxometalates (POMs) with the high surface area, tunable porosity, and structural diversity of MOFs. Nevertheless, there is still a lack of a general method to integrate POMs with various transition metal-based building units into POMOFs under mild conditions. In this work, we employed imine bonds to link amino-functionalized Anderson-type POMs with aldehyde-terminated divalent metal clusters, resulting in a series of isostructural POMOFs, M(II)-POMOFs (M = Zn, Co, Mg, or Mn). Furthermore, we used post-synthetic metal exchange and oxidation to transform Zn-POMOF into Fe(III)-POMOF with strong Lewis acidic Fe3+ sites. Notably, both the synthesis and post-synthetic modifications were performed under mild conditions (room temperature, acid-free), preventing the decomposition of the POMs. Compared to M(II)-POMOFs or MOFs without POMs, the combination of Lewis acidic Fe3+ and POMs enhanced its catalytic activity for CO2 cycloaddition with epoxides, enabling efficient synthesis of cyclic carbonates. This versatile synthetic method could broaden the scope of POMOFs, extending their applications in catalysis and beyond. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, a new mesoporous silica nanostructure functionalized with hydrobenzoin substituted cobalt (II) phthalocyanine (MCM‐41‐CoPc) was prepared by grafting first 3‐chloropropyltriethoxysilane (CPTES) and then peripherally hydrobenzoin substituted cobalt (II) phthalocyanine (CoPc) onto mesoporous silica nanomaterial (MCM‐41). The structural properties of heterogeneous catalyst MCM‐41‐CoPc were elucidated by FT‐IR, XRD, TEM, EDS, TGA, solid‐state UV–Vis and N2 sorption analyses. The catalytic performance of MCM‐41‐CoPc was investigated in the oxidation of benzyl alcohol to benzaldehyde. To find the best catalytic conditions for aldehyde selectivity, the effect of the different parameters such as temperature, reaction time, oxidant, solvent, amount of the substrate, and oxidant on the catalytic activity of MCM‐41‐CoPc was investigated in detail. The selective oxidation of benzyl alcohol to benzaldehyde in the presence of MCM‐41‐CoPc was achieved with high aldehyde selectivity (98%) and moderate conversion (57%). The reusability of MCM‐41‐CoPc was tested in three consecutive cycle and no catalytic activity loss was observed. Additionally, it has been determined that the product selectivity can be controlled depending on the type of reaction solvent. When ethyl acetate was used as the solvent, 98.5% conversion rate and 96% benzoic acid selectivity were obtained. [ABSTRACT FROM AUTHOR]

Novel heterogeneous catalytic system comprised of palladium nanoparticles (NPs) immobilized into the ionic liquid based periodic mesoporous organosilica (Pd@PMO‐IL) have been described for the model acylation reaction toward the facile construction of acylated ketones. A straightforward grafting method has been adopted for the functionalization of PMO containing 1‐methyl‐3‐(trimethoxysilylpropyl)‐imidazolium chloride (IL) by utilizing uncondensed alkoxy and hydroxy groups, thereby eliminating the need for an additional silicon source. The synthesized catalyst‐ Pd@PMO‐IL was characterized by XRD, N2 adsorption/desorption, TGA, FT‐IR, 29Si(CP‐MAS), 13C(CP‐MAS)‐NMR, XPS, ICP‐OES, FE‐SEM, and HR‐TEM techniques to confirm the anchoring of 1‐methyl‐3‐(trimethoxysilylpropyl)‐imidazolium chloride and Pd in the catalyst. The catalyst Pd@PMO‐IL demonstrated high catalytic activity in the model acylation reaction, along with other aldehyde derivatives to produce corresponding acylated ketones from moderate to excellent yields. Results from XPS analysis revealed the in‐situ reduction of PdII in the fresh catalyst to Pd0 at the reaction condition. HR‐TEM analysis confirmed the presence of 5–9 nm size of Pd NPs formed inside the mesopores of PMO‐IL support. Further, the catalyst was recycled for four consecutive cycles and showed insignificant loss in catalytic activity. The imidazolium in the PMO‐IL support could be the reason for successful stabilization and uniform distribution of insitu generated Pd NPs in the catalyst, resulting in highly active and recyclable catalytic system. [ABSTRACT FROM AUTHOR]

Fine‐tuning the interfacial sites within heterogeneous catalysts is pivotal for unravelling the intricate structure–property relationship and optimizing their catalytic performance. Herein, a simple and versatile mixed‐dimensional assembly approach is proposed to create nanocrystal‐on‐nanowire superstructures with precisely adjustable numbers of biphasic interfaces. This method leverages an efficient self‐assembly process in which colloidal nanocrystals spontaneously organize onto Ag nanowires, driven by the solvophobic effect. Importantly, varying the ratio of the two components during assembly allows for accurate control over both the quantity and contact perimeter of biphasic interfaces. As a proof‐of‐concept demonstration, a series of Au‐on‐Ag superstructures with varying numbers of Au/Ag interfaces are constructed and employed as electrocatalysts for electrochemical CO2‐to‐CO conversion. Experimental results reveal a logarithmic linear relationship between catalytic activity and the number of Au/Ag interfaces per unit mass of Au‐on‐Ag superstructures. This work presents a straightforward approach for precise interface engineering, paving the way for systematic exploration of interface‐dependent catalytic behaviors in heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Herein, a new two‐dimensional (2D) Ce‐organic frameworks (referred to as SLX‐4) was achieved by traditional solvothermal conditions. Initial studies of SLX‐4 toward Hantzsch reaction showed that good catalytic activity can be obtained under mild conditions, giving the desired 1,4‐dihydropyridines in moderate to high yields. The catalyst could be reused at least 4 times keeping good catalytic activity. Moreover, compared to the previously reported MOFs catalysts for Hantzsch reactions, SLX‐4 was stable in most acidic and basic environment, and gave comparable yield. [ABSTRACT FROM AUTHOR]

ABSTRACT Two novel Cr (III) and Ru (III) salen complexes based on {3,4‐Bis‐[(5‐chloro‐2‐hydroxy‐benzylidene)‐amino]‐phenyl}‐phenyl‐methanone ligand (CSAB) were synthesized. The complexes were characterized using various spectral and analytical methods. The catalytic performance of the CSAB complexes was investigated via a four‐component condensation reaction involving aromatic aldehydes, rhodamine, morpholine, and 5‐aminotetrazole under mild, environmentally friendly conditions. Different Lewis acids, bases, ionic liquid catalysts, solvents, and catalyst amounts were assessed to optimize the reaction parameters. Both catalyst systems demonstrated robust catalytic activity under strictly managed conditions, with the heterogeneous catalyst CSAB‐Ru showing superior efficacy compared to the homogeneous CSAB‐Cr catalyst. The study confirmed the catalytic capabilities of both complexes and evaluated their recyclability and reusability. The heterogeneous catalyst (CSAB‐Ru) could be reused seven times, whereas the homogeneous catalyst (CSAB‐Cr) could be recycled four times. Both complexes demonstrated strong catalytic activity and selectivity, resulting in high product yields. The study provides insights into the synthetic applications of novel CSAB complexes, highlighting their potential in organic transformations. It emphasizes their ease of use, safety, stability, component availability, quick reaction times, and high yields, making them promising for future industrial applications. [ABSTRACT FROM AUTHOR]

A functionalized Hf(IV)-based metal–organic framework (MOF) was synthesized, characterized, and successfully employed as a highly sensitive and selective fluorometric sensor for (1,1-diamino-2,2-dinitroethylene) FOX-7, which is a significant nitro explosive. The fluorescent sensor (MOF), denoted as CSMCRI-KNC′, exhibited a turn-off fluorescence signal towards FOX-7 in a water medium even in the presence of other potentially competitive explosives. The limit of detection (LOD) value for the detection of FOX-7 is fairly low (189 nM), and the response time is extremely rapid (<20 s). The sensing mechanism was investigated in detail and found to be based on non-covalent interactions, fluorescence resonance energy transfer (FRET), and photo-induced electron transfer (PET) processes. The sensing medium (water), detection time, sensitivity, and selectivity demonstrate the great potential of CSMCRI-KNC′ in the fluorescence-based sensor field. Additionally, the MOF was utilized as an efficient, recyclable, and heterogeneous catalyst for Knoevenagel condensation between barbituric acid and aromatic aldehydes in the presence of ethanol in an eco-friendly reaction medium. The present catalytic methodology has several attractive features, including mild reaction conditions, a short reaction time, high atom economy, and tolerance of various functional moieties. The catalyst could be recovered and reused successively without any remarkable loss in its catalytic activity. Moreover, the "hot filtration method (Sheldon's test)" has also been established to ensure the heterogeneity of the catalyst. Furthermore, the plausible mechanism of the catalysis is well presented. [ABSTRACT FROM AUTHOR]

ABSTRACT Catalyst design and fabrication with safe and affordable components and methods is a high‐value‐added business. In this work, a vitamin‐based hybrid nanomaterial (PMoB1) is prepared by simple stirring of thiamine hydrochloride (vitamin B1, VB1) as an inexpensive commercially available biologically active compound with phosphomolybdic acid (PMo12) in acidic aqueous solution to catalyze selective oxidation of sulfides using aqueous H2O2. A small amount of this heterogeneous catalyst drives rapidly the sulfoxidation reaction under mild and solvent‐free conditions facilitating the product separation and reducing significantly the environmental impacts. The main factors of the catalytic reaction were optimized by the central composite design (CCD) method. The solid catalyst tolerates a wide range of pH and retained its structural integrity even at alkaline solution (pH = 11). PMoB1 composed of two VB1 and one PMo12 was found to be partially reduced based on 13P NMR and UV–Vis spectra. An amorphous structure with aggregated nanoparticles with sizes ranging between 50 and 70 nm and a specific surface area of 35 m2/g are important reasons for enhanced catalytic activity and selectivity. Nevertheless, non‐covalent interactions such as hydrogen bonding and the π–π stacking can also significantly affect the catalyst performance. Given the scavenging tests and spectral evidences, a non‐radical mechanism involving peroxo species is postulated. The catalysis is shown to be truly heterogeneous while the solid catalyst largely maintains its structural integrity during the recycling test. [ABSTRACT FROM AUTHOR]

Benzothiazole derivatives, a class of heterocyclic compounds, hold significant relevance in medicinal chemistry, materials science, and agrochemicals due to their diverse biological activities and applications. The conventional synthetic routes often involve harsh conditions and generate significant waste, prompting the exploration of more sustainable approaches. This work offers a comprehensive analysis of the developments in the use of heterogeneous catalysts for the production of benzothiazole derivatives, covering research from 2013 onward. Compared to traditional techniques, heterogeneous catalysts provide improved sustainability, efficiency, and recyclability. The review covers many heterogeneous catalysts and discusses their selectivity, recyclability, and catalytic activity. The utilization of heterogeneous catalysts is noteworthy as it facilitates the synthesis process's overall sustainability by allowing for milder reaction conditions, less environmental effect, and easier catalyst separation and recovery. The potential of heterogeneous catalysis in promoting the production of benzothiazole derivatives and satisfying the increasing need for these substances in various industrial applications is also highlighted. [ABSTRACT FROM AUTHOR]

We are reporting a convenient method for the synthesis of bis(indolyl)methane derivatives from relatively cheap and commercially available chemicals such as indoles and aldehydes in a one‐pot procedure using Ga‐MCM‐41‐SO3H heterogeneous catalyst. Notably, the use of this catalyst has resulted in high yield of products (up to 98 %) under mild conditions, and the catalyst was found to be stable and reusable, retaining its highly catalytic activity even after five runs. Interestingly, two alkaloids Arsindoline A and Turbomycine B were successfully synthesized in the employment of this catalyst. These findings suggest that Ga‐MCM‐41‐SO3H could be a promising alternative to traditional acid homogeneous catalysts in the synthesis of bis(indolyl)methane derivatives, offering several advantages including ease of separation and reuse, high stability, and low toxicity. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of a new type of chiral crystalline organic porous salt CF2 derived from the ionic reaction between tetrakis(4‐sulfophenyl)methane (TSPM) and the tetra‐(S)‐prolylamide of tetrakis(4‐aminophenyl)methane, (S)‐TPPM, and its ability to stabilize 2 nm palladium nanoparticles to give a novel, nonpyrophoric, chiral, catalytic material Pd@CF2. The preparation of the catalyst was very simple and conducted in water. The heterogeneous catalytic performance of Pd@CF2 was tested in hydrogen reductions of olefins and substituted nitroaromatic compounds using Pd/C as a comparison to determine the specific features of the novel catalyst. Although both types of catalysts exhibited similar catalytic activity in case of reductions of diphenylacetylene and nitrobenzene, Pd@CF2 predominantly promoted the reduction of p‐nitrobenzaldehyde to p‐aminobenzyl alcohol whereas Pd/C gave p‐toluidine. The reduction of p‐dinitrobenzene led to predominant formation of p‐nitrophenylhydroxylamine if promoted by the novel catalyst and to a mixture of products if promoted by Pd/C. In addition, the introduction of p‐alkoxy groups onto nitrobenzenes slowed down the reduction with Pd@CF2 but had no influence on Pd/C activity. A hypothesis ascribing these observations to dissimilar equilibrium distributions of nitro and polar groups within the organic framework and the palladium metal surface is proposed to rationalize the selectivity of the novel catalytic material. [ABSTRACT FROM AUTHOR]

The composite Fenton catalyst was prepared by attaching MgCo2O4 to the surface of g‐C3N4 using a one‐pot method after preparing MgCo2O4 through co‐precipitation. The microstructure of the composites was analyzed using X‐ray diffraction (XRD) and other characterization methods. The catalytic activity of the composites towards tetracycline (TC) was studied, and a possible catalytic mechanism was proposed. The experimental results indicate that the degradation of TC by MgCo2O4@g‐C3N4 reached almost 99.0 % within 30 min in the presence of PMS and visible light. The combination of MgCo2O4 and g‐C3N4 improved the absorption of visible light, and the energy level‐matched heterojunction facilitated the separation of photogenerated electrons and holes, accelerating the redox cycle of ≡Co3+/≡Co2+. The free radical quenching experiment confirmed that the main active substances were free radical ⋅O2− and 1O2. The one‐step synthesis of composite catalysts exhibits high catalytic performance and good stability, offering a potential solution for the efficient treatment of tetracycline wastewater. [ABSTRACT FROM AUTHOR]

This work presents the synthesis and characterization of materials that contain Sn metal clusters formed by ligands of trimesic acid (Sn-BTC) or 5-sulfobenzene-1,3-dicarboxylic acid (Sn-H3-5-SIP). These catalysts were used to convert levulinic acid with ethanol to produce ethyl levulinate under mild reaction conditions. The characterization results confirmed that Sn is mainly present in the cassiterite crystalline phase with a tetragonal rutile structure in octahedral and tetrahedral coordination in the materials. The assembly of trimesic acid (a hard base) with metal species (Sn) results in the formation of acid and thermally stable metal–organic frameworks. The use of 5-sulfobenzene-1,3-dicarboxylic acid instead of trimesic acid in the synthesis incorporates sulfonic groups in the material, enhancing the total acidity of the Sn-H3-5-SIP catalyst compared to the Sn-BTC material. The Sn-H3-5-SIP catalyst exhibited the highest catalytic activity when converting levulinic acid with ethanol, resulting in a turnover frequency (TOF) of 0.0495 s−1, which is a 50% increase compared to the TOF of the Sn-BTC catalyst (0.0329 s−1). This result can be attributed to its higher concentration of acid sites (2.23 ± 0.05 mmol H+/gcat) and specific area (139 m2/g). Thus, materials containing tin metal clusters and sulfonic groups are promising materials that could be used as catalysts for synthesizing ethyl levulinate under mild reaction conditions. [ABSTRACT FROM AUTHOR]

This study reveals that the synthesis of a novel heterogeneous gaur gum-supported DABCO functionalized nickel(II)catalyst and its application for the synthesis of 2-amino-3-cyano-7-hydroxy-4H-chromenes. The synthesized GG@Ni(II) catalyst was characterized by FT-IR, XRD, EDX, and SEM techniques. The catalytic activities of this synthesized heterogeneous catalyst were examined in one-pot multicomponent synthesis of chromene derivatives under ultrasonic condition. A simple, benign and highly efficient ultrasound-mediated route was designed to produce chromene derivatives via one-pot, multicomponent reaction of aldehyde, malononitrile, and resorcinol at room temperature. The ultrasound-mediated synthetic route was studied here exhibits some remarkable advantages such as short reaction times, green reaction conditions, operational simplicity, high yields, and easy work-up and purification steps. In addition to this interestingly found that there was unnoticeable loss of reactivity when the catalyst was quantitatively recovered from the reaction medium and recycled up to five times. [ABSTRACT FROM AUTHOR]

In this research, microorganisms were used to produce Gd2ZnMnO6 NFs in a biological process instead of a chemical method as a nanocatalyst. Considering the capability of the microorganisms to synthesize nanofibrous (NFs) upon exposure to metal ions, microorganisms were employed to produce Gd2ZnMnO6 NFs through a biological process. The utilization of chemical modification to fabricate environmentally friendly heterogeneous nanocatalysts has proven to be highly appealing in the context of synthesizing 3-aryl-2-oxazolidinones using alkenes, carbon dioxide, and amines in an aqueous solution. The role of diverse variables in the creation of 3-aryl-2-oxazolidinones has been thoroughly investigated. Notably, Gd2ZnMnO6 NFs demonstrates remarkable efficiency in the production of 3-aryl-2-oxazolidinones due to its unique morphology. The morphology of Gd2ZnMnO6 NFs contributed to the creation of a desirable outer layer for the creation of 3-aryl-2-oxazolidinones. The findings demonstrated that the utilization of Gd2ZnMnO6 nanofibers positively impacts the effectiveness of the creation of 3-aryl-2-oxazolidinones. This can be attributed to the nanofibers' impressive mechanical and ionic internal characteristics, as well as their exceptional thermal sustainability and persistent colloidal sturdiness. Consequently, employing the host–guest method, the system could be regarded as an exemplary nanocatalyst. A diverse array of olefins was successfully transformed into desirable products, independent of the electronic nature of the substitutes. The involvement of heterogeneous mixtures did not impede the progression of the reaction. Moreover, the 3-aryl-2-oxazolidinones were easily distinguished from the Gd2ZnMnO6 nanofibers, and the medium exhibited the ability to undergo multiple cycles of usage without experiencing a notable decline in their catalytic activity and selectivity. This approach offers notable advantages, including a strong economic capability and the potential to withstand functional groups. Synthesis of biogenic Gd2ZnMnO6 nanofibrous for creation of 3-Aryl-2-oxazolidinones from alkenes, carbon dioxide, and aminesSynthesis of biogenic Gd2ZnMnO6 nanofibrous for creation of 3-Aryl-2-oxazolidinones from alkenes, carbon dioxide, and amines [ABSTRACT FROM AUTHOR]

Biomimetic heterogeneous catalysts were prepared by immobilization of meso‐tetrakis(4‐carboxyphenyl)porphyrinatomanganese(III) acetate (MnTCPP) and meso‐tetrakis(4‐carboxyphenyl)porphyrinatoiron(III) chloride (FeTCPP) on graphitic carbon nitride (g‐C3N4) nanosheets. The anchored catalysts were characterized by various techniques such as scanning electron microscopy, thermogravimetric analysis, powder X‐ray diffraction, ultraviolet visible, photoluminescence, flame atomic absorption, and Fourier transform infrared spectroscopy. The thermogravimetric analysis demonstrated that the prepared catalysts were thermally stable up to almost 350°C, exhibiting high thermal stability. In the following, the catalytic efficiency of the prepared nanocatalyst was also investigated for the oxidation of various olefins with hydrogen peroxide (as a green oxidant) and the effect of various parameters which may affect the catalytic efficiency was optimized. The maximum conversion (100% for α‐methylstyrene and 97% for cyclooctene) was obtained in the presence of MnTCPP@C3N4. The Mn porphyrin nanocatalyst shows higher catalytic efficiency compared to the Fe porphyrin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pd/DUT-67-PZDC(10) catalyst with highly dispersed Pd NPs was prepared. • The hierarchically microporous structural property of the DUT-67-PZDC support is beneficial for the stabilization of Pd NPs. • The dual N sites on the DUT-67-PZDC(10) support could act as excellent proton buffers to stimulate the O-H bond cleavage in FA. • The ultrasmall size (1.7 nm) and high dispersion of Pd NPs could expose more catalytic active sites. • The Pd/DUT-67-PZDC(10) catalyst shows an initial TOF value of 2572h−1, 100 % FA conversion and H 2 selectivity, and excellent stability at 60 °C. The highly dispersed ultrasmall palladium nanoparticles (Pd NPs) (1.7 nm) were successfully immobilized on a N -containing metal–organic framework (MOF, DUT-67-PZDC) using a co-reduction method, and it is used as an excellent catalyst for formic acid dehydrogenation (FAD). The optimized catalyst Pd/DUT-67-PZDC(10, 10 wt% Pd loading) shows 100% hydrogen (H 2) selectivity and formic acid (FA) conversion at 60 °C, and the commendable initial turnover frequency (TOF) values of 2572 h−1 with the sodium formate (SF) as an additive and 1059 h−1 even without SF, which is better than most reported MOF supported Pd monometallic heterogeneous catalysts. The activation energy (Ea) of FAD is 43.2 KJ/mol, which is lower than most heterogeneous catalysts. In addition, the optimized catalyst Pd/DUT-67-PZDC(10) maintained good stability over five consecutive runs, demonstrating only minimal decline in catalytic activity. The outstanding catalytic performance could be ascribed to the synergistic corporations of the unique structure of DUT-67-PZDC carrier with hierarchical pore characteristic, the metal-support interaction (MSI) between the active Pd NPs and DUT-67-PZDC, the highly dispersed Pd NPs with ultrafine size serve as the catalytic active site, as well as the N sites on the support could act as the proton buffers. This work provides a new paradigm for the efficient H 2 production of FAD by constructing highly active heterogeneous Pd-based catalysts using MOF supports. [ABSTRACT FROM AUTHOR]

Herein, the development of a niobium-based metal–organic framework (Nb-MOF) designed to serve as a catalytic support for the production of hydrogen (H2) from sodium borohydride (NaBH4) is reported. The Nb-MOF was synthesized via a solvothermal method using niobium ammoniacal oxalate (AmOxaNb) as the metal source and 1,4-benzenedicarboxylic acid (BDC) as the ligand. The resulting MOF was characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The characterization study confirmed the successful synthesis of Nb-MOF. The catalytic activity was optimized by examining five key factors: (i) platinum (Pt) and cobalt (Co) bimetallic compositions (ranging from 1:0 to 0:1 mmol), (ii) NaBH4 concentration (0.2, 0.3, 0.4, and 0.5 mol L−1), (iii) the Nb-MOF/Pt–Co catalyst dose (0.05, 0.10, 0.20, and 0.40 mmol), (iv) sodium hydroxide (NaOH) concentration (0.01, 0.05, 0.1, and 0.2 mol L−1), and (v) system temperature (293.15, 298.15, 303.15, 313.15, and 323.15 K). The optimal catalyst was identified as Nb-MOF supporting a Pt-Co bimetallic composition in a 0.4:0.6 mmol ratio, achieving a hydrogen generation rate (HGR) of 1473 mL min−1 gcat−1 and an activation energy of 19.2 kJ mol−1. Furthermore, this catalyst maintained its efficiency over 20 cycles, demonstrating significant potential as a sustainable solution for H2 evolution from NaBH4. [ABSTRACT FROM AUTHOR]

BACKGROUND: The main characteristic features of nickel–copper‐catalyzed azide–alkyne click (Ni‐CuAAC) reactions for production of 1,2,3‐triazoles are regioselectivity and the reaction proceeding under mild conditions. The use of copper salts as catalysts often leads to challenges like contamination of the prepared triazoles. NiO/Cu2O nanocomposites (NCs) were utilized in Ni‐CuAAC reactions as heterogeneous nanocatalysts to achieve the production of some 1,4‐disubstituted 1,2,3‐triazoles in high chemical yields under microwave irradiation. RESULTS: The preparation of NiO/Cu2O NCs was performed through the coprecipitation of NiO nanoparticles on Cu2O surface. The prepared catalyst was used for catalyzing a reaction between benzoyl azides and phenylacetylene under optimized reaction conditions. The NiO/Cu2O NCs exhibited high catalytic activity compared to Cu2O nanoparticles. In addition, by utilizing ethanol–water as the solvent system under microwave irradiation, higher yields and efficient product separation were observed. CONCLUSION: This study investigated the proficiency of NiO/Cu2O NCs as effective nanocatalysts for the selective synthesis of some 1,4‐disubstituted 1,2,3‐triazole derivatives. Employing heterogeneous nanoparticle catalysts, such as Cu2O and NiO/Cu2O, offers several advantages over homogeneous catalytic systems. These include easier catalyst separation and recovery, potential for catalyst reuse and the ability to fine‐tune the catalytic properties by modulating the nanoparticle composition and structure. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Mg and its related solid base catalysts have always been thought of with weak or medium basicity. Herein, we present the synthesis of Mg single atom catalyst (Mg1/NPC) with strong basicity by tuning its coordination environment, which shows unusual activity in strong‐base‐catalyzed transesterification reaction. Mg1/NPC were obtained through impregnation‐pyrolysis method, results manifest Mg single atoms are embedded in nitrogen doped carbon in penta‐coordination (Mg‐C3N2) which endows Mg single atoms with strong basicity and is in contrast to traditional alkaline‐earth metal oxides. The novel Mg1/NPC exhibits excellent activity (40.2%) and stability in transesterification of methanol and ethylene carbonate to produce dimethyl carbonate (DMC), outperforming all state‐of‐the‐art Mg‐based solid base catalysts thus far reported as well as Ca, Na, and K‐based catalysts with superbasicity (2.5%–39.2%). This work might pave the way for the advancement of novel solid base catalysts with extraordinary sources of basicity for multifarious applications. [ABSTRACT FROM AUTHOR]

Catalytic cycloaddition of CO2 with propylene oxide (PO) is a sustainable pathway for the synthesis of propylene carbonate (PC), and the design of efficient heterogeneous catalysts is a hot research topic in both C1 chemistry and functional materials. In this work, graphitic carbon nitride (g‐C3N4) materials were prepared using urea (U) and melamine (M) as precursors through one‐step thermal condensation and then applied as catalyst supports for ZnBr2. As heterogeneous catalysts, the synthesized composites (ZnBr2/g‐C3N4‐MU) exhibited higher activity in the cycloaddition reaction of CO2 to PC than ZnBr2/g‐C3N4‐M and ZnBr2/g‐C3N4‐U. The preparation temperature of ZnBr2/g‐C3N4‐MU could affect the distributions of nitrogen species and acidic strength, which thus determined the final catalytic activity. More importantly, the loading of ZnBr2 not only introduced acidic sites but also enhanced the strength of alkaline sites of g‐C3N4‐MU, enabling ZnBr2/g‐C3N4‐MU materials as acid–base bifunctional catalysts in cycloaddition of CO2 with PO. [ABSTRACT FROM AUTHOR]

The development of heterogeneous palladium catalysts has shown continuous vitality in the field of catalysis and materials. In this work, we report one concise free radical polymerization approach to accomplish the aromatic palladium trimer functionalized polymers PSSy‐[Pd3]+ (2) and its derived palladium nanoparticles (3). Full characterizations could confirm the successful combination of cationic [Pd3]+ or nanoparticles with poly(p‐sulfonated styrene) skeleton. Compared to their monomeric tri‐palladium precursor (1) and common Pd(dba)2, Pd(PPh3)4, Pd(OAc)2, heterogeneous PSSy‐[Pd3]+ (2) shows much superior catalytic activities (0.15 mol %, TOF=1333.3 h−1) in the SMCC reaction. The identically ligated PdNPs (3) are formed in‐suit in the presence of NaBH4 and accomplish quantitative reduction of 4‐nitrophenol in just 320 s (0.50 mol %, TOF=2250 h−1). Moreover, these heterogeneous catalysts are reused for 5–6 times without significant loss of catalytic activity. Their superior catalytic ability is probably attributed to the synergistic effect of polymer entanglement and the tri‐palladium fragment. This work enlightens that the immobilization of palladium clusters or nanoparticles by polymerization could offer multiple advantages in stability, efficiency and recyclability for their involved catalyses and show far‐reaching future implications. [ABSTRACT FROM AUTHOR]

We present the use of an amine functionalized two-dimensional clay i.e., aminoclay (AC), in the chemistry of a three-dimensional metal–organic framework (MOF) i.e., MIL-101(Cr), to prepare MIL-101(Cr)/AC composites, which are exploited as catalysts for efficient conversion of CO2 gas into cyclic carbonates under ambient reaction conditions. Three different MOF nanocomposites, denoted as MIL-101(Cr)/AC-1, MIL-101(Cr)/AC-2, and MIL-101(Cr)/AC-3, were synthesized by an in situ process by adding different amounts of AC to the precursor solutions of the MIL-101(Cr). The composites were characterized by various techniques such as FT-IR, PXRD, FESEM, EDX, TGA, N2 adsorption, as well as CO2 and NH3-TPD measurements. The composites were exploited as heterogeneous catalysts for CO2 cycloaddition reactions with different epoxides and the catalytic activity was investigated at atmospheric pressure under solvent-free conditions. Among all the materials, MIL-101(Cr)/AC-2 shows the best catalytic efficiency under the optimized conditions and exhibits enhanced efficacy compared to various MIL-101(Cr)-based MOF catalysts, which typically need either high temperature and pressure or a longer reaction time or a combination of all the parameters. The present protocol using MIL-101(Cr)/AC-2 as the heterogeneous catalyst gives 99.9% conversion for all the substrates into the products at atmospheric pressure. [ABSTRACT FROM AUTHOR]

5‐Hydroxymethylfurfural (5‐HMF) derived from lignocellulose represents an important platform molecule that could be employed in the selective hydrogenation of the furan ring to prepare 5‑hydroxymethyltetrahydrofurfural (HMTHF). However, the reported catalytic systems for the synthesis of HMTHF using 5‐HMF still require additional hydrogen pressure. In this study, the Pd/ZrO2 catalyst with uniformly dispersed Pd nanoparticles was prepared via a simple impregnation reduction process. This catalyst exhibited excellent catalytic activity and selectivity for the hydrogenation of 5‐HMF to HMTHF. High HMTHF yields up to 92.3% were produced under mild reaction conditions of ambient hydrogen pressure and room temperature in methanol solvent. This result was superior to the most catalytic systems that had been reported so far. The mechanism study revealed that the active hydrogen species on the surface of the Pd nanoparticles and the reaction solvent in this study were the pivotal factors influencing the hydrogenation of furan rings in 5‐HMF. [ABSTRACT FROM AUTHOR]

ABSTRACT Exploring the relationship between the structure of active site and the activity in molecular level and investigating the reason for deactivation are extremely important in designing the highly active catalyst. In this paper, new self‐assembly Schiff‐base Pd/Cu nanosheets supported on the surface of graphene oxide (GO) (called as GO@Hpmaba‐Pd/Cu) were fabricated and characterized. Among them, GO@Hpmaba‐Pd0.2/Cu0.8 exhibited a high activity with a TOF value of up to 95,357 h−1 and substrate suitability in Suzuki cross‐coupling reaction. GO@Hpmaba‐Pd0.2/Cu0.8 could be reused at least 13 times. GO@Hpmaba‐Pd0.2/Cu0.8 was a heterogeneous catalyst and the catalysis occurred on the surface. The truly active sites included Pd/PdO/CuO/PdCu3 formed in situ on the surface of the hetero‐organometallic Pd/Cu nanosheet during catalysis. The synergistic effects among these active sites could be described as that the electrons transferred from GO to CuO (PdO) or to Pd via ligand (Hpmaba) and subsequently electrons transferred from CuO (PdO) to Pd. These made more electron negative palladium, enhancing the oxidation addition between palladium and aryl halide and prompting the activity. The deactivation of catalyst was mainly caused by some destroyed organometallic in the nanosheet, residues adsorbed on catalytic surface, loss of active Pd due to the leaching with increase of recycling, and the aggregation of active metals. [ABSTRACT FROM AUTHOR]

ABSTRACT A3 coupling reaction is a multicomponent reaction (MCR) involving aryl aldehydes, phenyl acetylenes and amines to synthesize a variety of biologically active propargylamine derivatives. Herein, we report the preparation of cube‐shaped CuFe2O4 nanoparticles (NPs) via the hydrothermal method in the presence of Lantana camara flower (LCF) extract to use them as catalysts to synthesize propargylamine derivatives. X‐ray diffraction study confirms the formation of CuFe2O4 NPs with cubic spinel structures. In the presence of LCF extract, cube‐shaped CuFe2O4 NPs are formed predominantly irrespective of the type of alkali used as the hydrolyzing agent. However, a mixture of nearly spherical and cube‐shaped particles has been formed in the absence of additives. The synthesized CuFe2O4 NPs exhibit superparamagnetic behaviour and are magnetically ordered. The synthesized cube‐shaped CuFe2O4 NPs exhibit excellent catalytic activity in the A3 coupling reaction between benzaldehyde, piperidine and phenylacetylene to give propargylamine with a yield of 90% under the optimum conditions. The catalyst is highly stable and magnetically retrievable facilitating reusability for up to five cycles without considerable loss of catalytic activity. The protocol is suitable for the synthesis of a diverse range of propargylamine derivatives with moderate to excellent yield. [ABSTRACT FROM AUTHOR]

Two novel rare earth-substituted tungstoantimonates [H2N(CH3)2]8Na12[Dy2(H2O)6(tar)(Sb2W21O72)]2·40H2O (DySbW) and [H2N(CH3)2]6Na14[Ho2(H2O)6(tar)(Sb2W21O72)]2·25H2O (HoSbW) (H4tar = tartaric acid) were synthesized. The meso-polyanions are alternately linked by {Na3(H2O)3} clusters and DL-tar ligands to form 1D chains. Notably, HoSbW exhibits excellent catalytic activity and high stability for the synthesis of isoindolinones using EtOH as a green solvent. [ABSTRACT FROM AUTHOR]

Since catalytic hydrogenation of nitroarenes is of great significance in chemical industry, it is imperative to develop an inexpensive and efficient catalyst. To develop high performance catalysts for hydrogenation of nitroarenes, Co-Ce-@Salen/Melamine was prepared by mixing Co-Ce-@Salen complex with melamine in 1:1 mol ratio in a mortar and grinded completely. Further, Co/CN-CeO2-Melm-T was fabricated via pyrolysis of Co-Ce-@Salen/Melamine precursor in existence of argon atmosphere. Upon Co/CN-CeO2-Melm-T3 were applied for catalysis on the reaction of hydrogenation of nitroarenes, it exhibited outstanding catalytic performance in terms of catalytic activity, selectivity, universality and reusability for hydrogenation of nitroarenes. Spectral analysis revealed that the synergistic interaction among highly dispersed metallic Co for the dispersion and activation of hydrogen, unique surface site of CeO2 for oxygen vacancies, high absorbance ability originated from alkalinity and unique high surface area of Co/CN-CeO2-Melm-T3 dominated the highly catalytic activity for the reaction of hydrogenation of nitroarenes. Notably, 3d-4f hetero-metal coordination polymers have seldom been directly employed as a precursor for preparation of inexpensive hetero-metal catalyst. Therefore, this tactic provided an alternative route to fabricate 3d-4f inexpensive hetero-metallic heterogeneous catalyst for hydrogenation of nitroarenes with high atomic economy. [ABSTRACT FROM AUTHOR]

In this work, we applied commercially available 2-pyridinecarboxylic acid to modify cellulose by simple manipulations, and then anchored low-toxicity metal nickel onto the modified cellulose to prepare the heterogeneous catalyst (CL-AcPy-Ni). The obtained catalyst was characterized by FT-IR, TG-DSC, BET, XRD, SEM-EDS, ICP-OES, XPS, and GPC. The catalytic performance of CL-AcPy-Ni in the Suzuki cross-coupling reaction was investigated using 4-methyl iodobenzene and phenylboronic acid as the model substrates reacting in THF under 120 °C for 24 h. The catalytic ability of CL-AcPy-Ni for various halobenzenes and phenylboronic acid derivatives was also further investigated under optimal conditions and demonstrated good catalytic activity, and a series of diaryls were successfully synthesized. Finally, this green nickel-based catalyst could be reused for five successive cycles by simple centrifugation. [ABSTRACT FROM AUTHOR]

In this work, a Pd(II)-C,N-cyclometalated complex was grafted to polysiloxanes via azide–alkyne cycloaddition. The obtained polymer–metal complex (Pd-PDMS) acts as a catalyst in the Suzuki–Miyaura reaction. Pd-PDMS was drop-casted onto a carbon fiber support, and the resulting membrane demonstrated catalytic activity in the cross-coupling reaction without yield loss after several catalytic cycles. The catalytic membrane allows for easy catalyst recycling and provides ultra-low palladium levels in Suzuki–Miyaura reaction products. [ABSTRACT FROM AUTHOR]

Copper immobiolized onto the polyvinyl imidazole coated magnetic graphene oxide [MGO@PVimCu(I)] was synthesized and characterized by various analytical methods such as FT-IR, XRD, TGA, TEM, FESEM, VSM and ICP-OES. According to the FE-SEM and TEM results, the size of the snared nanoparticles in the polymer matrix was about 50–90 nm and the surface of the catalyst was rough. The loading percentage of copper onto the polyvinyl imidazole coated MGO was determined to be 17% using ICP-OES, which is far better than the many known metal-based heterogeneous catalysts. In the catalytic activity scrutiny, A3 coupling reaction for the preparation of propargylamines and coupling reaction of aryl halides with nucleophiles were aimed. In the presence of MGO@PVimCu(I), the corresponding products were gained in these reactions with moderate to excellent yields in aqueous medium (50–99%). This method demonstrates several considerable benefits including product yields, the use of various substrates, easy work-up, separation of catalyst by a simple external magnet, reusability of catalyst (at least four cycles), eco-friendliness, and avoidance of using any toxic solvent. The results of this study have shown that this catalyst can be a suitable candidate for other organic transformations. [ABSTRACT FROM AUTHOR]

Given the abundance of functional groups, meso- and macro-pores, and a high surface area, the piperazine-based poly(amic acid) was employed as a heterogeneous catalyst in the multicomponent reaction to prepare pyrrolidinone scaffolds in a green solvent, acting as a medium for mass transfer and crystallization solvent. The important parameters of the reaction were investigated to find the optimal reaction conditions. A conversion of 100% was obtained at reflux conditions within 30–100 min using a catalytic amount of 200 mg of piperazine-based poly(amic acid) per 2 mmol of reactants (100 mg of cat./1 mmol of reactant). The piperazine-based poly(amic acid) exhibited high recyclability and the recovered catalyst could be used in successive runs without worthy loss in its activity. This work revealed the catalytic activity of the piperazine-based poly(amic acid) as a promising functional polymeric heterogeneous catalyst for organic synthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeOOH/F-Ce composites exhibit excellent catalytic activity under visible light. • The two-dimensional porous structure facilitates the diffusion and transport of reactant molecules, enhancing the degradation efficiency. • The S-scheme heterojunction promotes visible light absorption and charge transfer, accelerating the Fe3+/Fe2+ cycle. The utilization of two-dimensional (2D) materials to construct heterogeneous catalysts provides opportunities for environmental remediation, while the incorporation of porous structures can further enhance catalytic performance. In this work, a porous 2D FeOOH/fluorine-cerium (F-Ce) nanosheet composite was designed and synthesized by a simple impregnation-precipitation method. The unique 2D porous structure of F-Ce promoted the high dispersion of FeOOH quantum dots (QDs) (∼1.4 nm) and their tight integration to form S-scheme heterojunctions. This structure offered a greater number of active sites, and significantly improved the capacity of light absorption and the separation and migration efficiency of photogenerated carriers, thus improving catalytic activity. This catalyst achieved a phenol removal rate of 98.1 % within 20 min during the photo-Fenton reaction, which significantly surpasses pure FeOOH (32.9 %) and F-Ce (21.7 %) alone. In particular, the optimized 14FeOOH/F-Ce catalyst achieved more than 95.0 % degradation efficiency within a remarkably short period of 5 min. Mott Schottky and in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) studies demonstrated that the S-scheme charge transfer mechanism of this heterojunction synergistically enhanced the catalytic activity of the Fenton-like reaction. This study provides valuable insights for designing efficient 2D porous heterojunction catalysts for visible-light-driven Fenton applications. [ABSTRACT FROM AUTHOR]

Through leveraging the abundant functional groups in fungi to effectively coordinate with metal ions, and incorporating the additional nitrogen species provided by the in situ encapsulated ZIFs shell layer, an iron single-atom catalyst Fe-TA@ZIF with an asymmetric Fe 1 -N 3 P 1 coordination structure was engineered, which exhibited impressive catalytic performance in the selective hydrogenation of nitroaromatics to anilines. [Display omitted] Iron, one of the most abundant elements on earth and an essential element for living organisms, plays a crucial role in our daily metabolism. In the field of catalysis, the development of high-performance catalysts based on less toxic iron element is also of significant importance for green chemistry and a sustainable future. To construct Fe-based heterogeneous catalysts with excellent hydrogenation performance, precise modulation of the atomic coordination structure is a key strategy for enhancing catalytic activity. In this study, we present an in-situ coating method for applying a zeolitic imidazolate framework (ZIF) onto the surface of fungal hyphae. The asymmetric coordination structure of Fe 1 -N 3 P 1 was precisely tailored by utilizing the phosphorus source from the fungus and the nitrogen source in the ZIFs. Detailed characterizations and density functional theory calculations revealed that the incorporation of ZIFs not only increased the specific surface area of catalysts, but also facilitated the dispersion of Fe 2 P nanoparticles into the Fe 1 -N 3 P 1 center, making the lowest reaction energy barrier and resulting in the best performance for nitrobenzene hydrogenation when compared to the Fe 2 P nanoparticles and clusters. This research introduces a novel design concept for constructing asymmetric monoatomic configuration based on the inherent characteristics of natural microorganisms and the exogenous porous coordination polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel yolk-shell Pd 4 Ir 1 /YSMSNs-NH 2 catalyst with highly dispersed PdIr alloy NPs was prepared. • The radially oriented mesoporous channels of Pd 4 Ir 1 /YSMSNs-NH 2 catalyst can promote mass transfer and increase accessibility. • The amine groups on the YSMSNs-NH 2 support can improve the dispersion and reduce the particle size of the PdIr active phases. • The ultrasmall size (1.4 nm) and high dispersion of PdIr alloy NPs could expose more catalytic active sites. • The Pd 4 Ir 1 /YSMSNs-NH 2 catalyst exhibits an initial TOF value of 5818 h−1 at 50 °C, with 100 % FA conversion and H 2 selectivity. Developing heterogeneous catalysts with exceptional catalytic activity over formic acid (HCOOH, FA) dehydrogenation is imperative to employ FA as an effective hydrogen (H 2) carrier. In this work, ultrasmall (1.4 nm) and well-dispersed PdIr nanoparticles (NPs) immobilized on amine-functionalized yolk-shell mesoporous silica nanospheres (YSMSNs) with radially oriented mesoporous channels have been synthesized by a co-reduction strategy. The optimized catalyst Pd 4 Ir 1 /YSMSNs-NH 2 (Pd/Ir molar ratio = 4:1) exhibited a remarkable turnover frequency (TOF) of 5818 h−1 and remarkable stability at 50 °C with the addition of sodium formate (SF), resulting in complete FA conversion and H 2 selectivity, exceeding most of the solid heterogeneous catalysts in previous reports under similar circumstances. Kinetic isotope effect (KIE) exploration indicates the cleavage of the C H bond is regarded as the rate-determining step (RDS) during the FA dehydrogenation process. Such excellent catalytic properties arise from the ultrafine and well-dispersed PdIr NPs supported on the nanosphere support YSMSNs-NH 2 , the electronic synergistic effect of PdIr alloy NPs, and the strong metal-support interaction (MSI) effect between the introduced PdIr NPs and YSMSNs-NH 2 support. This work offers a new paradigm for exploiting the highly effective silica-supported Pd-based heterogeneous catalysts over the dehydrogenation of FA. [ABSTRACT FROM AUTHOR]

AbstractIn this study, CuO@HNTs-SO3H was investigated as a novel eco-friendly heterogeneous solid acid catalyst prepared by straightforward co-precipitation method. Thus, the cost-effective CuO NPs was used to modify halloysite nanotubes initially, which were subsequently further functionalized with sulfonic acid. The prepared catalyst was analyzed by means of FT-IR, XRD, EDX, SEM and TGA methods. Its catalytic activity is investigated in the solvent-free one-pot condensation of various aromatic aldehydes, dimedone, and β-naphthol to produce tetrahydrobenzo[a]xanthen-11-one derivatives. A few benefits of the discovered method are its simple process, quick reaction time, high yields (96%), affordable cost, and the catalyst ability to be reused without losing its activity. [ABSTRACT FROM AUTHOR]

The preparation of a magnetically recoverable and reusable Fe3O4@benzothiazole-Cu(II) nanoparticles with their catalytic and electrochemical sensing properties are reported in this manuscript. The prepared Fe3O4@benzothiazole-Cu(II) nanoparticles are characterized using various analytical techniques, including XRD, FTIR, SEM, TEM, XPS, TGA and VSM analysis. The prepared system has shown good catalytic activity in the reduction of 2-NBA, achieving a reaction rate constant of 0.093 min−¹ in 2 min with a low catalyst loading. The synthesized catalyst also showed very high efficiency in the reduction of 4-nitro-phenol and methylene blue within 13 min and 4 min, respectively. The prepared material demonstrated good recovery yield and could be reused as a catalyst for multiple cycles without a significant loss in catalytic activity. It also exhibited a remarkable electrochemical sensing capability for the detection of ascorbic acid, H2O2, and paracetamol at various concentrations, as determined through cyclic voltammetry and impedance measurements. They exhibited clear redox transformations, indicating the electrochemical sensing ability of the prepared materials. [ABSTRACT FROM AUTHOR]

SBA-15 and organic ionic liquid were incorporated in a post-grafting technique for generating a bifunctional ionic liquid embedded mesoporous SBA-15. The prepared heterogeneous catalyst was employed for the first time to synthesize N-alkylated indoline-2,3-dione at mild conditions to afford excellent yields in a short reaction time. The synthesized DABCOIL@SBA-15 catalyst was meticulously characterized by various techniques, such as FT-IR, solid-state 13C NMR, solid-state 29Si NMR, small-angle X-ray diffraction (XRD), and N2 adsorption–desorption. Further, the morphological behavior of the catalyst was studied by SEM and TEM. The thermal stability and number of active sites were determined by thermogravimetric analysis (TGA). The Hammett equation was used to analyze the synergetic effect of the catalyst and substituent effects on the N-alkylated products of 5-substituted isatin derivatives, which resulted in a negative slope. This negative slope indicates a positive charge in the transition state. Notably, the DABCOIL@SBA-15 catalyst demonstrated its practicality by being reused for seven cycles with consistently high catalytic activity. [ABSTRACT FROM AUTHOR]

In this work, a novel heterogeneous catalyst consisting of peroxophosphotungstate, microporous MOF-808, and mesoporous SBA-15 was synthesized, characterized, and used to remove sulfides from model fuel. The prepared material, PW4@MOF-808@SBA-15, exhibits excellent catalytic activity with a desulfurization efficiency of 99.8% in 60 min for multicomponent simulated fuel, and the desulfurization rate can reach more than 90% after ten consecutive cycles. The excellent catalytic activity and reusability are attributed to the hierarchically porous hybrid material MOF-808@SBA-15, which can effectively encapsulate PW4 and provide a site for the oxidation of sulfides. [ABSTRACT FROM AUTHOR]

The synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) was made by utilizing newly synthesized heterogeneous mixed ligand-based Ni-phen MCM-41 catalyst with variety of aryl aldehydes (viz. electron donating, electron withdrawing, fused, disubstituted and unsaturated substituents), ethylacetoacetate, urea and ethanol as a solvent by using two different energy sources: conventional and ultrasonication methods. The effectiveness of the two methods was compared and found that the formation of Biginelli products in ultrasonication method (65–92% yield at 60 °C, 45 min) is better than the conventional method (63–90% yield at 78 °C, 2 h) by yield, temperature and time of the reaction. The formation, heterogeneous nature and morphology of the catalyst have been characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA) and N2 adsorption–desorption isotherm (BET) techniques. Moreover, the catalyst was recoverable, reusable and very much efficient for three consecutive runs without any significant loss of its catalytic activity. The heterogeneity nature of the recovered catalyst was checked by hot filtration test. [ABSTRACT FROM AUTHOR]

Single step surfactant assisted sol–gel technique was adapted to synthesize mesoporous tungstated zirconia (m-WZ). Amorphous WZs, with high surface area, were synthesized after calcination of as-synthesized materials at 550 °C for 6 h. These materials were well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Textural properties were established from N2 adsorption–desorption isotherm, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM). Pyridine adsorbed FTIR and NH3-TPD revealed reasonable amount of Brønsted and Lewis acid sites of m-WZs. m-WZs exhibited outstanding catalytic activities toward solvent free Knoevenagel condensation reaction of different aromatic aldehydes with malononitrile and ethyl cyanoacetate at room temperature. The developed catalysts were also employed to synthesize different industrially important fine chemicals. These catalysts had longer reusability and no visible drops were observed in catalytic activity even after several runs. [ABSTRACT FROM AUTHOR]

A new MOF (Co‐TIST) was synthesized from 2,4,6‐tris (imidazol‐1‐yl)‐1,3,5‐s‐triazine (TIST) and cobalt nitrate. TIST was prepared from the reaction of cyanuric chloride and imidazole and used as a ligand for the formation of MOF. After characterization of Co‐TIST by different methods, we have investigated the carbonyl‐Heck cross‐coupling reaction of aldehydes with aryl halides in the presence of Co‐TIST as a new heterogeneous catalyst. Various ketones were obtained in good to high yields by this method. The reactions did not require high temperature, additives, or large amounts of the catalyst. The catalyst was recycled in five consecutive runs with unimportant decrease in its catalytic activity. Notably, this is the first report of using a MOF for the carbonyl‐Heck cross‐coupling reaction of aryl halides and aldehydes. [ABSTRACT FROM AUTHOR]

Natural hematite supported cobalt (Co/Nat-Hem), a new heterogeneous catalyst, was successfully prepared by a simple impregnation technique. Textural, structural, functional groups and morphological aspects of the prepared catalyst were analyzed by BET, XRD, FT-IR, XRF, pHpzc, SEM-EDX methods. BET analysis shows that the Co/Nat-Hem catalyst has a specific surface area of ​​13.44 m2/g and a pore volume of 0.062 cm3/g. The SEM-EDX method showed that 7.19 wt% of the cobalt species were dispersed on the surface of the prepared catalyst. The catalytic activity of Co/Nat-Hem was evaluated by photo-Fenton oxidation of the dye Cong red (CR). The effect of reaction parameters on CR oxidation efficiency was investigated. Under optimal reaction conditions (1 g/L catalyst concentration, 0.2 mol/L H2O2 initial concentration and pH 3), the percentage of CR discoloration reaches 97% after 30 min. The Co/Nat-Hem catalyst achieved a synergistic ratio of 28.5%, which was added to the oxidation rate of the Nat-Hem catalyst. The stability of the Co/Nat-Hem catalyst was demonstrated by the limited activity of leachates in the homogeneous Fenton oxidation of CR. The phytotoxicity of the CR dye was tested during the irrigation of the bean (Vicia faba L.). [ABSTRACT FROM AUTHOR]

In PMS catalytic oxidation studies, we design and prepare a Mn3O4/CuO (CMO-2) composite catalyst using metal–organic frameworks (MOFs) as precursors. Compared with Mn3O4, its activated per-oxy-monosulfate activation catalyzed the degradation of pollutants with nearly six times higher activity efficiency. The experimental findings demonstrate that CMO-2 derived from metal–organic frameworks offer the advantages of wide adaptability to solution pH, along with improved versatility, stability, and recyclability. Further experiments involving radical scavenging, electrochemistry, and electron spin resonance (EPR) techniques confirm that the CMO-2 derived from MOF structures exhibit more significant interfacial engineering effects. This leads to an expansion of active interfaces, enhancing the accessibility and dispersion of active sites. Consequently, it significantly improves the efficiency of electron-transfer reactions and promotes a wide range of reactive oxygen species (ROSs), including SO4•− •OH and1O2. Based on the synergistic effect of copper-manganese bimetallic, the copper-manganese composite catalyst (CMO-2) prepared by doping 0.5 g of Cu-MOF showed the best catalytic activity in activating PMS, and the resulting ROSS could efficiently degrade organic pollutants. [ABSTRACT FROM AUTHOR]