ChemCatChem最新文献

A one-step method was developed to synthesize highly ordered, primary amine–functionalized two-dimensional (2D) hexagonal mesoporous polymers, designed to enhance the density of catalytically active sites for CO₂ capture and subsequent hydrogenation to methanol. Incorporation of Pt nanoparticles generates an ordered bifunctional (base/metal) mesoporous system, enabling efficient CO₂ adsorption and optimal metal utilization for effective methanol synthesis from the captured CO₂ at the amine–metal interface. Compared with silica-based materials,^[1,2] this novel polymer achieves a fourfold increase in methanol yield while maintaining 100% selectivity under mild reaction conditions.

Electrocatalytic C–N coupling using gaseous pollutants NO and CO offers a promising alternative to conventional industrial urea synthesis. However, designing efficient electrocatalysts remains challenging due to the complexity of multi-step reactions, which yield diverse products. Herein, based on density functional theory (DFT) calculations, we explore Cu and p-block atoms (B, Al, and Ga) anchored on graphitic carbon nitride as novel heteronuclear double-atom catalysts (DACs) for urea synthesis from NO and CO. The reactants are stably adsorbed on the DACs, while strong d–p orbital hybridization facilitates effective activation and efficient C–N coupling. Among the candidates, CuB@g-C₃N₄ and CuGa@g-C₃N₄ exhibit particularly promising performance, with limiting potentials of −0.55 V and −0.36 V, respectively. Furthermore, these catalysts significantly suppress competing reactions, including the hydrogen evolution reaction (HER) and the formation of *NOH, *COH, and *CHO intermediates, ensuring high selectivity. Our work not only highlights highly efficient p-d DACs for electrocatalytic urea production but also provides a theoretical framework in catalyst design.

Conventional catalytic methodologies for the cycloaddition of CO₂ into epoxides predominantly rely on transition metal-based catalysts in conjunction with detrimental halide-containing cocatalysts. Thus, developing metal and halide-free catalysts that function under ambient conditions is highly desirable. The current research endeavours to synthesize a pyrimidine-based bifunctional organocatalyst via a facile one-step Schiff-base condensation reaction. The synthesized organocatalyst efficiently transforms a wide range of epoxides (35 different epoxides, including 6 challenging internal epoxides) into cyclic carbonates with a minimal catalyst loading of just 0.1 mol% under mild conditions (60 °C–100 °C, atmospheric CO₂ pressure) without solvents and cocatalysts. Comprehensive experimental investigations elucidate how the catalyst facilitates the reaction, emphasizing the intricate interplay of hydrogen (H) bonding, spatial arrangement, and catalyst-substrate interactions. The meticulous analysis, using advanced spectroscopic techniques and density functional theory (DFT) calculations, reveals that hydroxyl groups play a pivotal role in epoxide activation through H-bonding interactions, whereas the imine nitrogen facilitates CO₂ activation through the formation of a carbamate intermediate. These two interactions collectively accelerate the overall catalytic process. Furthermore, the catalyst exhibits remarkable recyclability over six consecutive catalytic cycles. Therefore, this study underscores the potential of rationally designed metal-free catalysts in advancing sustainable catalysis through carbon capture and utilization technologies.

The preparation of powdery heterogeneous catalysts often involves the use of solvents, costly precursors, and thermal treatments in multi-step processes. Herein, we demonstrate the preparation of Ru nanoparticles on TiO₂ via spark ablation coupled with powder aerosolization, offering a clean and simple route with minimal waste generation and reduced pre- and post-synthesis processing. The as-prepared Ru/TiO₂ catalyst is readily active in CO₂ methanation reaction, achieving CH₄ formation rate of 0.21 mmolg_Ru⁻¹s⁻¹ and TOF of 0.11 s⁻¹ at 200 °C, outperforming the corresponding formulation prepared by wetness impregnation followed by calcination. The enhanced performance is attributed to a higher fraction of surface metallic Ru, as spark ablation under inert atmosphere typically yields metallic Ru nanoparticles. Additionally, Ru nanoparticles in the spark-made catalyst are well-distributed over both anatase and rutile TiO₂, driven by Brownian motion and van der Waals adhesion. By contrast, Ru/TiO₂-WI exhibits preferential Ru layer around rutile TiO₂ due to pre-existing RuO₂-rutile TiO₂ epitaxial interactions formed during calcination. This work highlights a sustainable approach for designing highly active low-temperature CO₂ methanation catalysts, with potential versatility for broader catalytic applications.

The Front Cover shows self-propelling catalytic micro-/nanobots (μ-Catbots) coated with Fe₃O₄ and Fe nanoparticles, which decompose H₂O₂ to O₂ and HCOOH to H₂, thus enabling real-time fuel cell powering. Magnetic control allows propulsion, bubble demixing, and easy retrieval. Image-based bubble analysis correlates with L–H kinetics, offering a novel approach for reaction rate evaluation and portable oxygen concentrators. More information can be found in the Research Article by D. Bandyopadhyay and co-workers (DOI: 10.1002/cctc.202500767).

Molybdenum carbide (MoC/Mo₂C), due to its unique noble-like metallic electronic structure, high conductivity, and abundant surface-active sites, exhibits promising catalytic performance for the hydrogen evolution reaction (HER). The directional and controllable synthesis of molybdenum carbide with specific phase composition is crucial for enhancing catalytic performance. This study employs a green and clean electrochemical method to achieve one-step controllable synthesis of a dual-phase MoC–Mo₂C in molten salt. The electrolytic mechanism analysis reveals that MoO₃ reacts with molten salt components to form soluble molybdate. Subsequently, CO₃²⁻ and MoO₄²⁻ as the electroactive ions are co-reduced, and then molybdenum carbide is in situ formatted at the cathode. By controlling the electrolysis temperature, the phase composition and morphology of molybdenum carbide are effectively regulated, yielding a feather-like dual-phase MoC–Mo₂C catalyst. In a 1.0 M KOH solution, the dual-phase MoC–Mo₂C catalyst exhibits a superior HER activity. The low overpotential is only 118 mV at a current density of 10 mA cm⁻² for HER. Furthermore, it exhibits excellent stability, with only a 34 mV overpotential increase at 10 mA cm⁻² after 30 h. This study provides a novel strategy for the clean and resource-efficient utilization of CO₂ to synthesize molybdenum carbide catalysts for high performance.

The Cover Feature shows a sustainable, solvent-free route for CO₂ utilization using a trimetallic NiO–CuO–ZnO catalyst, enabling room-temperature conversion of epichlorohydrin to chloropropene carbonate with 80% yield. This energy-efficient, scalable process avoids precious metals, supports green chemistry, and advances circular carbon economy pathways. More information can be found in the Research Article by J. Rajalakshmi, D. Rajagopal, and A. S. Kumar (DOI: 10.1002/cctc.202500934).

The electrochemical upgrading of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) represents a promising route for producing renewable monomers for biodegradable plastics. However, achieving high conversion and selectivity under industrially relevant conditions remains challenging due to sluggish kinetics and catalyst instability. Herein, we report the rational design of a Ru-doped CoFe Prussian blue analogue (Ru-CoFe PBA) catalyst directly grown on copper foam via a one-step hydrothermal process. Comprehensive structural and electronic characterizations reveal that Ru incorporation induces an electron-deficient state in Co and Fe centers, thereby facilitating the formation of hydroxide species and enhancing HMF adsorption. As a result, the Ru-CoFe PBA/CF electrode exhibits outstanding electrocatalytic activity for HMF oxidation, achieving 100% conversion, 98.9% FDCA selectivity, and 97% Faradaic efficiency in 1 M KOH with 100 mM HMF, along with excellent cycling stability. Furthermore, deployment in a multi-stage continuous flow reactor enables high HMF conversion and FDCA selectivity under a broad range of operational parameters, maintaining stable performance over 150 h of continuous operation. This work highlights the synergistic benefits of heteroatom engineering and flow reactor design, offering a scalable platform for efficient biomass electrooxidation to value-added chemicals.

Tetryliumylidene ions, stabilized by N-heterocyclic carbenes (NHCs), have emerged as promising main-group catalysts for the reduction of carbon dioxide (CO₂). Herein, we report the catalytic activity of aryl- and silyl-substituted silyliumylidenes (1 - 4) in the hydrosilylation of CO₂ with diphenylsilane at room temperature, using acetonitrile as solvent. With a low catalyst loading of 5 mol%, full conversion of diphenylsilane was achieved within a moderate reaction time, yielding a mixture of silylformate, bis(silyl)acetal, and silylated methanol. Mechanistic studies, supported by nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations, suggest that the silyliumylidene ions act as precatalysts, forming sila-acylium ion intermediates that subsequently generate the catalytically active siloxy-silylene species. These findings highlight the potential of NHC-stabilized silyliumylidene ions as efficient and selective main-group catalysts for CO₂ hydrosilylation.

This study investigates the influence of the washing step on the physicochemical properties and catalytic performance of Ni–Al layered double hydroxide (LDH)-derived catalysts for CO₂ methanation. Catalysts were synthesized via co-precipitation and subjected to different washing levels, resulting in final conductivities ranging from 21000 µS/cm (0 W) to < 50 µS/cm (10 W). Nitrogen physisorption and X-ray diffraction analyses revealed that lower conductivity values led to increased surface area, reduced crystallite size, and improved structural homogeneity. H₂-TPR and CO₂-TPD profiles demonstrated that efficient washing enhances metal–support interactions and promotes the formation of stronger basic sites, both of which are critical for CO₂ activation. Catalytic tests showed that the 2 W sample washed to an intermediary level exhibited the highest CO₂ conversion at low temperatures (200–300 °C), whereas more thoroughly washed samples (10 W and 5 W) performed better at higher temperatures (>300 °C), likely due to their superior thermal stability and resistance to sintering. Post-reaction XRD and XPS characterization confirmed the structural integrity of the catalysts, with minimal crystallite growth. Furthermore, the 2 W catalyst maintained structural integrity, showed no coke formation, and experienced less than 3% mass loss in TPO after 51 h of reaction, confirming its excellent long-term stability. These findings highlight the importance of controlling washing conditions during synthesis to optimize the redox behavior, basicity, and overall catalytic efficiency of Ni–Al LDH-derived materials for CO₂ methanation.