Catalysis Science & Technology最新文献

A series of NiZn catalysts (Ni_xZn_y@C) were prepared by changing the Zn content to control the phase composition. The ethyl levulinate (EL) conversion improved 2.4-fold, from 38.5% for Ni@C to a remarkable 93.9% for Ni₃Zn₁@C. The excellent performance is attributed to the regulation of the Zn content, which forms a single Ni₃ZnC_0.7 phase. The experimental results and density functional theory (DFT) indicate that the Ni₃ZnC_0.7 phase significantly improves H₂ and EL adsorption. In addition, the carbon-coated structure of the catalyst helps to improve the cycle stability.

Cobalt and iron elements were incorporated into the defect-rich surface layer of NiO_x, enabling dynamic reconstruction during the oxygen evolution reaction, which achieved a low overpotential of 280 mV at 10 mA cm⁻² and maintained stable operation for 900 hours—18 times longer than that of the defect-rich NiO_x.

To address the challenge of antibiotic-contaminated water remediation, we designed a defect-engineered CoSe₂@MoS₂ photocatalyst by integrating selenium-deficient CoSe₂ dodecahedra (derived from ZIF-67) with vertically aligned MoS₂ nanosheets. The catalyst achieved 90.4% visible-light-driven tetracycline (TC) degradation within 60 minutes, demonstrating a 3.1-fold performance enhancement over pristine MoS₂ due to the synergistic effects of atomic-scale defect engineering and heterostructure design. Density functional theory (DFT) calculations revealed a dual enhancement mechanism: selenium vacancies introduced localized mid-gap states, increasing the photogenerated electron density by 2.8-fold, while the CoSe₂/MoS₂ heterojunction formed a type II band alignment, facilitating interfacial electron transfer via a built-in electric field. In situ spectroscopic analysis confirmed the vacancy-mediated enhancement of reactive oxygen species (·OH/·O₂⁻) generation, showing a 2.8-fold increase in yield. DFT-guided quantitative analysis further demonstrated that the improved activity resulted from the synergistic interaction between heterojunction formation and vacancy modulation. The catalyst exhibited excellent environmental stability, maintaining >88% efficiency over 10 cycles with minimal metal leaching (<0.2 ppm). These findings advance the development of photocatalysts for visible-light-driven wastewater treatment, addressing the critical trade-offs between catalytic efficiency, operational stability, and ecological compatibility.

Effluents from the pharmaceutical industry pose significant environmental threats due to their complex and recalcitrant nature, including low biodegradability, high organic load, and the presence of emerging contaminants such as pharmaceutical residues. In this study, polysulfone (PSF) ultrafiltration membranes were modified with zinc oxide–graphene oxide (ZnO–GO) nanocomposites at varying loadings (0.6 and 1.2 wt%) via the phase inversion method to enhance their separation efficiency and photocatalytic performance. Physicochemical characterization was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), Fourier transform infrared spectroscopy (FTIR), contact angle analysis, and mechanical strength tests. The photocatalytic performance of the membranes was evaluated through the degradation of diclofenac (DCF), a model pharmaceutical contaminant, under UV irradiation (24 W) at an operating pressure of 3 bar. The membrane incorporating 0.6 wt% ZnO–GO exhibited the best overall performance, achieving a high-water flux of 19.12 L m⁻² h⁻¹ bar⁻¹ and an 80% DCF removal efficiency. Furthermore, antifouling evaluation using bovine serum albumin (BSA) demonstrated a rejection rate of 91% and a flux recovery ratio (FRR) exceeding 86%, indicating strong resistance to fouling. These results demonstrate the potential of PSF/ZnO–GO nanocomposite membranes as high-performance, multifunctional systems for the advanced treatment of pharmaceutical wastewater, combining efficient filtration with photocatalytic degradation capabilities.

We report the design and synthesis of task-specific room-temperature ionic liquids (RTILs) from picolinic acid, a naturally occurring, non-toxic bulk chemical, via a conventional cation-exchange acid–base reaction. These picolinate-based ionic liquids serve as metal- and halide-free bifunctional organocatalysts for the cycloaddition of CO₂ to epoxides, enabling the efficient synthesis of industrially relevant cyclic carbonates under solvent-free conditions. The presence of a carboxylate group adjacent to the pyridine nitrogen significantly enhances the nucleophilicity of pyridine N, facilitating epoxide activation and CO₂ insertion under mild conditions. Low catalyst loading (∼0.6%) with excellent yields (>99%) and selectivity (>99%) further enhances the utility of the system. Control experiments and DFT calculations revealed that the enhanced activity resulted from pyridine-mediated substrate activation, while the carboxylate group modulated the nucleophilicity of the catalyst. Catalyst recyclability along with a broad substrate compatibility was explored, including the challenging spirocyclic systems. Green chemistry metrics from Chem21 toolkit and EcoScale analysis emphasize the sustainability of this approach, highlighting the facile synthesis, operational simplicity, and minimal waste generation. This work advances the development of halide-free, reusable IL-based organocatalysts for CO₂ valorization.

The catalytic hydrogenation of carbon monoxide (CO) to methanol using manganese pincer complexes remains a significant challenge, requiring a deeper mechanistic understanding to guide the development of more efficient systems. In this study, we performed a comprehensive density functional theory (DFT) investigation to elucidate the reaction mechanism of CO hydrogenation catalyzed by a manganese complex bearing a pincer ligand. Our theoretical results reveal that the catalytic cycle proceeds through four key stages: (i) formation of N-formylpyrrole; (ii) formation of 1-pyrrolylmethanol; (iii) regeneration of the pyrrole (Pyr) and formation of formaldehyde; and (iv) the formation of the final product methanol. Among these, the cleavage of the C–N bond during the Pyr regeneration step was identified as the rate-determining step (RDS), with a free energy barrier (ΔΔG^‡) of 22.1 kcal mol⁻¹. In addition, our study highlights the essential role of K₃PO₄ in the reaction. Rather than acting as a simple base, K₃PO₄ functions also as a promoter that facilitates CO activation and promotes C–N bond formation in the early stages of the catalytic cycle. Based on these mechanistic insights, we further designed a modified catalyst structure with the potential to enhance the efficiency of Mn-catalyzed CO hydrogenation. This work provides valuable theoretical guidance for the rational design of next-generation catalysts aimed at sustainable methanol production from CO.

A novel Cu–B₂O₃/porous boron nitride (PBN) composite was developed as a highly efficient and reusable heterogeneous catalyst for the solvent-controlled conversion of arylboronic acids. In water, the catalyst promotes ipso-hydroxylation to phenols, while in methanol, it facilitates aerobic homocoupling to biphenyls, using air as a green oxidant. The synergistic interaction between Cu nanoparticles and B₂O₃ sites enhances both catalytic activity and stability. This work offers a sustainable and selective approach for synthesizing phenolic and biphenyl compounds under mild conditions.

The direct synthesis of dimethyl carbonate (DMC) from CO₂ represents a promising carbon-negative strategy for simultaneously producing high-value chemicals and mitigating greenhouse gas emissions. However, this approach faces fundamental challenges due to thermodynamic equilibrium limitations and the chemical inertness of CO₂. In this work, we developed a novel CeO₂–HMOR bicomponent catalyst that synergistically integrates nanorod-structured CeO₂ with HMOR zeolite. This catalytic system enables the efficient coproduction of DMC and methyl formate (MF) through CO₂–methanol coupling assisted by 1,1,1-trimethoxymethane (TMM) as a dehydration agent. Remarkably, the optimized CeO₂–HMOR catalyst achieves exceptional catalytic performance, with DMC and MF yields reaching 44.3% and 74.6%, respectively, and a DMC formation rate of 821.2 mmol g_CeO2⁻¹. Through combined in situ IR analysis and density functional theory (DFT) calculations, we reveal that the large pore size, strong acid sites, and enhanced hydrophilicity of HMOR synergistically promote TMM hydrolysis, accelerate the reaction of methyl carbonate with bridged methoxy species to produce DMC and H₂O, and suppress the formation of by-product dimethyl ether. This work not only demonstrates a breakthrough in CO₂-to-DMC conversion efficiency but also establishes a generalizable catalyst design principle for overcoming thermodynamic limitations in CO₂ utilization via acid–base cooperative catalysis.

Oxidation of primary alcohols to carboxylic acids is a fundamental reaction in organic chemistry, traditionally dependent on toxic oxidants and often limited by poor selectivity. In this study, we demonstrate the multifunctional capability of some alcohol dehydrogenases (ADHs) to catalyze both alcohol and aldehyde oxidation while regenerating their NAD⁺ cofactor through concomitant reduction of acetone. Screening of a panel of ADHs revealed that the enzymes from Paracoccus pantotrophus (Pp-ADH) and Aromatoleum aromaticum (Aa-ADH) have strong overoxidation activity to carboxylic acids. The biocatalytic method was assessed for the efficient oxidation of a panel of 27 structurally diverse primary alcohols into carboxylic acids using a single enzyme, with minimal workup and without the need for further purification. The biotransformation was also scaled up using cell-free extracts, while maintaining high yields. In silico studies provided insights into substrate tolerance, highlighting the structural features that govern enzyme activity. This biocatalytic method provides a scalable, selective, and environmentally friendly alternative to conventional oxidation strategies for primary alcohols to carboxylic acids.

Chlorine radicals (Cl·) exhibit a remarkable ability to initiate a variety of highly efficient reactions. However, the sluggish and inefficient generation of Cl· radicals remains a challenge. More critically, the presence of excessive Cl· with a short lifetime leads to the formation of an undesired byproduct. The rational control of Cl· generation is crucial for the efficient dichlorination reaction. Herein, we use a photoelectrochemical (PEC) method to generate a significant amount of Cl· for chlorination reactions. The selectivity for the vicinal dichlorinated product reached 70%. Then, we manipulate the generation of Cl· by introducing a trace amount of Mn²⁺ (10 μmol) and achieve a high yield of 91% and a faradaic efficiency of 90% for the dichlorinated product. The Mn²⁺ participates in the reaction process and forms the [Mn³⁺–Cl] complex, which facilitates the addition reaction of the chlorinated intermediate and then enhances the selectivity of the final products. This study paves a new pathway for solar-driven alkene dichlorination and provides new insights into photoelectrocatalytic synthesis.