Catalysis Communications最新文献

Lignin is an aromatic polymer with prospects for producing high value-added chemicals. In this study, hydrogenolysis of alkaline lignin was carried out at 240 °C for 8 h in a hydrothermal kettle using Ni/xCeO₂-yAl₂O₃ as catalyst and formic acid as hydrogen source. Compared with Ni catalysts supported by single oxides, the results showed that Ni/xCeO₂-yAl₂O₃ composite-supported catalysts exhibited better catalytic depolymerization performance with higher bio-oil yields. Among them, Ni/1CeO₂–3Al₂O₃ exhibited the most outstanding catalytic activity, with a bio-oil yield of 52.77 wt% and a phenolic compound yield of 7.21 wt%.

Water pollution caused by antibiotics poses a serious threat to human health and ecosystems. Rapid and efficient removal of antibiotic pollution in water by photocatalysts is one of the effective means to protect the environment and public health. Herein, a wide-spectral responsive upconversion NaGdF₄:Yb,Tm@Mn-MOFs core-shell nanostructures were built by coating hexagonal NaGdF₄:Yb,Tm cores with amino-functionalized manganese carboxylate MOFs (Mn-MOFs) shells, which exhibited good water dispersibility. Mn-MOFs catalysts is mainly concentrated in the ultraviolet region, while NaGdF₄:Yb,Tm nanoparticles can transform infrared light into visible light or even higher energy ultraviolet light, which is harvested by the Mn-MOFs. The optimized nanostructures were tested under simulated solar light (After 120 min irradiation) in the degradation of tetracycline, oxytetracycline hydrochloride and tetracycline hydrochloride, while their degradation rates reached 70%, 72% and 75%, respectively. The better photocatalytic mechanism for antibiotics than its individual components was elucidated, which provides a potential strategy to broaden the full spectrum absorption of the wide bandgap semiconductors and apply for the field of environmental remediation.

This article reviews recent studies about various generations of the carbon materials for their applications in energy and environmental remediation. The synthesis routes of the carbon materials including the condition parameters, interaction of precursors, dopants and carbon materials, as well as their physical/chemical properties are explicated first. Then, the application and mechanism of metal-free/metal-doped/non-metal-doped carbon materials are discussed in detail. Lastly, this review is ended with a summary and invigorating perspectives on the challenges and future directions at the forefront of the catalysis platform to take a step further for real application.

The grafting of Ga(iBu)₃ on a series of meso-H-ZSM5, prepared by desilication-dealumination (Si/Al = 25, 50, 100, 200, ∞), has been studied. Materials were characterized by IR, solid-state NMR, BET, ICP and EXAFS. Ga(iBu)₃ reacts selectively with silanol groups, yielding a monopodal surface species in the mesopores. Importantly, the Brønsted acidic sites remain intact in the micropores, as revealed by IR and ¹H MAS-NMR. These materials can be regarded as bifunctional catalysts, containing isolated Ga sites and Brønsted sites in proximity, suitable for propane aromatization. Catalytic investigations show high activity and selectivity toward aromatics, particularly for low Si/Al ratios.

This study's objective is to examine the potential of the chitosan-supported Ag and Ag₂O nanoparticles on the reduction of CO₂. The transition state of the reduction reaction was systematically calculated using the nudged elastic band and the semi-empirical tight-binding calculations. It is found that the large charge polarization on the Ag and Ag₂O nanoclusters can modulate chitosan's surface reactivity. The formation of the metal hydrates is the rate-determining step for reducing CO₂. The calculated activation energy of the order of 1.5 eV demonstrates that Ag and Ag₂O /chitosan could be used as catalysts for converting to CO₂ formic acid_.

Unactivated bean sprout (Faba pullulat) biochar (BSB) supported cadmium sulfide composites (CdS/BSB) were prepared by hydrothermal combined with freeze-drying without adding any activation agent. The structure and morphology have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in detail, respectively. CdS/BSB(5:4) with a mass ratio of CdS to BSB of 5:4 had the highest photocatalytic hydrogen production rate of 17.7 mmol.g⁻¹.h⁻¹, which is about 3.93 and 3.2 times that of synthesized CdS without biochar and the commercial activated carbon supported CdS, respectively. These results suggested that biochar derived from bean sprout could be a low-cost, renewable, environmentally friendly and metal-free cocatalyst for hydrogen generation.

This study proposes a new approach for the efficient photodegradation of polycyclic aromatic hydrocarbons (PAH) and derivatives. PAH removal was achieved in just a few minutes using a microwave photochemical reactor capable of producing a high concentration of ^•OH (2.3 mmol L⁻¹ h⁻¹). Fluorescence excitation-emission matrix (EEM) spectroscopy coupled to parallel factor analysis (PARAFAC) was used for quantifying two PAH and one alkylated PAH at low concentrations (μg L⁻¹). These results highlight the high potential of the photochemical degradation system coupled to EEM-PARAFAC as an alternative fast, inexpensive, and efficient approach for environmental remediation studies of PAH.

The advancement of extremely effective and long-lasting sustainable electrocatalysts developed from abundant earth elements is an emergence aspect in green energy generation. The greenly synthesised NCF-LDH has been shown that promising candidate for the OER process. Mechnochemical processes are often quick, inexpensive, and easily scalable to produce industrial quantities. In comparison with IrO₂ (370 mV), the optimum NCF-LDH-X on GC electrode showed the modest required overpotential (240 mV) at 10 mA cm⁻². Solar-assisted water oxidation at 1.57 V shows more expert efficacy of NCF-LDH-2 for solar to hydrogen generation. As an outcome, the greenly synthesised NCF-LDH outperformed the high-priced electrocatalysts. Consequently, low-cost industrial-scale H₂ generation using commercial solar cells might be possible.

Lime (Citrus aurantifolia) is one of the most extensively exported agricultural products from Indonesia. Citric acid and ascorbic acid content from limes (Citrus aurantifolia) is such one of the carbon-rich fruits that is a suitable source for Carbon Quantum Dots (CQDs) synthesis. CQD synthesized by relying on natural carbon precursors from lime (Citrus aurantifolia) is a more environmentally friendly approach in the present research, CQDs in this research will be used as an addition to ZnO by hydrothermal method in order to enhance photocatalytic activity. Corresponding to the results, the presence of CQDs improves both the optical and structural properties of ZnO, which led to enhance photocatalytic activity with a degradation percentage of 98% shortly after 75 min of visible light irradiation and to each of the repeatability test cycle results showing the consistent results and with the rate constant (k) fluctuating and the specified compound's degradation percentage remains relatively constant with minor changes.

A novel Deep Eutectic Solvent (ChCl/THFTCA-DES) was prepared by a mixture (2:1) of choline chloride [(CH₃)₃N⁺CH₂CH₂OH]Clˉ = (ChCl) and tetrahydrofuran-2,3,4,5-tetracarboxylic acid (THFTCA) as a cheap, simple, and non-toxic method, characterized by FT-IR, densito-meter, eutectic point, and ¹H NMR techniques and used as a capable and new catalyst for the synthesis of ten Henna-based benzopyranophenazine‑carbonitriles.