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Chiral carboxylic acid production from renewable biomass by chemocatalysis is vitally important for reducing our carbon footprint, but remains underdeveloped. We herein establish a strategy that make use of a stereogenic center of biomass to achieve a rare example of D‐glyceric acid production with the highest yield (86.8 %) reported to date as well as an excellent ee value (>99 %). Unlike traditional asymmetric catalysis, chiral catalysts/additives are not required. Ample experiments combined with quantum chemical calculations established the origins of the stereogenic center and catalyst performance. The chirality at C4 in D‐xylose was proved to be retained and successfully delivered to C2 in D‐glyceric acid during C−C cleavage. The remarkable cooperative‐roles of Ag+ and Ag0 in the constructed Ag/γ‐Al2O3 catalyst are disclosed as the crucial contributors. Ag+ was responsible for low‐temperature activation of D‐xylose, while Ag0 facilitated the generation of active O* from O2. Ag+ and active O* cooperatively promoted the precise cleavage of the C2−C3 bond, and more importantly O* allowed the immediate fast oxidization of the D‐glyceraldehyde intermediate to stabilize D‐glyceric acid, thereby inhibiting the side reaction that induced racemization. This strategy makes a significant breakthrough in overcoming the limitation of poor enantioselectivity in current chemocatalytic conversion of biomass. [ABSTRACT FROM AUTHOR]

Ammonia borane (AB) has emerged as a promising chemical hydrogen storage material. The development of efficient, stable, and cost‐effective catalysts for AB hydrolysis is the key to achieving hydrogen energy economy. Here, cobalt phosphide (CoP) is used to anchor single‐atom Pt species, acting as robust catalysts for hydrogen generation from AB hydrolysis. Thanks to the high Pt utilization and the synergy between CoP and Pt species, the optimized Pt/CoP‐100 catalyst exhibits an unprecedented hydrogen generation rate, giving a record turnover frequency (TOF) value of 39911 molH2molPt−1min−1${\mathrm{mo}}{{{\mathrm{l}}}_{{{{\mathrm{H}}}_{\mathrm{2}}}}}{\mathrm{\ mo}}{{{\mathrm{l}}}_{{\mathrm{Pt}}}}^{{\mathrm{ - 1}}}{\mathrm{\ mi}}{{{\mathrm{n}}}^{{\mathrm{ - 1}}}}$ and turnover number of 2926829 molH2molPt−1${\mathrm{mo}}{{{\mathrm{l}}}_{{{{\mathrm{H}}}_{\mathrm{2}}}}}{\mathrm{\ mo}}{{{\mathrm{l}}}_{{\mathrm{Pt}}}}^{{\mathrm{ - 1}}}$ at room temperature. These metrics surpass those of all existing state‐of‐the‐art supported metal catalysts by an order of magnitude. Density functional theory calculations reveal that the integration of single‐atom Pt onto the CoP substrate significantly enhances adsorption and dissociation processes for both water and AB molecules, thereby facilitating hydrogen production from AB hydrolysis. Interestingly, the TOF value is further elevated to 54878 molH2molPt−1min−1${\mathrm{mo}}{{{\mathrm{l}}}_{{{{\mathrm{H}}}_{\mathrm{2}}}}}{\mathrm{\ mo}}{{{\mathrm{l}}}_{{\mathrm{Pt}}}}^{{\mathrm{ - 1}}}{\mathrm{\ mi}}{{{\mathrm{n}}}^{{\mathrm{ - 1}}}}$ under UV–vis light irradiation, which can be attributed to the efficient separation and mobility of photogenerated carriers at the Pt‐CoP interface. The findings underscore the effectiveness of CoP as a support for single‐atom metals in hydrogen production, offering insights for designing high‐performance catalysts for chemical hydrogen storage. [ABSTRACT FROM AUTHOR]

Engineering porous organic polymers (POPs) into 1D morphology holds significant promise for diverse applications due to their exceptional processability and increased surface contact for enhanced interactions with guest molecules. This article reviews the latest developments in nanofibrous POPs and their derivatives, encompassing porous organic polymer nanofibers, their composites, and POPs‐derived carbon nanofibers. The review delves into the design and fabrication strategies, elucidates the formation mechanisms, explores their functional attributes, and highlights promising applications. The first section systematically outlines two primary fabrication approaches of nanofibrous POPs, i.e., direct bulk synthesis and electrospinning technology. Both routes are discussed and compared in terms of template utilization and post‐treatments. Next, performance of nanofibrous POPs and their derivatives are reviewed for applications including water treatment, water/oil separation, gas adsorption, energy storage, heterogeneous catalysis, microwave absorption, and biomedical systems. Finally, highlighting existent challenges and offering future prospects of nanofibrous POPs and their derivatives are concluded. [ABSTRACT FROM AUTHOR]

Water molecules, which act as both solvent and reactant, play critical roles in photocatalytic reactions for methanol conversion. However, the influence of water on the adsorption of methanol and desorption of liquid products, which are two essential steps that control the performance in photocatalysis, has been well under‐explored. Herein, we reveal the role of water in heterogeneous photocatalytic processes of methanol conversion on the platinized carbon nitride (Pt/C3N4) model photocatalyst. In situ spectroscopy techniques, isotope effects, and computational calculations demonstrate that water shows adverse effects on the adsorption of methanol molecules and desorption processes of methanol oxidation products on the surface of Pt/C3N4, significantly altering the reaction pathways in photocatalytic methanol conversion process. Guided by these discoveries, a photothermal‐assisted photocatalytic system is designed to achieve a high solar‐to‐hydrogen (STH) conversion efficiency of 2.3 %, which is among the highest values reported. This work highlights the important roles of solvents in controlling the adsorption/desorption behaviours of liquid‐phase heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The design of molecular scaffolds bearing multiple functional groups for the activation and ring‐opening of epoxides is a crucial challenge for the synthesis of efficient homogeneous and heterogeneous catalysts that are used for the cycloaddition reaction of CO2 to epoxides. Traditional approaches to prepare such multifunctional catalysts often imply multistep synthetic procedures and expensive building blocks. In this work we show that bifunctional catalysts for the cycloaddition of CO2 to epoxides bearing a Lewis acid metal and a quaternary ammonium halide group can be prepared in just two steps starting from an opportunely designed epoxide precursor by using inexpensive substrates. Such a readily accessible catalyst was applied for the cycloaddition of CO2 to a series of epoxides under atmospheric conditions generally leading to quantitative substrate conversion and high carbonate selectivities. Importantly, we also show that the epoxide‐driven concept developed for the preparation of the molecular catalyst, could be applied to prepare recyclable heterogeneous systems for the target cycloaddition reaction. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation of nitroarenes is a type of important reaction to get corresponding amines, the development of catalysts with outstanding catalytic performance is in urgent need. In this review, we summarize the breakthroughs in the development of supported metal catalysts in the past few decades, including the use of different metals and supports, improved metal utilization efficiency, adjustment of the structure, and the interaction. We focus on how to develop and innovate the structure of the catalyst, aiming at the contradiction between conversion and selectivity in selective hydrogenation of nitroarenes, from the perspective of the structure and the interaction to construct a kind of catalyst with low noble metal loading and high activity, stabilize the active components, and design and fabricate hybrid nanostructured catalysts with desired activity and selectivity. The development process and the catalytic performance of metal‐2D semiconductor hybrid nano‐structure catalyst are also discussed and provide a theoretical and practical basis for the precise design of supported metal catalysts. [ABSTRACT FROM AUTHOR]

The selective oxidation of 5‐(Hydroxymethyl)furfural (HMF) to 2,5‐Furandicarboxylic acid (FDCA) is highly attractive for the production of renewable monomers as substitute for fossil‐based monomers. To achieve a sustainable synthesis, we report on advances for a base‐free approach, reducing waste from the process, using air as oxidant and heterogeneous catalysts. Various Carbon‐based supports, which can be bio‐sourced and cost‐efficient, for Pt particles were investigated as they allow for an easy reuse and at the end‐of‐life Pt can be recycled to enable a closed cycle. Commercially available supports with varying properties, which might replace the base, were studied with Pt particles of similar size and loading. Significant differences in the catalytic activity were observed, which were correlated with the O‐functionalities and graphitization degree of the supports derived from Raman spectroscopy, temperature‐programmed desorption, and X‐ray photoelectron spectroscopy. An activated carbon (Norit ROX) rich in quinone/pyrone‐type groups and a carbon black‐based catalyst with graphene‐layers pushed the efficiency with enhanced FDCA‐yields enabling the complete substitution of the homogeneous base. This allows to circumvent the base in this process which together with high selectivity, air as oxidant, a reusable catalyst, and the use of bio‐based feedstock contributes to the sustainability of the production of renewable monomers. [ABSTRACT FROM AUTHOR]

A fundamental understanding of the exact structural characteristics and reaction mechanisms of interface active sites is vital to engineering an energetic metal–support boundary in heterogeneous catalysis. Herein, benefiting from a newly developed high-temperature ion trap reactor, the reverse water–gas shift (RWGS) (CO2 + H2 → CO + H2O) catalyzed by a series of compositionally and structurally well-defined RhnVO3,4− (n = 3–7) clusters were identified under variable temperatures (298–773 K). It is discovered that the Rh5–7VO3,4− clusters can function more effectively to drive RWGS at relatively low temperatures. The experimentally observed size-dependent catalytic behavior was rationalized by quantum-chemical calculations; the framework of RhnVO3,4− is constructed by depositing the Rhn clusters on the VO3,4 "support", and a sandwiched base–acid–base [Rhout−–Rhin+–VO3,4−; Rhout and Rhin represent the outer and inner Rh atoms, respectively] feature in Rh5–7VO3,4− governs the adsorption and activation of reactants as well as the facile desorption of the products. In contrast, isolated Rh5–7− clusters without the electronic modification of the VO3,4 "support" can only catalyze RWGS under relatively high-temperature conditions. [ABSTRACT FROM AUTHOR]

The selective oxidation of alcohols has drawn significant attention in heterogeneous catalysis with the increasing use of Pickering interfacial catalysis (PIC) for green transformations of alcohols. However, it is still highly desirable to design and develop a solid catalyst with easy separation and recycling, made from abundant resources through a simple synthesis route, for the selective oxidation of alcohols. In this study, ferrite nanoparticles, synthesized via a hydrothermal process, were employed to act as a stabilizer and catalyst in PIC for the oxidation of benzyl alcohol using H2O2. The ferrite nanoparticles exhibited higher catalytic performance in PIC than in acetonitrile. The turnover number (TON) of the nanocatalyst in PIC was found to be 1.5–4 times higher than that in acetonitrile, and the reaction constant in PIC (kPIC = 0.712 h−1) was almost twice that in acetonitrile (kCH3CN = 0.310 h−1) for MnFe2O4 nanoparticles. Moreover, other alcohols could also be oxidized with moderately high conversion and selectivity in PIC. Significantly, the ferrite nanocatalyst could be easily separated from PIC using a magnet for reuse, achieving 88% BzOH conversion after five cycles. The use of hazardous organic solvents was avoided in PIC, making it a more advanced, green and sustainable reaction system. [ABSTRACT FROM AUTHOR]

This article explores the functionalization of single-walled carbon nanotubes (SWCNTs) through covalent chemical transformations. The authors focus on the Prato reaction and the use of azomethine ylides as intermediates. They investigate different reaction conditions and heating methods to optimize the process. The study also examines the application of an iridium-supported catalyst for the reduction of acetophenone. The findings provide valuable insights into the potential applications of SWCNTs in electronics, biosensors, energy storage, and medicine. Additionally, the study discusses the use of imino esters for functionalizing SWCNTs and the successful preparation of a heterogeneous catalyst using the functionalized SWCNTs as a metal support. The catalyst showed high efficiency in catalyzing the Meerwein-Ponndorf-Verley reduction of acetophenone. The study also highlights the advantages of microwave-assisted heating and the potential industrial applications of the supported catalyst. [Extracted from the article]

Immobilized Pd‐catalyzed Suzuki‐Miyaura coupling under continuous‐flow conditions using a packed‐bed reactor, representing an efficient, automated, practical, and safe technology compared to conventional batch‐type reactions. The core objective of this study is the development of an active and durable catalyst. In contrast to supported Pd nanoparticles, the attachment of Pd complexes onto solid supports through well‐defined coordination sites is considered a favorable approach for preparing highly dispersed and stabilized Pd species. These species can be directly employed in various flow reactions without the need for pre‐treatment. This concept paper explores recent achievements involving the application of immobilized Pd complexes as precatalysts for continuous‐flow Suzuki‐Miyaura coupling. Our focus is to elucidate the significance of the designed catalyst structures in relation to their catalytic performance under flow conditions. Additionally, we highlight various reaction systems and catalyst packing methods, emphasizing their crucial roles in establishing a practical synthesis process. [ABSTRACT FROM AUTHOR]

Within the realm of organic synthesis, photocatalysis has blossomed since the beginning of the last decade. A plethora of classical reactivities, such as selective oxidation of alcohol and amines, redox radical formation of reactive species in situ, and indirect activation of an organic substrate for cycloaddition by EnT, have been revised in a milder and more sustainable fashion via photocatalysis. However, even though the spark of creativity leads scientists to explore new reactions and reactivities, the urgency of replacing the toxic and critical metals that are involved as catalysts has encouraged chemists to find alternatives in the branch of science called organocatalysis. Unfortunately, replacing metal catalysts with organic analogues can be too expensive sometimes; however, this drawback can be solved by the reutilization of the catalyst if it is heterogeneous. The aim of this review is to present the recent works in the field of heterogeneous photocatalysis, applied to organic synthesis, enabled by continuous flow. In detail, among the heterogeneous catalysts, g-CN, polymeric photoactive materials, and supported molecular catalysts have been discussed within their specific sections, rather than focusing on the types of reactions. [ABSTRACT FROM AUTHOR]

Bimetallic PtRu/C catalysts have been prepared by depositing Ru onto a commercial Pt/C catalyst and subsequent thermal annealing. Different Pt : Ru ratios of 1 : 1, 2 : 1, 4 : 1, 8 : 1, and 16 : 1 have been investigated with annealing temperatures of 350 and 500 °C. Using X‐ray diffraction (XRD), synchrotron powder X‐ray diffraction (SPXRD) combined with pair distribution function (PDF) analysis and scanning transmission electron microscopy with energy dispersive X‐ray spectrum imaging (STEM‐EDXS), we show that diffusion of Ru into the fcc crystal structure of the Pt nanoparticles takes place during thermal annealing. Partial segregation and the formation of Pt nanoclusters on the bimetallic surface was observed depending on the Pt : Ru ratio. The annealing process does not only cause a high Pt dispersion but also affects the electronic structure of the Pt surface by broadening the d‐band thus facilitating the product's desorption from the surface of the bimetallic particle. These beneficial effects have been exemplified for the catalytic dehydrogenation of dicyclohexylmethanol, a promising hydrogen carrier compound with 7.2 wt% hydrogen capacity. The most active catalyst material among the tested supported alloys and monometallic reference materials was Pt4Ru1/C after annealing at 500 °C, which increased the hydrogen release productivity by 65 % compared to the unmodified Pt/C catalyst. [ABSTRACT FROM AUTHOR]

Metal‐phenolic networks (MPNs) are a promising platform for developing new heterogeneous catalytic materials for water splitting technologies. This study systematically investigates the relationship between MPN composition and catalytic properties via electropolymerization of copper and cobalt combined with lignin, tannic acid, epigallocatechin‐3‐gallate (EGCG), and gallic acid polyphenols. We find that the choice of metal, size of polyphenol, and polymerization method have the greatest impact on the propensity of MPNs for catalyzing hydrogen evolution. For example, gallic acid‐based MPNs result in smoother surfaces with ~2 nm roughness, resulting in low surface area and lower average current densities compared to all other polyphenols tested. Cobalt‐based MPNs show higher current densities compared to copper, yet higher onset potentials. The results provide a map of design choices that can be used to increase the catalytic performance of new materials used in water electrolysis. [ABSTRACT FROM AUTHOR]

In this work, generalized (2D-COS) and perturbation-correlation moving window (PCMW2D) two-dimensional correlation analyses were applied on a set of hydration-dependent Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance Geometry (FTIR-ATR) data of cellulose nano-sponges (CNSs) consisting of TEMPO-oxidized cellulose nanofibrils (TOCNF) as three-dimensional scaffolds, and branched polyethyleneimine (bPEI) as cross-linker. The aim was to get insights, starting from the computation of synchronous (SCMs) and asynchronous (ACMs) 2D-COS and PCMW2D correlation maps, into the effect of hydration on the hydrogen bond (H-bond) dynamics of water molecules closely attached to the cellulose nanofibrils (interfacial water), based on the assessment of the complex sequence of events affecting the O–H modes of the CNS material at different bPEI:TOCNF (w/w) ratios. The possibility to highlight the time-dependent dynamical evolution exhibited by complex cellulose-based materials, not accessible through conventional 1D FTIR-ATR analysis, can provide useful notions for the development and optimization of CNSs-based devices for different applications, including water remediation, drug-delivery and heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

A novel and efficient procedure has been developed to synthesize furan‐2‐carboxylate derivatives through a one‐pot condensation of chloroacetate derivatives, 1,3‐diketones, and chloroform in the presence of magnetic sodium aluminate 40 wt. % (Aluminate NP‐40). The synthesized heterogeneous catalyst can be easily recovered from the reaction mixture by applying an external magnetic field. Magnetic aluminate NP catalysts provide a sustainable, environmentally friendly, and cost‐effective method for synthesizing furan‐2‐carboxylate derivatives. Additionally, the catalyst is stable and can be reused multiple times without losing its catalytic properties. High product yields in a short experimental time and easy workup are other advantages of the present method. All synthesized compounds were characterized by NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The hydrogenolysis of oxygenates such as alcohols and ethers is central to the biomass valorization and also a valuable transformation in organic synthesis. However, a mild and efficient catalyst system for the hydrogenolysis of a large variety of alcohols and ethers with various functional groups is still underdeveloped. Here, we report an aluminum metaphosphate‐supported Pt nanoparticles (Pt/Al(PO3)3) for the hydrogenolysis of a wide variety of primary, secondary, and tertiary alkyl and benzylic alcohols, and dialkyl, aryl alkyl, and diaryl ethers, including biomass‐derived furanic compounds, under mild conditions (0.1–1 atm of H2, as low as 70 °C). Mechanistic studies suggested that H2 induces formation of the surface Brønsted acid sites via its cleavage by supported Pt nanoparticles. Accordingly, the high efficiency and the wide applicability of the catalyst system are attributed to the activation and cleavage of C−O bonds by the hydrogen‐induced Brønsted acid sites with the assistance of Lewis acidic Al sites on the catalyst surface. The high efficiency of the catalyst implies its potential application in energy‐efficient biomass valorization or fine chemical synthesis. [ABSTRACT FROM AUTHOR]

Bimetallic catalysts combining precious and earth-abundant metals in well designed nanoparticle architectures can enable cost efficient and stable heterogeneous catalysis. Here, we present an interaction-driven in-situ approach to engineer finely dispersed Ni decorated Pt nanoparticles (1-6 nm) on perovskite nanofibres via reduction at high temperatures (600-800 oC). Deposition of Pt (0.5 wt%) enhances the reducibility of the perovskite support and promotes the nucleation of Ni cations via metal-support interaction, thereafter the Ni species react with Pt forming alloy nanoparticles, with the combined processes yielding smaller nanoparticles that either of the contributing processes. Tuneable uniform Pt-Ni nanoparticles are produced on the perovskite surface, yielding reactivity and stability surpassing 1 wt.% Pt/γ-Al2O3 catalysts for CO oxidation. This approach heralds the possibility of in-situ fabrication of supported bimetallic nanoparticles with engineered compositional distributions and performance. Utilizing "Chemistry at a point", Ni is exsolved from a perovskite lattice under deposited Pt nanoparticles. This yields even smaller Ni Pt alloy nanoparticles on a perovskite nanofiber structure, exhibiting high catalytic activity. [ABSTRACT FROM AUTHOR]

Stereoselective hydrogenation of tetrasubstituted olefins is an attractive method to access compounds with two contiguous stereocenters. However, homogeneous catalysts for enantio‐ and diastereoselective hydrogenation exhibit low reactivity toward tetrasubstituted olefins due to steric crowding between the ligand scaffold and the substrate. Monometallic heterogeneous catalysts, on the other hand, provide accessible surface active sites for hindered olefins but exhibit unpredictable and inconsistent stereoinduction. In this work, we develop a Pt−Ni bimetallic alloy catalyst that can diastereoselectively hydrogenate unactivated, sterically‐bulky tetrasubstituted olefins, utilizing the more oxophilic Ni atoms to adsorb a hydroxyl directing group and direct facially‐selective hydrogen addition to the olefin via the Pt atoms. Structure‐activity studies on several Pt−Ni compositions underscore the importance of exposing a uniform PtNi alloy surface to achieve high diastereoselectivity and minimize side reactions. The optimized Pt−Ni/SiO2 catalyst exhibits good functional group tolerance and broad scope for tetrasubstituted olefins in a cyclopentene scaffold, generating cyclopentanol products with three contiguous stereocenters. The synthetic utility of the method is demonstrated in a four‐step synthesis of (1R,2S)‐(+)‐cis‐methyldihydrojasmonate with high yield and enantiopurity. [ABSTRACT FROM AUTHOR]

Phenylacetaldehyde (PhA) is an aromatic aldehyde which has a hyacinth‐like floral, sweet and green‐leafy odour. PhA is used as a perfumery chemical and a rate‐controlling additive in cosmeceutical and polymer industries, respectively. The conventional process of PhA manufacturing in industries involve hazardous and costly feedstock and often lead to generation of substantial amount of waste. Moreover, usage of stoichiometric reagents often makes the processes economically impractical. This article illustrates the possibility of production of PhA from low‐cost feedstock styrene through a single‐step, one‐pot method wherein various metal oxides have been utilized as catalysts for styrene oxidation under the influence of cumene hydroperoxide (CHP). Ag2O is found to be the highest PhA‐yielding catalyst and a promising candidate for scaling up for its considerably good reusability up to 6 consecutive uses. A maximum of ~45% PhA selectivity has been observed at ~60% styrene conversion. Interestingly, this process does not require any alkaline/acid wash and hence does not produce any organic/inorganic liquid effluent stream. Furthermore, all the major byproducts found, that is styrene oxide, benzaldehyde and acetophenone, are themselves considered as valorized styrene derivatives. Overall, the metal oxide catalysed styrene oxidation has potential to take over the conventional industrial process(es) for sustainable selective production of PhA Along with a plausible mechanism of styrene oxidation over Ag2O, a conceptualized reaction–separation framework has been reported for intensified production of PhA from CHP‐based styrene oxidation. [ABSTRACT FROM AUTHOR]

Selective and efficient transformation of lignin to the value‐added chemicals is of importance to realize the industrial application of the renewable biomass resources. The oxidative cleavage of carbon‐carbon (C−C) bond is a promising technique for the depolymerization and refining of lignin. Herein, the catalyst system for oxidative valorization of lignin and lignin models is summarized, which includes the thermocatalytic, photocatalytic and electrocatalytic approaches. In the thermocatalytic system, homogeneous catalysis and heterogeneous catalysis is introduced and discussed, respectively. For the photocatalytic or electrocatalytic system, the used photocatalyst or electrocatalyst is emphasized. At last, the insights to main challenges and future perspectives on the oxidative valorization of lignin have been presented. [ABSTRACT FROM AUTHOR]

Nowadays, emerging nanocatalysts have gained much attention in the field of organic transformations for the development of greener chemistry protocols. Also, the Biginelli reaction has gained prominence amidst multicomponent reactions due to the extensive therapeutic significance of the product dihydropyrimidinones (DHPMs). In this work, first-time zinc chromite nanoparticles (ZnCr2O4 NPs) were prepared using cow urine (CoU) as a natural source through a biogenic approach. The physicochemical traits of the synthesized ZnCr2O4 NPs were investigated via XRD, UV-DRS, IR, FESEM, EDX, HRTEM, and XPS techniques. Furthermore, ZnCr2O4 NPs were implemented as a heterogeneous nanocatalyst for sustainable, uncomplicated, and one-pot synthesis of DHPM analogs. The synthetic strategy offers diverse appealing attributes, such as simplicity, bland reaction systems, facile work-up, reusability of catalyst, and excellent yield. Being heterogeneous, the nanocatalyst was simply retrieved after the reaction and reused (up to 5 cycles) in the Biginelli reaction without any noticeable diminishment in catalytic performance. As a result, the current study reveals that creating ZnCr2O4 NPs through a simple green approach and evaluating excellent catalytic activity may aid nanochemistry research by opening up new pathways for advanced organic transformations. [ABSTRACT FROM AUTHOR]

The phenomenon of strong metal‐support interaction (SMSI) observed in supported metal catalysts, usually accompanied by the formation of the encapsulation layer on metal nanoparticles, has attracted extensive research attention due to its significance in heterogeneous catalysis. Notably, great progress has been made in recent years in investigating SMSI by in situ transmission electron microscopy (TEM), along with an enhanced comprehension of the underlying mechanisms governing SMSI formation. This emerging topic summarizes recent progress utilizing in situ TEM to study the interaction between metal and support and the relationship between the structure and performance of the supported catalyst under reaction conditions. A brief perspective about the use of in situ TEM for further study of SMSI is also presented, showing prospects in this field that will stimulate further upsurging research in promoting the catalytic efficiency of supported catalysts. [ABSTRACT FROM AUTHOR]

A set of graphitic carbon nitride samples was prepared using a straightforward experimental procedure without templates and any subsequent treatments. The materials were studied in‐depth using a range of physical and chemical methods such as X‐ray diffraction, FTIR spectroscopy, elemental analysis (CHN), nitrogen physisorption, SEM, XPS, TPD CO2. The resulting g‐C3N4 was shown to be highly efficient in carboxymethylation of cinnamyl alcohol with dimethyl carbonate yielding up to ca. 82 % of the desired cinnamyl methyl carbonate. In the studied conditions, an increase in the surface N atomic content leads to an increase in selectivity towards the desired carbonate, while a higher surface O content was beneficial for side products. Metal‐free graphitic carbon nitride was shown to be one of the most productive (ca. 2 mol/h kgcat) in the investigated reaction among studied heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

To inhibit the deep conversion of partial oxidation products (POX-products) in C-H bonds' functionalization utilizing O2, 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin cobalt(II) and 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin copper(II) were immobilized on the surface of hybrid silica to conduct relay catalysis on the surface. Fluorocarbons with low polarity and heterogeneous catalysis were devised to decrease the convenient accessibility of polar POX-products to catalytic centers on the lower polar surface. Relay catalysis between Co and Cu was designed to utilize the oxidation intermediates alkyl hydroperoxides to transform more C-H bonds. Systematic characterizations were conducted to investigate the structure of catalytic materials and confirm their successful syntheses. Applied to C-H bond oxidation, not only deep conversion of POX-products was inhibited but also substrate conversion and POX-product selectivity were improved simultaneously. For cyclohexane oxidation, conversion was improved from 3.87% to 5.27% with selectivity from 84.8% to 92.3%, which was mainly attributed to the relay catalysis on the surface excluding products. The effects of the catalytic materials, product exclusion, relay catalysis, kinetic study, substrate scope, and reaction mechanism were also investigated. To our knowledge, a practical and novel strategy was presented to inhibit the deep conversion of POX-products and to achieve efficient and accurate oxidative functionalization of hydrocarbons. Also, a valuable protocol was provided to avoid over-reaction in other chemical transformations requiring high selectivity. [ABSTRACT FROM AUTHOR]

Heterogenization of Eosin Y by 3D‐printing and its application in photocatalysis are reported. The approach allows a fine tuning of the photocatalyst morphology and its rapid preparation. Photocatalytic activity was evaluated through model organic reactions involving oxidation, reduction, and photosensitization pathways. The efficiency, recyclability and stability of 3D printed EY is remarkable paving the way to new generation of heterogeneous photocatalysts with a perfect control of their shape and adaptable to any photoreactors. [ABSTRACT FROM AUTHOR]

Colloidal and supported manganese nanoparticles were synthesized following an organometallic approach and applied in the catalytic transfer hydrogenation (CTH) of aldehydes and ketones. Reaction parameters for the preparation of colloidal nanoparticles (NPs) were optimized to yield small (2–2.5 nm) and well‐dispersed NPs. Manganese NPs were further immobilized on an imidazolium‐based supported ionic phase (SILP) and characterized to evaluate NP size, metal loading, and oxidation states. Oxidation of the Mn NPs by the support was observed resulting in an average formal oxidation state of +2.5. The MnOx@SILP material showed promising performance in the CTH of aldehydes and ketones using 2‐propanol as a hydrogen donor, outperforming previously reported Mn NPs‐based CTH catalysts in terms of metal loading‐normalized turnover numbers. Interestingly, MnOx@SILP were found to lose activity upon air exposure, which correlates with an additional increase in the average oxidation state of Mn as revealed by X‐ray absorption spectroscopic studies. [ABSTRACT FROM AUTHOR]

Hyperpolarized 129Xe gas was FDA‐approved as an inhalable contrast agent for magnetic resonance imaging of a wide range of pulmonary diseases in December 2022. Despite the remarkable success in clinical research settings, the widespread clinical translation of HP 129Xe gas faces two critical challenges: the high cost of the relatively low‐throughput hyperpolarization equipment and the lack of 129Xe imaging capability on clinical MRI scanners, which have narrow‐bandwidth electronics designed only for proton (1H) imaging. To solve this translational grand challenge of gaseous hyperpolarized MRI contrast agents, here we demonstrate the utility of batch‐mode production of proton‐hyperpolarized diethyl ether gas via heterogeneous pairwise addition of parahydrogen to ethyl vinyl ether. An approximately 0.1‐liter bolus of hyperpolarized diethyl ether gas was produced in 1 second and injected in excised rabbit lungs. Lung ventilation imaging was performed using sub‐second 2D MRI with up to 2×2 mm2 in‐plane resolution using a clinical 0.35 T MRI scanner without any modifications. This feasibility demonstration paves the way for the use of inhalable diethyl ether as a gaseous contrast agent for pulmonary MRI applications using any clinical MRI scanner. [ABSTRACT FROM AUTHOR]

Copper-catalyzed azide–alkyne cycloaddition click (CuAAC) reaction is widely used to synthesize drug candidates and other biomolecule classes. Homogeneous catalysts, which consist of copper coordinated to a ligand framework, have been optimized for high yield and specificity of the CuAAC reaction, but CuAAC reaction with these catalysts requires the addition of a reducing agent and basic conditions, which can complicate some of the desired syntheses. Additionally, removing copper from the synthesized CuAAC-containing biomolecule is necessary for biological applications but inconvenient and requires additional purification steps. We describe here the design and synthesis of a PNN-type pincer ligand complex with copper (I) that stabilizes the copper (I) and, therefore, can act as a CuAAC catalyst without a reducing agent and base under physiologically relevant conditions. This complex was immobilized on two types of resin, and one of the immobilized catalyst forms worked well under aqueous physiological conditions. Minimal copper leaching was observed from the immobilized catalyst, which allowed its use in multiple reaction cycles without the addition of any reducing agent or base and without recharging with copper ion. The mechanism of the catalytic cycle was rationalized by density functional theory (DFT). This catalyst's utility was demonstrated by synthesizing coumarin derivatives of small molecules such as ferrocene and sugar. [ABSTRACT FROM AUTHOR]

The layered double hydroxides (LDHs) of transition metals are of great interest as building blocks for the creation of composite photocatalytic materials for hydrogen production, environmental remediation and other applications. However, the synthesis of most LDHs is reported only by the conventional coprecipitation method, which makes it difficult to control the catalyst's crystallinity. In the present study, ZnCr- and NiCr-LDHs have been successfully prepared using a facile hydrothermal approach. Varying the hydrothermal synthesis conditions allowed us to obtain target products with a controllable crystallite size in the range of 2–26 nm and a specific surface area of 45–83 m2∙g−1. The LDHs synthesized were investigated as photocatalysts of hydrogen generation from aqueous methanol. It was revealed that the photocatalytic activity of ZnCr-LDH samples grows monotonically with the increase in their average crystallite size, while that of NiCr-LDH ones reaches a maximum with intermediate-sized crystallites and then decreases due to the specific surface area reduction. The concentration dependence of the hydrogen evolution activity is generally consistent with the standard Langmuir–Hinshelwood model for heterogeneous catalysis. At a methanol content of 50 mol. %, the rate of hydrogen generation over ZnCr- and NiCr-LDHs reaches 88 and 41 μmol∙h−1∙g−1, respectively. The hydrothermally synthesized LDHs with enhanced crystallinity may be of interest for further fabrication of their nanosheets being promising components of new composite photocatalysts. [ABSTRACT FROM AUTHOR]

The development of novel bio-based heterogeneous catalytic systems with easy separation and recyclability is significant in chemical synthesis. In this work, palladium nanoparticles have been successfully anchored onto the surface of MnO2 modified cotton fabric via a facile method for synthesizing Pd(0)@MnO2–CF catalyst. Several characterization methods, including field emission gun scanning electron microscopy (FEG-SEM), energy-dispersive X-ray electron microscopy (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron microscopy (XPS), were used to confirm the immobilization of palladium nanoparticles on to the cotton fabric. The catalytic activity of the synthesized catalyst, Pd(0)@MnO2–CF, was evaluated for oxidation of alcohols, oxidative deprotection of oximes and degradation of methyl orange, for which the catalyst demonstrated good activity and selectivity. The developed catalyst is easy to handle and can be separated from the reaction mixture using laboratory tweezers. It eliminates the need to employ other tedious work-up procedures. Further, the reusability of Pd(0)@MnO2–CF was studied by performing oxidation of 4-bromobenzyl alcohol and oxidative deprotection of 4-bromobenzaldehyde oxime consecutively five times, and a minor loss in catalytic activity was observed suggesting high stability of the developed catalyst. [ABSTRACT FROM AUTHOR]

Chemical recycling and upcycling offer promising approaches for the management of plastic wastes. Hydrodeoxygenation (HDO) is one of the appealing ways for conversion of oxygen‐containing plastic wastes, including polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), polyphenyl ether (PPO), and polyether ether ketone (PEEK), into cyclic alkanes and aromatics in high yields under mild reaction conditions. The challenge lies in achieving C−O activation while preserving C−C bonds. In this review, we highlight the recent advancements in catalytic strategies and catalysts for the conversion of these oxygen‐containing plastic wastes into cycloalkanes and aromatics. The reaction systems, including multi‐step routes, direct HDO and transfer HDO methods, are exemplified. The design and performance of HDO catalysts are systematically summarized and compared. We comprehensively discuss the functions of the catalysts’ components, reaction pathway and mechanism to gain insights into the HDO process for efficient valorization of oxygen‐containing plastic wastes. Finally, we provide perspectives for this field, with specific emphasis on the non‐noble metal catalyst design, selectivity control, reaction network and mechanism studies, mixed plastic wastes management and product functionalization. We anticipate that this review will inspire innovations on the catalytic process development and rational catalyst design for the HDO of oxygen‐containing aromatic plastics to establish a low‐emission circular economy. [ABSTRACT FROM AUTHOR]

Copper nanoparticles (Cu‐NPs) have garnered substantial interest in the field of nanotechnology due to their exceptional physical and chemical properties and cost‐effectiveness. However, challenges such as particle aggregation and rapid copper oxidation affect nanoscale production. This study systematically investigates the synthesis of colloidal Cu‐NPs using chitosan (Cts) as a stabilizer and reducing agent in the arc discharge system, comparing it to distilled water as a medium. Confirmation of the purity, size, and morphology of the Cu‐NPs is achieved through various physicochemical characterization methods. X‐ray diffraction patterns confirm the synthesis of highly pure face‐centered cubic (fcc) crystal Cu‐NPs. UV–vis analysis reveals absorption peaks at 572–585 nm, indicating pure copper. Fourier‐transform infrared spectroscopy shows peaks at 638 and 597 cm−1, corresponding to Cu─Cts bonds. Transmission electron microscopy images depict spherical nanoparticles ranging from 15 to 45 nm, with smaller sizes at higher Cts concentrations. The catalytic activity of Cu‐NPs in the degradation of 4‐nitrophenol to 4‐aminophenol is assessed, with Cu‐NPs synthesized in distilled water demonstrating superior catalytic properties compared to 0.10 wt.% Cts. This study highlights the efficacy of the arc discharge method in producing pure, uniformly sized Cu‐NPs with potential applications in catalysis. [ABSTRACT FROM AUTHOR]

Tuning the crystal phase of alloy nanocrystals (NCs) offers an alternative way to improve their electrocatalytic performance, but, how heterometals diffuse and form ordered‐phase remains unclear. Herein, for the first time, the mechanism for forming tetrametallic ordered‐phase nanoplates (NPLs) is unraveled. The observations reveal that the intermetallic ordered‐phase nucleates through crystallinity alteration of the seeds and then propagates by reentrant grooves. Notably, the reentrant grooves act as intermediate NCs for ordered‐phase, eventually forming intermetallic PdCuIrCo NPLs. These NPLs substantially outperform for oxygen evolution reaction (221 mV at 10 mA cm−2) and hydrogen evolution reaction (19 mV at 10 mA cm−2) compared to commercial Ir/C and Pd/C catalysts in acidic media. For OER at 1.53 V versus RHE, the PdCuIrCo/C exhibits an enhanced mass activity of 9.8 A mg−1Pd+Ir (about ten times higher) than Ir/C. For HER at ‐0. 2 V versus RHE, PdCuIrCo/C shows a remarkable mass activity of 1.06 A mg−1Pd+Ir, which is three‐fold relative to Pd/C. These improvements can be ascribed to the intermetallic ordered‐structure with high‐valence Ir sites and tensile‐strain. This approach enabled the realization of a previously unobserved mechanism for ordered‐phase NCs. Therefore, this strategy of making ordered‐phase NPLs can be used in diverse heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Fine chemicals are produced in small annual volume batch processes (often <10,000 tonnes per year), with a high associated price (usually >USD 10/kg). As a result of their usage in the production of speciality chemicals, in areas including agrochemicals, fragrances, and pharmaceuticals, the need for them will remain high for the foreseeable future. This review article assesses current methods used to produce fine chemicals with heterogeneous catalysts, including both well-established and newer experimental methods. A wide range of methods, utilising microporous and mesoporous catalysts, has been explored, including their preparation and modification before use in industry. Their potential drawbacks and benefits have been analysed, with their feasibility compared to newer, recently emerging catalysts. The field of heterogeneous catalysis for fine chemical production is a dynamic and ever-changing area of research. This deeper insight into catalytic behaviour and material properties will produce more efficient, selective, and sustainable processes in the fine chemical industry. The findings from this article will provide an excellent foundation for further exploration and a critical review in the field of fine chemical production using micro- and mesoporous heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Biodiesel stands out as a promising contender in the quest for renewable energy solutions, offering a greener alternative to traditional fossil fuels. Derived primarily from the transesterification of vegetable oils or animal fats, biodiesel offers an eco-friendly energy avenue with a minimized carbon footprint. Catalysts are central to the success of this process, which significantly enhance yield rates. Geopolymers, traditionally associated with construction applications due to their inorganic nature, have been derived from aluminosilicate sources activated using alkaline solutions. However, recent advancements spotlight geopolymers in a new light, emphasizing their prospective role as nanocatalytic agents for biodiesel synthesis. This paradigm shift suggests improved production efficiency and an innovative method of repurposing industrial waste. This study centers on the pioneering application of geopolymers, fortified with magnetite, as potent heterogeneous catalysts for biodiesel generation from soybean and safflower oils. By leveraging a meticulously crafted geopolymer matrix—consisting of metakaolin, sodium hydroxide, and magnetite—this research replaced traditional catalysts with this advanced nanostructured geopolymer variant in the biodiesel methylation process. The research delved deep to ascertain the prime synthesis conditions. Furthermore, utilizing cutting-edge machine learning methodologies provided an analytical lens to navigate the extensive experimental data, thereby fine-tuning the optimization trajectory. One of the salient takeaways from this research is the validation that geopolymer catalysts, rooted in kaolinite, can be ingeniously tailored to ensure elevated biodiesel yields across a spectrum of oil sources, underscoring their unparalleled efficiency and versatility in the biofuel domain. [ABSTRACT FROM AUTHOR]

We improved our previous theoretical method for prediction of the catalytic activity of porous materials, which is based on the concept of transition state shape selectivity. This method used adsorption energy calculations for transition state (TS) with «frozen» (only the placement of TS inside the pore is optimized) structure on porous materials with molecular mechanics (MM) as a calculational method. Our improvement consists of application of semi-empirical methods with dispersion correction (e.g., PM3-D3 or PM6-D3H4) instead of MM. We found that with semi-empirical methods adsorption energy dependences on pore diameter are similar to dependences obtained by MM, and also semi-empirical methods predict the same value of the cavity diameter, at which there is a maximum of TS adsorption energy. Despite these similarities in obtained results, semi-empirical methods have the advantages that they can more accurately describe structures, intermolecular interactions and energy values. We have shown that the level of theory (PM3-D3 or RI-MP2/ma-def2-SVP) used for TS structure search, in the case of suggested method, has little effect. [ABSTRACT FROM AUTHOR]

Experimental and theoretical insights into robust PIL-Br@ZIF-8 hetero-frameworks for the selective conversion of CO 2 into cyclic carbonates under mild conditions. [Display omitted] • A novel strategy is developed for fabricating core–shell PILs@ZIF-8 composites. • PIL-Br@ZIF-8 enables simultaneous adsorption and activation of CO 2 and epoxide. • Low-concentration/low-pressure CO 2 conversion into cyclic carbonates was achieved. • PIL-Br@ZIF-8 is recyclable and exhibits good thermal and structural stability. • Valuable insight into the cycloaddition mechanism is theoretically elucidated. The present study, for the first time, reports the fabrication of core–shell poly(ionic liquids)@ZIF-8 nanocomposites through a facile in-situ polymerization strategy. These composites exhibited exceptional structural characteristics including high specific surface areas and the integration of high-density Lewis acid/base and nucleophilic active sites. The structure–activity relationship, reusability, and versatility of the poly(ionic liquids)@ZIF-8 composites were investigated for the cycloaddition reaction between CO 2 and epoxide. By optimizing the composites structures and their catalytic performance, PIL-Br@ZIF-8(2:1) was identified as an exciting catalyst that exhibits high activity and selectivity in the synthesis of various cyclic carbonates under mild or even atmospheric pressure or simulated flue gas conditions. Moreover, the catalyst demonstrated excellent structural stability while maintaining its catalytic activity throughout multiple usage cycles. By combining DFT calculations, we investigated the transition states and intermediate geometries of the cycloaddition reaction in different coordination microenvironments, thereby proposing a synergistic catalytic mechanism involving multiple active sites. [ABSTRACT FROM AUTHOR]

Steam reforming of glycerol (GSR) to produce hydrogen has been considered a sustainable and low-cost route for hydrogen production. The selection of a suitable catalyst support is crucial for achieving efficient hydrogen production at lower temperatures. CeO 2 has been widely used in heterogeneous catalysis and exhibits excellent low-temperature catalytic performance. However, different calcination mode may influence catalyst performance. In this study, the Ni/CeO 2 catalyst prepared by rapid calcination mode (Ni/CeO 2 -RC), was used for hydrogen production from GSR, and the Ni/CeO 2 catalyst with the conventional programmed-heating calcination method (Ni/CeO 2 -PC) was applied for comparison. The effect of different calcination modes on the physico-chemical properties of the catalysts was investigated through multiple characterizations such as N 2 adsorption-desorption, X-ray diffraction, hydrogen temperature programmed reduction, transmission electron microscopy, X-ray photoelectron spectroscopy, H 2 chemisorption, CO-oxygen storage capacity and conversion, temperature programmed oxidation, and Raman spectroscopy. The rapid calcination mode promoted stronger metal-support interactions in Ni/CeO 2 -RC, inducing the formation of nickel species highly susceptible to reduction due to the electronic effect. Additionally, rapid calcination facilitated the increased incorporation of nickel particles into the cerium dioxide lattice, leading to lattice distortions, thereby contributing to the formation of more oxygen vacancies. The abundant oxygen vacancies promoted the activation of water, thus realizing the high H 2 selectivity of Ni/CeO 2 -RC. Moreover, the strong oxygen storage-release ability of Ni/CeO 2 -RC facilitated the oxidative effect of carbon deposition and the strong Ni–CeO 2 interaction effectively inhibit sintering of nickel nanoparticles on Ni/CeO 2 -RC. Therefore, Ni/CeO 2 -RC exhibited outstanding catalytic stability, remaining active for 35 h without deactivation, whereas Ni/CeO 2 -PC rapidly deactivated after 25 h of reaction. [Display omitted] • Ni/CeO 2 catalyst with rapid calcination enhances catalytic stability of the catalyst. • Nickel-ceria interaction modulates active nickel and oxygen vacancies. • Strong nickel-ceria interaction is achieved through rapid calcination. • Ni/CeO 2 catalyst with rapid calcination inhibits the formation of carbon deposition. [ABSTRACT FROM AUTHOR]

The social impact assessment (SIA) is considered by the literature to be as important as the assessment of economic impacts, as it allows decision-makers to anticipate the possible social consequences of proposed projects. However, to guide the technology selection process in the context of biorefineries, the evaluation models mostly consider technical, economic, and environmental indicators. The objective of the research is to propose a multicriteria decision model to evaluate the social impact of bioconversion technologies in small- and medium-sized biorefineries. Three phases were considered: (1) technological prospecting, which identified eight bioconversion technologies; (2) application of the SODA method (Strategic Options Development and Analysis), which identified nine basic social criteria; and (3) the PROMETHEE-ROC method, which used the structured model to identify the most appropriate bioconversion technology, considering aspects related to SIA. From a theoretical point of view, the proposed model is the only one to consider in depth the social dimension in decision-making on the adoption of bioconversion technologies. From a managerial point of view, the proposed model allows for optimizing the investment decision process in technologies in the context of small- and medium-sized biorefineries. The results point to the existence of a lack of research aimed at investigating the social aspects of small- and medium-sized biorefineries, which use different technological routes for the production of multiproducts. In addition, the technologies of hydrodynamic cavitation and heterogeneous catalysis are presented as those that can positively impact social issues in territories and consequently generate new business opportunities and healthy living. It is concluded that the absence of an updated and efficient national policy for the development of technologies oriented to the use of biomass, which aim to promote positive social impacts, has caused the impoverishment of communities as well as a proliferation of work analogous to slavery in the different regions of the country. Therefore, the proposed model can be used by decision-makers to simplify the process of evaluating technologies to be used for the bioconversion of raw materials into several high-added-value products in small- and medium-sized biorefineries, as well as to support the implementation of strategies that favor the technological and human development of communities. [ABSTRACT FROM AUTHOR]

To accelerate the practical application of water splitting in alkaline media, it is imperative to enhance the electrocatalytic performance for the Hydrogen Evolution Reaction (HER). In this context, we demonstrate that a simple (one‐pot, one‐step) electrodeposition process of nickel (Ni) in the presence of 3,5‐diamino1,2,4‐triazole (DAT) results in the formation of fractally structured Ni films with a significantly increased surface area. The Electrochemically active surface area (ECSA) increases with the electrodeposition charge passed, with the film electrodeposited at 14 C cm−2 achieving a reduction in overpotential at −10 mA cm−2 (η10) to 65.7 mV, coupled with a remarkable increase in ECSA (114‐fold greater than that of Ni‐foil). Additionally, nickel deposited in the presence of DAT effectively mitigates deactivation during electrolysis, exhibiting a 3.6‐fold lower overpotential degradation compared to that of the smooth Ni foil. This simple electrodeposition technique, applicable to a variety of conductive substrates, is distinguished by its high catalytic performance in the HER, a feature of considerable significance. [ABSTRACT FROM AUTHOR]

Polystyrene plastics present significant environmental and human health threats due to their poor recyclability and degradability. However, leveraging their properties to enhance material performance stands out as one of the most effective strategies for mitigating these issues. Here, we have employed recycled expanded polystyrene plastics to manufacture metal–organic framework/expanded polystyrene plastic composites (MOF@EPP) using an adverse solvent precipitation method. This method simultaneously recycles EPPs and safeguards moisture-sensitive MOFs. Due to the exceptional hydrophobic properties of EPPs, HKUST−1@EPP can maintain structural integrity even when immersed in water for 30 days. This method is applicable to other moisture-sensitive MOFs, such as MOF−74(Zn) and MIL−53(Al). The HKUST−1@EPP composite also exhibits desirable heterogeneous catalytic activity in the Knoevenagel condensation reaction between benzaldehyde and acrylonitrile. The conversion rate can reach 94.9% within 4 h at 90 °C and does not exhibit a significant decrease even after six cycles, even in the presence of water. This study not only introduces a novel concept for recycling polystyrene plastics, but also offers a practical strategy for safeguarding moisture-sensitive MOFs. [ABSTRACT FROM AUTHOR]

The in‐depth study on reduction–specified coupling reactions of the nitroarenes by heterogeneous cobalt catalysis opens a door for diversified syntheses of functional N‐containing molecules. Guided by the structure–function relationship of heterogeneous materials, rational design of nano–catalysts can effectively regulate the routes of organic reactions. Precise transformation of the intermediates generated during the nitroarene reduction with a suitable nano–catalyst is a promising way to develop new tandem reactions, and to synthesize structurally novel compounds that are of difficult access with the conventional approaches. [ABSTRACT FROM AUTHOR]

Adsorption of metal‐organic complexes on metallic surfaces to produce well‐defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans‐effect" a dome‐shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum‐evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl‐ and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods. [ABSTRACT FROM AUTHOR]

The direct conversion of specific C−H bonds to C−Si bonds in alkanes or aromatics via catalytic methods has attracted growing research interest. Herein, we report the preparation of a new iridium catalyst supported on a naphthyridine‐based porous organic polymer and its successful application in the dehydrogenative silylation of 2‐arylphenols or alcohol and hydrosilanes to access ring‐fused oxasilacycles. The synthetic method exhibits broad substrate scope and good functional group compatibility while avoiding the use of hydrogen acceptors. In addition, this organic polymer supported iridium catalyst could be easily recovered from the reaction system and reused for at least seven times without apparent deactivation. This research provides new insights for the further design of heterogeneous nanocatalysts and contributes to the synthesis of silicon‐substituted functional molecules. [ABSTRACT FROM AUTHOR]

In heterogeneous catalysis, heterolytic H2 activation for (selective) hydrogenation and hydroprocessing reactions involves the dissociation of adsorbed H2 molecules into proton (Hδ+) and hydride (Hδ−) on the catalyst surface. This approach offers several advantages, including high selectivity for polar bond (s), a low energy barrier for H2 dissociation, a high capacity for reaction‐favorable H2 adsorption, and reduced catalyst poisoning. This requires the construction of frustrated Lewis pairs on the catalyst surface, satisfying specific criteria, such as having an abundant quantity of Lewis pairs with steric hindrance and maintaining a certain distance of 3–5 Å between the pairs. This review highlights intrinsic catalyst properties for heterolytic H2 activation based on state‐of‐the‐art reports. The main components necessary for this activation include supports with strong basic sites and/or oxygen vacancies, and/or metals of single atom. For this purpose, designed catalytic materials aim to strengthen the Lewis acidity and basicity, improve the polarization of Lewis pairs, enrich oxygen vacancies, maximize the interfacial area between metal species and Lewis base, and enhance metal–support interaction. Therefore, heterogeneous catalysts retaining such heterolytic H2 activation characteristics will be significantly effective in various hydrogenation and hydroprocessing reactions. [ABSTRACT FROM AUTHOR]

Heterogeneous catalysis is the most widely used process for ethylene polymerization in industry. Active site distribution is one of the crucial issues in the heterogeneous catalysis, which strongly influences the catalytic process and the microstructure of synthesized polyethylene. In this respect, aiming at an explicit understanding of the progress, the challenge and the possible future directions in the study of heterogeneous catalysis of ethylene polymerization, the recent strategies of designing heterogeneous catalysts are reviewed from the perspective of tailoring the active site distribution, where the regulation of chain structures, including molecular weight distribution, branch distribution and entanglement state, are highlighted. The in situ and operando characterizations are also reviewed for assisting the understanding of structural information in heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Tetranuclear cores (M−E)2 of transition metals (M) and tetrylenes (EII=Si, Ge, Sn) are key motifs in homogeneous and heterogeneous catalysis. They exhibit a continuum of M−M and E−E bonding within the inorganic core that leads to a variety of structures for which there are no specific synthetic methods. Herein, we report a series of highly reduced [Ni0GeII]2 squares solely stabilized by bulky terphenyl (C6H3−2,6‐Ar2) ligands, for which we provide complementary and high‐yielding syntheses. Reactivity studies with common Lewis bases (carbene and CO) evince that the structure of the (M−E)2 core can be transformed. We have investigated this core modification by computational means, offering a rationale to better understand the continuum of bonding across these clusters. [ABSTRACT FROM AUTHOR]

Adsorption of metal‐organic complexes on metallic surfaces to produce well‐defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans‐effect" a dome‐shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum‐evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl‐ and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods. [ABSTRACT FROM AUTHOR]

The high‐entropy‐alloy (HEA) nanoparticles with four, five or more metals significantly can yield the developments of functional materials with excellent performances in various reactions. However, the underlying reaction mechanisms of heterogeneous catalysis for HEA have been rarely investigated, due to their diverse elements and complex compositions. In this study, we successfully synthesized the homogeneously dispersed Ru−Rh−Pd−Pt HEA with adjustable compositions, as the multiple‐atom‐site catalysts (MASC). In the NOx reduction performance tests, Ru0.4 (Rh0.33Pd0.33Pt0.33)0.6 MASC showed the highest activity, which was significantly improved compared to that of the best monometal Rh, with the light‐off temperature decreasing by ca. 50 °C. The Fourier transform infrared measurements revealed that the outstanding activity of Ru−Rh−Pd−Pt MASC was attributable to the well‐coupled elementary steps of the CO adsorption, NO adsorption, NO dissociation and O spillover on the Ru, Rh, Rh−Pd and Pt sites, respectively, which explained the first clear reaction mechanism in heterogeneous catalysis for HEA. [ABSTRACT FROM AUTHOR]