Catalytic System Research Articles

Combining Two Mechanistically Distinct Reactions from a Single Iron Complex: A Tandem Approach to Thermally Stable and Recyclable Polymers

AbstractA shift from petrochemical feedstocks to renewable resources has the potential to address some of the environmental concerns associated with petrochemical extraction, thereby making the production of plastics a sustainable process. Consequently, there is a growing interest in the development of selective techniques for the conversion of abundant renewable feedstocks into environmentally friendly polymers. We present a one‐pot iron‐based catalytic system, which is active, efficient, and selective under mild conditions for producing of renewable copolymers. We demonstrate that this system can function as a tandem catalyst for the production of poly(silylether)s (PSEs), followed by the ring‐opening polymerization of lactide. This effective approach provides direct access to novel thermally stable copolymers. Furthermore, we detail the quantitative chemical recycling of such copolymers, underscoring their potential as new environmentally friendly materials.

Design and Application of Mesoporous Catalysts for Liquid-Phase Furfural Hydrogenation

Furfural (FAL), a platform molecule derived from biomass through acid-catalyzed processes, holds significant potential for producing various value-added chemicals. Its unique chemical structure, comprising a furan ring and an aldehyde functional group, enables diverse transformation pathways to yield products such as furfuryl alcohol, furan, tetrahydrofuran, and other industrially relevant compounds. Consequently, optimizing catalytic processes for FAL conversion has garnered substantial attention, particularly in selectivity and efficiency. The liquid-phase hydrogenation of FAL has demonstrated advantages, including enhanced catalyst stability and higher product yields. Among the catalysts investigated, mesoporous materials have emerged as promising candidates because of their high surface area, tunable pore structure, and ability to support highly dispersed active sites. These attributes are critical for maximizing the catalytic performance across various reactions, including FAL hydrogenation. This review provides a comprehensive overview of recent advances in mesoporous catalyst design for FAL hydrogenation, focusing on synthesis strategies, metal dispersion control, and structural optimization to enhance catalytic performance. It explores noble metal-based catalysts, particularly highly dispersed Pd systems, as well as transition-metal-based alternatives such as Co-, Cu-, and Ni-based mesoporous catalysts, highlighting their electronic structure, bimetallic interactions, and active site properties. Additionally, metal–organic frameworks are introduced as both catalysts and precursors for thermally derived materials. Finally, key challenges that require further investigation are discussed, including catalyst stability, deactivation mechanisms, strategies to reduce reliance on external hydrogen sources, and the impact of solvent effects on product selectivity. By integrating these insights, this review provides a comprehensive perspective on the development of efficient and sustainable catalytic systems for biomass valorization.

Combining Two Mechanistically Distinct Reactions from a Single Iron Complex: A Tandem Approach to Thermally Stable and Recyclable Polymers.

A shift from petrochemical feedstocks to renewable resources has the potential to address some of the environmental concerns associated with petrochemical extraction, thereby making the production of plastics a sustainable process. Consequently, there is a growing interest in the development of selective techniques for the conversion of abundant renewable feedstocks into environmentally friendly polymers. We present a one-pot iron-based catalytic system, which is active, efficient, and selective under mild conditions for producing of renewable copolymers. We demonstrate that this system can function as a tandem catalyst for the production of poly(silylether)s (PSEs), followed by the ring-opening polymerization of lactide. This effective approach provides direct access to novel thermally stable copolymers. Furthermore, we detail the quantitative chemical recycling of such copolymers, underscoring their potential as new environmentally friendly materials.

Tunable Transfer-Hydrodeoxygenated Upgrading of Lignin-Derived Propylphenols to Versatile Value-Added Alkane-Based Chemicals.

Catalytic refining of lignin holds promise for producing sustainable platform chemicals. In this work, a gaseous hydrogen-free catalytic hydrodeoxygenation system is developed for upgrading lignin-derived phenols to alkane chemicals. Commercially available Raney Ni and HZSM-5 are used as a combinational catalyst, with isopropanol serving as the hydrogen-donating solvent. By modifying the temperature and the ratio of Raney Ni to HZSM-5, the reaction pathways for hydrogenation and deoxygenation can be tailored to specific requirements. As a result, a 97.1% yield of alkane fuels is achieved, with 64.4% propylcyclohexane and 32.7% propylbenzene obtained in one-pot reaction from the hydrodeoxygenation of 2-methoxy-4-propylphenol using a 3:1 mass ratio of Ni to HZSM-5, further increasing the ratio of HZSM-5 leads to a selectively production of propylbenzene in 62.0% yield. Through careful regulation of the catalytic system and the design of hydrogenation-deoxygenation pathways, excellent yields of 4-propylcyclohexanol (92.2%), propylcyclohexene (93.3%), and propylcyclohexane (93.2%) are directionally achieved. The catalyst maintained a conversion rate of over 99% after five cycles, demonstrating excellent robustness. This study offers a strategic system that expedites the selective upgrading of lignin-derived chemicals, heralding a pathway toward sustainable fuels and chemicals.

Interfacial dynamics and catalytic behavior of single Ni atom site

Abstract Single-atom catalysts (SACs) have garnered significant interest due to their ability to reduce metal particles to the atomic scale, enabling finely tunable local environments and enhanced catalytic properties in terms of reactivity and selectivity. Despite this potential, their application has largely been confined to small-molecule transformations as metal-catalyzed reaction. In this study, we present a diverse single-atom nickel (Ni) catalyst established via a nanoporous carbon (NPC) supported practice. This catalyst represents a breakthrough by achieving the bond formation between carbon and nitrogen and interfacial dynamics in the SAC. The present first principle-based density functional simulations establish the reaction dynamics and catalytic behaviour of such SAC. This dynamic nature comprises an exclusive nitrogen intercalated site showing excellent base effects. This base quickly tunes the interfacial atmosphere, enabling dynamic movement of adatoms into the NPC species, significantly changing the reaction path in Ni SACs due to superior steric effects. The research demonstrates that SACs can extend the capabilities of catalytic systems to include a wider range of complex reactions, offering substantial promise for the development of new, efficient synthetic methods for creating value-added molecular products.

Aryl halide cross-coupling via formate-mediated transfer hydrogenation.

Transfer hydrogenation is widely practised across all segments of chemical industry, yet its application to aryl halide reductive cross-coupling is undeveloped because of competing hydrogenolysis. Here, exploiting the distinct reactivity of PdI species, an efficient catalytic system for the reductive cross-coupling of activated aryl bromides with aryl iodides via formate-mediated hydrogen transfer is described. These processes display orthogonality with respect to Suzuki and Buchwald-Hartwig couplings, as pinacol boronates and anilines are tolerated and, owing to the intervention of chelated intermediates, are effective for challenging 2-pyridyl systems. Experimental and computational studies corroborate a unique catalytic cycle for reductive cross-coupling where the PdI precatalyst, [Pd(I)(PtBu3)]2, is converted to the dianionic species, [Pd2I4][NBu4]2, from which aryl halide oxidative addition is more facile. Rapid, reversible Pd-to-Pd transmetallation delivers mixtures of iodide-bridged homo- and hetero-diarylpalladium dimers. The hetero-diarylpalladium dimers are more stable and have lower barriers to reductive elimination, promoting high levels of cross-selectivity.

Leveraging Solvent Effects for Enhanced Oxidation and Coordination in Selective Piezocatalytic Gold Recovery from End‐of‐Life Electronics

AbstractEfficient gold (Au) recovery from electronic waste (E‐waste) under environmentally sustainable and mild conditions presents a significant challenge in resource recycling. This study introduced a novel piezocatalytic method for Au recovery from E‐waste using a mixed acetonitrile–water (CH3CN‐H2O) solution. The findings emphasize the crucial role of solvent effects in modulating catalytic performance, with a 75% CH3CN solution offering the most efficient recovery. The solvent not only influenced the oxidation and coordination steps crucial for Au extraction but also facilitated electron and mass transfer, accelerating the generation of reactive species that promote Au dissolution. Furthermore, water amplified the effect of the solvent by modifying the chemical potential of surface species, thus optimizing catalytic reactivity. Under ultrasonic vibration, the piezocatalytic system achieved 100% Au recovery from various types of E‐waste, exhibiting excellent adaptability across a broad pH range. Large‐scale experiments at the kilogram level confirmed its practicality, with 100% recovery from printed circuit boards and 98% from central processing unit boards. This study underscores the importance of solvent effects in piezocatalysis and provides new insights into the sustainable recovery of precious metals, thereby paving the way for the design of solvent‐assisted catalytic systems.

Multifunctional Carbon‐Based Metal‐Free Catalysts for Cascade Electrochemical‐Chemical Coupling Catalyses

AbstractCascade electrochemical‐chemical coupling (CECC) involves sequential electrochemical and chemical reactions, using intermediates from electrochemical processes as reactants for subsequent chemical transformations to enhance the efficiency and selectivity for sustainable syntheses of complex chemicals. Despite its economic and environmental benefits, CECC still faces multiple challenges, including a low utilization of intermediate reactants, competitive side reactions, and difficulties in the design and scale‐up of catalysts, leading to low selectivity and yield. To ensure economically viable CECC, it is imperative to rationally design and develop cost‐efficient and high‐performance catalysts, such as carbon‐based metal‐free electrocatalysts (C‐MFECs) and certain carbon‐supported transition metal catalysts, with high activity and selectivity for atomic precision syntheses of desirable products. In this review, an overview of recent advancements in the doping of C‐MFECs is provided for enhancing their catalytic activity and selectivity toward CECC. Three major CECC catalytic systems based on C‐MFECs are discussed; they are hydrogen peroxide coupling, carbon dioxide upgrading, and redox‐mediated systems. Current challenges and future perspectives in this emerging field are also addressed.

Regioselective Alkoxycarbonylation of Styrene Derivatives Catalyzed by Phosphine CN‐Palladacycles

Five new phosphine CN‐Palladacycles 3a‐e were synthesized, characterized, and evaluated in the reaction of alkoxycarbonylation of styrene. The efficiency of catalytic system was influenced by the solvent, auxiliary ligand, source and additives load (acid, salt), CO pressure, and reaction temperature. The CN‐palladacycle 3c with 1,3,5,7‐tetramethyl‐6‐phenyl‐2,4,8‐trioxa‐6‐phosphaadamantane (auxiliary ligand) and tert‐butyl group on the imine fragment was the best precatalyst in the carbonylative process. Structure of 3c was confirmed by single‐crystal X‐ray diffraction. Such a scope of the catalytic system with 3c was evaluated with electron‐donating and electron‐withdrawing styrene derivates in combination with primary, secondary, and tertiary alcohols, furnishing esters with moderate to excellent yield and high‐branched regioselectivity.

Development of a Multi-Bed Catalytic Heat Generator Utilizing a Palladium-Based Hydrogen Combustion System

The growing demand for sustainable energy solutions requires the development of safe and efficient systems for hydrogen utilization. Hydrogen, with its high energy density and clean combustion characteristics, has become a promising alternative for heating applications. However, conventional combustion technologies often suffer from inefficiencies and safety concerns, such as NOx emissions and explosion risks. To address these challenges, this study aimed to design and evaluate a catalytic heat generator utilizing hydrogen–air mixtures under controlled conditions to eliminate the need for pure oxygen and mitigate associated risks. A single-bed catalytic system was developed using palladium-based catalysts supported on ceramic fibers, followed by its heating, activation, and further characterization using the SEM-EDS technique. A multi-bed generator was later constructed to enhance scalability and performance. Thermal imaging and temperature monitoring were employed to optimize activation processes and assess system performance under varying hydrogen flow rates. The experimental results demonstrated efficient heat transfer and operational stability.

Cu-Catalyzed Synthesis of Symmetric Diarylamines from Organoboronic Acids Using NaNO2 as the Amino Source.

A copper-catalyzed novel synthesis of symmetric diarylamines was achieved from aryl boronic acids and NaNO2. This protocol employs aryl boronic acids as the commercially available arylation reagents and sodium nitrite (NaNO2) as the cheap, stable, and solid amino source. Under a simple ligand- and base-free copper catalytic system (CuCl as the sole catalyst), a wide range of symmetric diarylamines could be obtained in moderate to good yields. Notably, the use of Na15NO2 could produce 15N-labeled diarylamines, which would otherwise be difficult to prepare by the known methods.

Recent Advances in Nickel Catalysts for Deoxygenation of Triglycerides and Fatty Acids: A Review

The increasing global demand for fossil fuels and their negative environmental impact have spurred considerable interest in developing renewable fuel sources. Biodiesel, derived from vegetable oils and animal fats, shows great promise as an alternative fuel due to its similar combustion characteristics to fossil fuels. However, the high oxygen content of biodiesel leads to technical challenges in engines. To address this, catalytic deoxygenation has been developed to convert the fatty acids in vegetable oils into second-generation liquid hydrocarbons. This process offers a viable method for the transportation industry to produce biofuels from renewable feedstocks. Palladium (Pd) and platinum (Pt) are commonly used deoxygenation catalysts, known for their excellent performance, but their high cost limits their use in large-scale industrial applications. Nickel (Ni), a non-noble metal, has emerged as a more cost-effective alternative, demonstrating significant catalytic activity for deoxygenation. This review explores the latest advances in the use of Ni catalysts for the deoxygenation of triglycerides and fatty acids. Key focus areas include the deoxygenation process, the role of Ni catalysts, and recent innovations in combining Ni with auxiliary materials to enhance performance. Additionally, the review examines how catalyst loading impacts the deoxygenation efficiency of triglycerides and fatty acids. This study provides crucial insights into the performance of Ni catalysts with different supports, offering a solid foundation for future research into biofuel production using Ni-based catalytic systems.

B(C6F5)3-Regulated Selectivity of Aryl Alkene Hydrosilylation Catalyzed by a [P,C]-Chelate Cobalt(I) Complex.

In this article, two cobalt complexes bearing bidentate ligands, [Si,C]-chelate cobalt(I) complex [(Si,C)Co(PMe3)3] (1) and [P,C]-chelate cobalt(I) complex [(P,C)Co(PMe3)3] (2) were synthesized by activating Csp2-H of the corresponding 2-(diphenylsilylenoaminomethyl) pyridine (L1) PyN(Me)SiL (L = PhC(NtBu)2) or 2-(diphenylphosphinoaminomethyl) pyridine (L2) PyN(Me)PPh2 with CoMe(PMe3)4. The catalytic performance of complexes 1 and 2 for alkene hydrosilylation was studied. Because of the different electronic properties of the phosphine and the silylene pincer ligand, the catalytic effect of phosphine complex 2 is superior to that of silylene complex 1 as indicated by faster conversion and higher selectivity for most of the selected substrates. Both aromatic alkenes and alkyl alkenes are mainly anti-Markovnikov converted to products. In the study of the catalytic mechanism, cobalt(III) hydride A' is proposed as the key intermediate. Unexpectedly, when B(C6F5)3 is added to the system, the selectivity of the catalytic system for aromatic alkenes is reversed to afford mainly Markovnikov products. Through experimental exploration, it is proposed that the addition of B(C6F5)3 induces a coordination vacancy at the Co center, which favors the initial coordination of the olefin and, in turn, changes the catalytic reaction mechanism, resulting in a reversal of regioselectivity.

Photocatalytic Pyridyl-carbamoylation of Alkenes for Accessing β-Pyridyl Amides.

The β-pyridyl amide is a critical scaffold in medical discovery yet lacks efficient synthetic methods. Here, we describe, for the first time, a visible-light-induced, redox-neutral radical cross-coupling reaction involving alkenes, oxamic acids, and cyanopyridines that offers a versatile assembly of β-pyridylamides. This approach features mild reaction conditions, high step efficiency, and substrate breadth, providing a green and efficient strategy for alkene pyridyl-carbamoylation. Achieving this transformation relies on the efficient catalytic system, which adeptly avoids the competing cross-coupling of the nucleophilic carbamoyl radical with the electrophilic pyridyl radical, enabling the three-component radical tandem reaction process with high chemoselectivity.

Atroposelective synthesis of N-N axially chiral pyrrolylamides by combined-acid catalytic Paal-Knorr reaction.

A general and efficient method for the construction of enantiomerically pure N-N axially chiral pyrrolylamides by utilizing the catalytic asymmetric Paal-Knorr reaction has been developed. The key to success is the use of the binary-acid catalytic system involving the dramatic synergistic effect of a Lewis acid and a chiral phosphoric acid for achieving effective stereocontrol.

Green catalytic synthesis of 5‐hydroxymethyl‐2‐furancarboxylic acid in a gram scale over schiff base polymer supported silver‐nanoparticle catalysts

Here, a series of schiff‐base porous organic polymer‐supported silver‐nanoparticle, Ag0 NPs@PPTA‐x were prepared with a two‐step ion coordination/hydrogen reduction. The resulting composite Ag0 NPs@PPTA‐9.08 shows excellent catalytic performance for HMF oxidation to HMFCA, and an impressive HMFCA yield of 99.3% was achieved under optimal condition (NaOH 1.5 eq, 50 mL/min air flow, 20 °C, 6 h). Analysis techniques such as ICP‐OES, XRD, TEM, SEM, N2 adsorption‐desorption, and XPS were employed to characterize the structure and properties of Ag0 NPs@PPTA‐x. The results indicate that the coordination of the nitrogen atom is the key factor for the higher activity and stability of Ag0 NPs@PPTA‐9.08. The results of leaching and reusing tests as well as structural characterization (XRD, SEM, and FT‐IR) shows that the Ag0 NPs@PPTA‐9.08 has good stability and robustness structure. Furthermore, a gram‐scale oxidation of HMF indicates this catalytic system can be readily scaled up to an industrial level. Finally, the results of other aldehydes oxidation over Ag0 NPs@PPTA‐9.08 indicate the good substrate adaptability of the Ag0 NPs@PPTA‐9.08. This work provides a new method for stabilizing nano‐silver catalysts and opens up a simple avenue to selective oxidation of aldehydes that easily to scaled up.

Postsynthetic Modification of Metal-Organic Layers.

ConspectusMetal-organic layers (MOLs), as a subclass of two-dimensional (2D) metal-organic frameworks (MOFs), have gained prominence in materials science by combining the structural versatility of MOFs with the unique physical and chemical properties of 2D materials. MOLs consist of metal oxide clusters connected by organic ligands, forming periodically extended 2D architectures with tunable properties and large surface areas. These characteristics endow MOLs with significant potential for applications in catalysis, sensing, energy storage, and biomedicine.The synthesis of MOLs predominantly follows two key pathways: top-down exfoliation of bulk layered MOFs and bottom-up assembly from molecular building units. The exfoliation method allows for the isolation of ultrathin MOL sheets from bulk precursors, but scalability and structural defects present ongoing challenges. In contrast, the bottom-up assembly offers more precise control over structural design, enabling the formation of MOLs with tailored chemical functionalities and morphologies. By carefully selecting linkers and synthetic conditions, researchers have successfully constructed MOLs with diverse geometric configurations including linear, triangular, and rectangular ligand motifs. Nevertheless, achieving consistent monolayer formation and controlling lateral dimensions remain critical challenges for the widespread application of these materials.A defining advantage of MOLs is their exceptional amenability to postsynthetic modification (PSM). PSM strategies enable fine-tuning of MOL properties and the introduction of novel functionalities without compromising the integrity of the underlying framework. Four principal approaches to PSM have been established: (1) linker modification, where additional coordination sites facilitate selective metalation or functional group incorporation; (2) secondary building unit (SBU) modification, using replaceable sites perpendicular to the MOL plane for targeted functionalization; (3) dual modification, integrating linker and SBU functionalization to achieve complex multifunctional platforms; and (4) multilevel assembly, incorporating MOLs into larger hierarchical architectures such as biomimetic systems and composite materials.These versatile modification strategies have unlocked novel applications of MOLs, including single-site catalysis, photocatalysis, and artificial photosynthetic systems. For instance, MOLs functionalized with transition metal complexes have more accessible reactive sites than conventional MOFs for faster substrate transport. Additionally, MOLs interfaced with biomimetic systems, such as liposomes and proteins, have demonstrated significant promise in photochemical energy conversion and selective oxidation processes.Despite these advancements, several key obstacles persist. Achieving uniform monolayer thickness while preventing multilayer aggregation remains a formidable task, necessitating deeper insights into the thermodynamic and kinetic factors governing MOL growth. Furthermore, the behavior of MOLs during drying, adsorption, and structural modification often deviates from classical models, suggesting the involvement of complex interfacial phenomena that warrant further investigation. Addressing these challenges will be crucial for harnessing the full potential of MOLs in next-generation functional materials.In summary, MOLs represent a versatile and dynamic class of materials that offer opportunities for innovation across diverse scientific disciplines. By advancing synthetic methodologies and deepening our understanding of postsynthetic modification strategies, researchers can continue to expand the functional landscape of MOLs, paving the way for transformative applications in catalysis, energy conversion, and beyond.

Nanoarchitectonics of Palladium Nanoparticles Supported on Carbon‐based Heterogeneous Catalysts for C‐H Activation Reaction

Organic reactions involving the direct functionalization of non‐activated C–H bonds represent a valuable class of transformations, enhancing atom and step economy while streamlining chemical synthesis. However, high stability of C–H bonds often necessitate harsh reaction conditions, significantly limiting their application in synthesizing complex organic molecules. In order to break inert C‐H bond and convert it into useful C‐C, C‐O, C‐X, and C‐N conversion under benign conditions, several active and selective catalytic systems have been designed. Metal (Pd)‐supported carbon‐based heterogeneous catalysts offer a promising approach in this context.Various support such as GO, rGO and CNTs are used as a support material. Pd(II) species activates C‐H bond and involved in oxidation and reduction cycle involving insertion to the substrate and regeneration of catalytic active site. The activation of C‐H bonds in hydrocarbons involves the insertion of a metal into the C‐H bond resulting in formation of organometallic complex which then reacts with another substrate (reaction partner) to yield the final product. Sometime efficiency of Pd metal can be increased by using another metal which helps to reduce HOMO‐LUMO gap and stabilize the catalyst. Therefore, this minireview discuss the most recent advancement of Pd supported on carbon based heterogeneous catalyst for C‐H activation.

Design and application of photocatalysis in solid solution materials.

The research progress of solid solution materials in the field of photocatalysis was introduced. The synthesis methods of solid solution photocatalytic materials are comprehensively expounded, and the modification strategies of solid solution photocatalysts are analyzed and discussed. This paper systematically summarizes the characteristics and development of the main catalytic systems of solid solution materials, and explored the application of first-principles calculations in the photocatalysis of solid solution materials in combination with practical research. Subsequently, the main application progress of photocatalysis of solid solution materials in the fields of environmental remediation and energy conversion was introduced. Finally, the current challenges, development directions and prospects are prospected.

Studies of Catalytic Activity of New Nickel(II) Compounds Containing Pyridine Carboxylic Acids Ligands in Oligomerization Processes of Selected Olefins and Cyclohexyl Isocyanide.

Catalysts based on nickel(II) ions, due to their high reactivity and easiness of ligand modification, are among the most widely used catalytic systems in the world, with applications in a variety of catalytic processes. Here we present research that led to the synthesis of new nickel(II) complex compounds containing nicotinic and isonicotinic acid ligands. Their catalytic properties have been studied in oligomerization processes of olefins and isocyanides and the obtained oligomers were subjected to qualitative and quantitative analysis to determine their physicochemical properties. The catalytic activity values achieved in the oligomerization of olefins, only in a few cases reached above 100 g·mmol-1·h-1·bar-1. However, the newly obtained catalytic systems showed very high (99%) and moderate (36%) efficiency in the oligomerization of cyclohexyl isocyanide. The conducted studies provide knowledge about the influence of modification of the main ligand and reaction conditions on the values of catalytic activity, process yields, as well as physicochemical properties of the obtained oligomers. Furthermore, it was possible to determine which of the processes carried out using the newly synthesized catalytic systems achieve better results and in which process they should be further used and developed.