This study investigates the catalytic oxidation of phenol using an iron-supported natural illite clay catalyst, focusing on optimizing degradation efficiency and minimizing environmental impact. Phenol, a hazardous industrial pollutant, poses risks to ecosystems, particularly affecting plant germination and fish survival in contaminated waters. To address these concerns, an iron-impregnated natural illite clay catalyst was developed to enhance the stability and reactivity of iron sites, promoting effective phenol degradation in wastewater.

The optimal degradation conditions were achieved at pH 3 and 50°C, facilitating hydroxyl radical formation and accelerating the reaction kinetics. Under these conditions, the catalyst achieved a 99% degradation rate for phenol and an 83% reduction in chemical oxygen demand (COD), indicating significant pollutant mineralization. Minimal iron leaching was observed, ensuring catalyst stability. Additionally, the H₂O₂ concentration was optimized at 0.5 mM, balancing efficient degradation with reduced chemical use.

To understand the degradation mechanism, scavenger tests confirmed hydroxyl radicals (•OH) as the primary reactive species. The identification of intermediate by-products was performed using high-performance liquid chromatography (HPLC), revealing a stepwise oxidation pathway that demonstrated the effective breakdown of phenolic compounds into less harmful substances. The catalyst also showed excellent reusability over five cycles with minimal activity loss, highlighting its potential for sustainable application. This study demonstrates the potential of iron-supported natural clay catalysts as a cost-effective, environmentally friendly solution for treating phenolic pollutants, reducing toxicity and supporting healthier ecosystems in aquatic environments.

In recent years, nanomaterials have grown in significance across a range of fields, such as electronics, biological sensors, catalysis, and energy. Rapid advancements have been made in the use of materials as heterogeneous catalysts, and characteristics like recyclability and low cost are essential for the circular economy and sustainable development. Thus, due to their durability and high surface area, nanocatalysts have become attractive substitutes for traditional materials.
Hydrogen transfer reactions play a crucial role in various chemical processes, including catalysis, organic synthesis, and energy conversion. Unlike conventional direct hydrogenation, catalytic transfer hydrogenation offers numerous advantages such as cost-effectiveness in hydrogen generation, hydrogenation selectivity, and catalyst recyclability.

Herein, we report the synthesis of various mono- and bimetallic Co_x-Ag_y NPs (Co, Ag, Co-Ag, and Co-Ag core shells) anchored in carboxymethyl cellulose and their deposition on mesoporous natural phosphate (m-NP). First, the colloidal NPs were prepared and then followed-up using spectroscopic methods such as UV—vis, IR, and XRD. Afterwards, the resulting colloids were supported on m-NP using a wetness impregnation method to obtain Co_x-Ag_y@NP nanocatalysts². The developed nanocatalysts were characterized using advanced analytical methods, i.e., XRD, XPS, FESEM-EDX, and TEM. Their ability to generate catalysis and transfer hydrogen were studied to assess the level of metal synergy in the prepared nanocatalysts ³.

High-temperature environments pose significant risks to human health and safety. That is why, these days, textile industries pay great attention to produce multifunctional fabrics. However, reports reveal that these fabrics are prepared with silane derivates, along with gold or silver, which makes them expensive with poor self-cleaning properties. Likely, organic--inorganic nanocomposites represent a new class of materials imparted due to their novel properties and low cost. Herein, we reported a commercially affordable SiO₂/TiO₂@Vinylacetate-ethylene (VAE) formulation for functionalizing fabric. The TiO₂-VAE hybrids were prepared by a ball milling-assisted sol--gel technique and imparted onto the bare fabrics via dip-coating. By taking a different amount of the polymer, the structural property and performance of the composite are optimized and characterized. XRD revealed the incorporation of rutile-TiO₂ on the fabric which has a cellulose I structure. In addition, ATR-FTIR confirmed the covalent interactions between the nano-SiO₂/TiO₂ and cellulose of the cloth without any chemical deterioration of thefunctional groups. In addition, SEM revealed that, unlike the bare cloth, it was composed of a plain surface with a woven network of cellulose fibrils with a thickness of 40 to 50µm, and TiO₂/VAE encompassed multi-thin layers where TiO₂ nanoparticles are immobilized on the surface of the functionalized cotton fibers. EDAX confirmed the presence of carbon, oxygen, titanium, and silicon, which are homogeneously distributed over the cloth surface. Interestingly, the hybrid coated fabric demonstrated a superior reflectance, at 91%, to the bare fabric, which recorded the least NIR reflectance at 73%. Furthermore, the imparted fabric displayed an excellent catalytic self-cleaning ability by the complete removal of methylene blue within 3 hours of sunlight illumination. Incorporating photocatalyst TiO₂ nanoparticles not only enhances UV shielding, but also offers a new self-cleaning character by absorbing sunlight. Thus, in fabric surface engineering, such a simple nanoformulation preparation technique paves the way for practical mitigation of global warming.

The utilization of terpenes and resinous compounds derived from forest ecosystems presents a sustainable approach to developing catalytic materials for organic synthesis and environmental remediation. Terpenes, such as limonene and α-pinene, undergo various transformations—including oxidation, epoxidation, and isomerization—using heterogeneous catalysts like zeolites and acid resins. These processes facilitate the production of pharmaceuticals, fragrances, and biofuels, thereby enhancing both sustainability and economic viability. In the realm of environmental remediation, catalytic technologies play a pivotal role in converting pollutants into non-toxic substances. For instance, the epoxidation of terpenes has been explored for generating bio-based polymers, which can be utilized in applications like wastewater treatment and bioplastic production. Additionally, the conversion of terpenes to biofuels addresses environmental concerns by providing renewable energy sources and reducing greenhouse gas emissions, particularly in the aviation sector (Lapuert et al., 2023). Despite these advancements, challenges persist in optimizing the efficiency of catalysts and reducing associated costs. Recent studies have focused on developing both catalytic and non-catalytic processes for terpene epoxidation, employing various oxidizing agents and process intensification techniques. These efforts aim to improve the reaction selectivity, rates, and scalability, contributing to the commercial feasibility of terpene-derived products (Resul et al., 2023). This study delves into the catalytic capabilities of specific terpene compounds, emphasizing their effectiveness in pollutant removal and their roles in green chemical transformations. By examining their physicochemical properties and catalytic processes, the research underscores the potential of these compounds as environmentally benign alternatives to conventional catalysts. The findings highlight the significance of terpenes and resinous substances in advancing sustainable practices across various sectors, including pharmaceutical synthesis, wastewater treatment, and bioplastic production. In conclusion, harnessing terpenes and resinous compounds from forest ecosystems offers a promising pathway toward sustainable catalytic applications. Continuous research and innovation are crucial for optimizing processes and maximizing natural compounds' environmental and economic benefits.

Dry reforming of methane (DRM) is a promising approach for syngas production, utilizing CO₂ as a reactant to mitigate greenhouse gas emissions and enhance sustainability. Despite its potential, DRM faces significant challenges, including the high temperatures required and catalyst deactivation due to coking and sintering. Perovskite-based catalysts, particularly those doped with transition metals and alkaline earth elements, have emerged as effective solutions due to their structural stability, tunable electronic properties, and ability to disperse active metals uniformly. In this study, the catalytic performance of La_ySr_1-yNi_0.5Mg_0.5O₃ perovskites with varying Sr substitution levels (y = 0.2, 0.4, 0.5, 0.6, 0.8) was investigated for DRM. The catalysts were synthesized via solution combustion synthesis (SCS) and characterized by their ability to enhance CO₂ and CH₄ conversions. The results demonstrated that Sr substitution significantly influenced catalyst performance by altering structural properties, oxygen mobility, and basicity. Catalysts with higher Sr content exhibited improved CO₂ adsorption and activation at lower temperatures, while La-rich samples showed enhanced stability and activity at elevated temperatures. Notably, the y = 0.8 sample achieved the highest CO₂ and CH₄ conversions (80% and 70%, respectively) at 750 °C. These findings underline the synergistic roles of Sr and La in optimizing the catalytic behavior for DRM, providing insights into the design of efficient and stable catalysts. By advancing our understanding of perovskite modifications, this work contributes to the development of sustainable technologies for CO₂ utilization and greenhouse gas reduction.

In this study, a porous three-dimensional polymeric network of poly(3-sulfopropyl methacrylate) [p(SPMA)] is prepared and embedded with silver nanoparticles (Ag NPs) to design a nanocomposite catalyst. Analytical techniques including X-Ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), Rheology, and UV–visible spectroscopy are used to investigate the composition and morphology of the prepared nanocomposite catalyst. The fabricated p(SPMA) hydrogel exhibits a hydrophilic character, with a % swelling of 1974 in an aqueous medium. The porosity of the nanocomposite catalyst is corroborated using SEM, while the skeleton of p(SPMA) and the embedding of the AgNPs are affirmed using EDX. The catalytic performance of the synthesized nanocomposite catalyst is analyzed in the chemical reduction of two different dyes, methylene blue (MB) and methyl orange (MO), and two different nitroaromatic compounds, 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA). The apparent rate constant (k_app) of the catalyst is found to be 0.365x10^-2, 1.059x10^-2, 0.159x 10^-2, and 0.581x10^-2 sec^-1 for 4-NA, 4-NP, MO, and MB, respectively. The synthesized nanocomposite catalyst is recycled ten times in succession through the simple, quick, and effortless process of filtration via a plankton cloth filter, and it is found that the catalyst retains 70% of its activity in the tenth cycle.

The Three-Way Catalyst (TWC) plays a vital role in reducing engine exhaust gas emissions. However, steady-state exposure to exhaust gases can lead to catalyst deactivation via noble metal oxidation or active site poisoning. The periodic switching between rich and lean conditions has been shown to counteract deactivation, particularly enhancing methane oxidation.

This study explores the effect of periodic rich/lean switching (λ = 1 ± 0.02 at 0.5 Hz) on pollutant conversion in a realistic car exhaust gas matrix containing NO, CO, H₂, and hydrocarbons (C1-C5) at 100–400 °C. Cordierite-based monoliths were prepared with alumina–ceria–zirconia washcoat layers loaded with Pd, Pt, and Rh. Two catalysts with identical total Pd contents were compared: one homogeneously coated and another zone-coated with Pd on one-third of the catalyst. Gas composition at the outlet was analyzed using infrared spectroscopy and µ-gas chromatography.

The results show that periodic switching enhanced the conversion of NO, CH₄, and C₅H₁₂ compared to steady-state regimes, attributed to the alternating active site poisoning and regeneration during the rich and lean phases. The zone-coated catalyst exhibited superior performance, likely due to its higher local Pd content, smaller particle size promoting effective Pd-support interactions, enhanced oxygen storage capacity (OSC), and exothermic effects during operation.

This work highlights the potential of periodic switching and zone-coating strategies to optimize catalyst performance while conserving scarce platinum group metals, offering insights into next-generation emission control technologies. Insights from this study have broader implications for catalysis, including gas-to-energy conversion applications.

[reference] Elgayyar, T. et al. Promotional Effect of the Periodic Rich and Lean Switching on the Performance of Three-Way Catalysts and Influence of Metal Zone-Coating. Top Catal (2024) doi:10.1007/s11244-024-02019-2

The eco-friendly synthesis of nanomaterials has emerged in modern science to resolve the increasing concerns of environmental pollution and sustainable development. Metal-oxide NPs, including TiO₂, ZnO, and CuO, are widely studied for their potential in facilitating a sustainable environment. Due to their ease of availability, low cost, chemical stability, and nontoxicity, they are considered the best candidates for environmental pollution control and bioremediation. Among these, CuO NPs have gained considerable focus for their antibacterial and catalytic properties. The green synthesis of nanomaterials using various plant parts promotes sustainable chemistry for the sustainability of the environmental and antibacterial applications. Thus, the plant-based biosynthesis of nanoparticles are highly necessary to achieve such environmental and health sustainability. In the present study, we prepared an eco-friendly, cheap, and straightforward sol–gel synthesis method of copper-oxide nanoparticles (CuO NPs) using the aqueous bark extract of Croton macrostachyus. At 200 mg/mL, the uncalcined CuO NPs demonstrated the highest inhibition diameter for Staphylococcus aureus (S. aureus), with 22±1.3 mm, and for Escherichia coli (E. coli), with 11±0.7 mm. Moreover, the calcined CuO NPs presented notable catalytic performance in reducing 4-nitrophenol to 4-aminophenol in 8 minutes with a removal of 98.79%. The kinetics of the process resulted in an apparent rate constant (K_app) of 0.507 min^-1 with a pseudo-first-order reaction. Therefore, this eco-friendly synthesis method not only eliminates the use of harmful reducing substances but also offers a hands-on solution to environmental pollution and disease-resistant bacteria problems.

Introduction

One of the practical applications of the principle of coherently synchronized oxidation could be the transformation of natural compounds for preparative purposes, and possibly on a larger scale. However, in order to move on to more complex nitrogen-containing heterocyclic compounds, similar in chemical structure to natural ones, it is necessary to study the corresponding reactions involving their individual fragments.

Methods

Oxidation reactions of nitrogen-containing heterocyclic compounds in the presence of N₂O were carried out in the gas phase, without the use of catalysts, at atmospheric pressure. Quantitative and qualitative determination of the resulting reaction products was carried out using “Agilent Technologies 7820A” gas chromatography–mass spectroscopy.

Results

The dehydrogenation reaction of piperidine was studied. As a result of our research (T = 200–400°C), optimal conditions for the dehydrogenation of piperidine were identified, under which a yield of 2,3,4,5-tetrahydropyridine (19.4 wt%) was achieved with a selectivity of at least 98%.

The oxidation of pyridine with N₂O was carried out in a wide range of varying process parameters: feed rate of pyridine and N₂O (T = 550-610°C). Under optimal conditions, the following were obtained: 2,2-dipyridyl with a yield of 23.0 wt.%, and 2,3-dipyridyl with a yield of 18.0 wt.%, selectivity not lower than 95 wt.%.

For the first time, 2,2-ethylenedipyridine was obtained by the oxidation of 2-picoline with N₂O. It has been experimentally shown that the yield of 2,2-ethylenedipyridine and 2,2-methylenedipyridine is 30.3 wt.% and 1.5 wt.%, respectively, where the selectivity is not lower than 96 wt.%.

Introduction: The COVID-19 pandemic has resulted in the increased use of non-steroidal anti-inflammatory drugs (NSAIDs), leading to their accumulation in wastewater, posing risks to human health and the balance of the ecosystem. Therefore, between 2019 and 2021, NSAIDs were detected in water sources at concentrations ranging from a few ng/L to hundreds of μg/L. The most commonly found drugs are diclofenac, ibuprofen, naproxen, acetaminophen, and ketoprofen. Though there are several techniques to reduce the emissions of environmentally unacceptable compounds from wastewater, such as Advanced Oxidation Processes (AOPs), adsorption, chemical precipitation, coagulation/flocculation, and flotation, adsorption is emerging as a simple, sustainable, cost-effective, and eco-friendly method for pharmaceutical contaminant removal.

Methods: In this study, two nanocomposites, i.e., CS/CMC/VAN and the further modified CS/CMC/VAN@GO, were synthesized to remove ketoprofen and naproxen from aquatic solutions. Chitosan, a natural cationic polymer, is combined with vanillin via a Schiff base formation and offers effective and low-toxicity adsorption properties. Moreover, modified chitosan exhibits improved adsorption capacity when combined with carboxymethyl cellulose (CMC) and graphene oxide (GO), which are both known for their low toxicity and biocompatibility. In addition, graphene oxide is widely utilized in water treatment due to its high surface area, mechanical strength, and compatibility with various functional groups.

Results: All the materials were characterized via FTIR and SEM techniques. Adsorption experimental results showed that the data fit better to the PSO model and the Langmuir isotherm model, providing adsorption capacities equal to 51.29 mg/g for ketoprofen and 46.30 mg/g for naproxen, with the optimum CS/CMC/VAN@GO at pH 5.

Conclusion: This research contributes valuable knowledge to the field of water and wastewater treatment, providing a viable solution for controlling pharmaceuticals’ environmental pollution.