ChemCatChem最新文献

Coal tar pitch (CTP), a byproduct of coal chemical industries, requires novel strategies to enhance its value. Advancement of high activity and steady non-precious metal oxygen reduction reaction (ORR) electrocatalysts based on low-cost carbon precursors has emerged as a critical research direction. In this study, a strategy is reported for converting inactive MgAl₂O₄ into a novel and high-performance ORR catalyst MgAl₂O₄-HCPs. MgAl₂O₄-HCPs is designed via the pyrolysis of coal tar-based hyper-crosslinked polymers (HCPs) that are composited using the Friedel–Crafts alkylation reaction, with MgO serving as the template. Nitrogen doping serves as a catalyst to induce the abundant generation of oxygen vacancies, which synergistically interact with the porous carbon matrix to jointly regulate and significantly enhance the intrinsic catalytic activity on the spinel surface. MgAl₂O₄-HCPs show exceptional ORR activity with a half-wave potential of 0.882 V (vs. RHE) and is used as cathode material in zinc-air batteries (ZABs), achieving a peak power density of 174.06 mW cm⁻². This study not only provides an innovative plan for the design of cost-effective spinel-type oxide electrocatalysts but also paves the way for the efficient utilization of coal tar as a valuable resource.

Tri-imidazole derivatives, widely recognized for their broad pharmacological and therapeutic activities such as antibacterial, anticancer, antidiabetic, antifibrotic, antifungal, anti-inflammatory, antitubercular, and antiviral effect, used for efficiently synthesized using tetravalent metal acid (TMA) salts, which serve as heterogenous solid acid catalysts with stronger acidic sites, enhanced thermal stability, and improved selectivity in organic transformations. In this study, tri-imidazole and its derivatives were synthesized under solvent-free conditions using titanium phosphate (TiP), titanium-amino trismethylene phosphonic acid (Ti-ATMP), and titanium-hydroxy ethylidene di-phosphonic acid (Ti-HEDP) as heterogenous solid acid catalysts. The catalysts were thoroughly characterized by PXRD, FT-IR, SEM-EDX, XPS, N₂ adsorption–desorption isotherms, NH₃-TPD, and TGA analyses. A comparative investigation was conducted on the synthesis efficiency and recyclability of the catalysts, with progress monitored by TLC. Furthermore, a novel tri-imidazole derivative was successfully synthesized and confirmed by melting point, NMR (¹H, ¹³C and ¹⁹F) spectral analysis.

The present work investigated the binding of atomically dispersed transition metals to the 2D fullerene quasihexagonal phase C₆₀ (qhp-C₆₀) framework and the catalytic performance of the corresponding single/dual-sided single-atom catalysts for CO electroreduction by means of density functional theory calculations. Compared to isolated C₆₀ molecules, the qhp-C₆₀ framework not only effectively inhibits metal aggregation through its unique confining nanocages and stronger metal–substrate interactions, but also enhances the catalytic activity and selectivity by a more efficient electron-buffering effect. Among all the metal centers examined, Mn was identified as the most promising candidate for selective CO-to-methane conversion.

The photocatalytic conversion of CO₂ to valuable fuels is hampered by intrinsic challenges in charge separation and product selectivity. Therefore, the construction of single active sites (SASs) within metal organic frameworks (MOFs) and covalent organic frameworks (COFs) has emerged as an effective approach to address these limitations. These materials leverage well-defined porous structures to create confined reactive microenvironments and incorporate atomically dispersed active sites that maximize metal utilization and enhance product selectivity. This review systematically summarizes recent advances in the rational design of MOF and COF confined SASs, with emphasis on key strategies, including atomic-level engineering of active sites, modulation of the electronic and optical landscape and confinement effects, and reaction microenvironment engineering. These approaches collectively enhance light absorption, charge carrier dynamics, and intermediate stabilization. Special attention is given to the critical roles of pore confinement, local electric fields, and coordination microenvironments in steering reaction pathways and regulating key intermediates. By combining advanced in situ/operando spectroscopy with theoretical simulations, this review elucidates the fundamental structure–activity relationships governing photocatalytic behavior. Finally, this review outlines future research direction aimed at advancing MOF and COF confined SASs toward practical applications in efficient and stable CO₂ photoconversion.

The electrocatalytic nitric oxide reduction reaction (NORR) presents a promising route for sustainable ammonia production. Transition metal (TM) single atoms coordinated with four pyridinic nitrogen atoms in a carbon matrix (denoted as TMN₄–C) have emerged as a vital class of single-atom catalysts (SACs). Recent studies shown that interfacing TMN₄–C with TM surfaces can significantly boost catalytic performance in several reactions. However, whether such interfacial strategies can similarly enhance NORR activity remains unclear. Herein, we present a comprehensive theoretical investigation of the NORR on the MnN₄–C SACs supported on various metal substrates. Constant-potential first-principles calculations reveal that metal supports, particularly Ag(111), markedly improve NORR performance, reducing the limiting potential from –0.69 V (free-standing MnN₄–G) to –0.39 V. Mechanistic analysis identifies the *NO → *NHO step as the potential-determining step, with the metal–support interface modulating the binding strength and activation of NO intermediates. Electronic structure analysis combined with SISSO-based symbolic regression highlights the spin magnetic moment and dz²-band center of the Mn active center, along with the total charge of the entire system, as key factors controlling activity. Bonding analyses further confirm a donation–backdonation interaction between NO and the Mn center as the underlying activation mechanism. This work provides fundamental insights into interfacial electronic modulation strategies for the rational design of high-performance NORR graphene-based single-atom electrocatalysts.

1,5-Pentanediol (1,5-PDO), produced via catalytic hydrogenolysis of furfural, is a valuable intermediate for polyester polyols, solvents, humectants, green coatings, and elastomers. Although noble metal catalysts exhibit high activity for this transformation, their practical application is hampered by high cost and frequently long reaction times. To address these issues, a Co-CeO₂/SiO₂ catalyst was prepared using a membrane-dispersion microreactor, enabling precise control over catalyst morphology. The obtained catalyst possesses uniformly dispersed Co nanoparticles (∼10 nm) and a mesoporous structure (S_BET: 88.9 m²/g). Under mild conditions (170°C, 4 MPa H₂), complete furfural conversion was achieved within 3 h, giving a 1,5-PDO yield of 39.0%—a competitive result compared with many reported systems. Furthermore, the catalyst maintained excellent stability over five consecutive cycles with only minimal activity loss (< 5%). This work highlights the potential of microreactor-assisted synthesis in developing efficient non‑precious metal catalysts and provides a practical strategy for biomass valorization that balances performance, efficiency, and scalability.

The design of artificial enzymes with non-canonical amino acids (ncAAs) capable of catalyzing non-natural reactions represents a promising frontier in biocatalysis. However, the synthetic challenges and high cost associated with ncAAs bearing catalytic residues have limited progress in this area. Here, we report the development of artificial Friedel–Crafts alkylases using a one-pot strategy that seamlessly integrates the biosynthesis of ncAAs with their site-specific incorporation into proteins via genetic code expansion. This innovative approach enables the functionalization of enzymes with novel catalytic properties tailored for stereoselective Friedel–Crafts alkylation. The artificial Friedel–Crafts alkylase exhibited efficient catalytic activity for the enantioselective Friedel–Crafts alkylation of enals and indoles via iminium activation, yielding a range of chiral indole alcohols with up to 98% enantiomeric excess (e.e.) and 99% yield following directed evolution. By demonstrating the feasibility and advantages of this one-pot strategy, we aim to establish a versatile platform for the design of artificial enzymes and to pave the way for broader applications in enzyme engineering and synthetic biology with in situ biosynthesized ncAAs.

Heterojunctions hold great promise for photocatalysis due to their enhanced photo-generated electron-hole separation efficiency. However, the development of heterojunctions with robust interfacial contact and broad visible light response remains a critical challenge. Herein, hydrangea-like Bi₄O₅I₂/Na_0.5Bi_0.5TiO₃ heterojunctions with an intimate interface were rationally constructed via a facile coprecipitation method. The as-prepared heterojunctions exhibited exceptional visible light-driven photocatalytic performance in degrading various refractory organic pollutants, including bisphenol A (BPA), tetracycline, and Rhodamine B, outperforming the parent compounds Bi₄O₅I₂ and Na_0.5Bi_0.5TiO₃ alone. Notably, the optimized heterojunction catalyst achieved complete (100%) photocatalytic removal of BPA under visible light irradiation. The enhanced activity originates from the synergy of heterojunction formation and uniform hydrangea-like morphology, which promotes photo-generated electron-hole separation/transfer and inhibits their recombination. Mechanistically, the heterojunction follows a Type-II charge transfer pathway, where photo-generated electrons preferentially migrate and accumulate on the conduction band of Na_0.5Bi_0.5TiO₃, while photo-generated holes transfer to and enrich on the valence band of Bi₄O₅I₂. These accumulated electrons efficiently reduce adsorbed O₂ molecules to generate O₂·⁻, which serves as the primary active species driving BPA degradation. This study provides a useful guideline for the design and application of bismuth-based heterojunctions in environmental remediation.