Highly efficient and reusable CNT supported iron(II) catalyst for microwave assisted alcohol oxidation

The highly efficient eco-friendly synthesis of ketones (yields over 99%) from secondary alcohols is achieved by combination of [FeCl2{eta(3)-HC(pz)(3)}] (pz = pyrazol-1-yl) supported on functionalized multi-walled carbon nanotubes and microwave irradiation, in a solvent-free medium. The carbon homoscorpionate iron(II) complex is the first one of this class to be used as catalyst for the oxidation of alcohols

Commercial Gold Complexes Supported on Functionalised Carbon Materials as Efficient Catalysts for the Direct Oxidation of Ethane to Acetic Acid

UIDB/00100/2020 UIDP/00100/2020 LA/P/0056/2020 IST-ID/119/2018 SFRH/BD/146426/2019 CEEC-INST/00102/2018 UIDB/50006/2020 UIDP/50006/2020 Base-UIDB/50020/2020 Programmatic-UIDP/50020/2020The single-pot efficient oxidation of ethane to acetic acid catalysed by Au(I) or Au(III) compounds, chlorotriphenylphosphinegold(I) (1), chlorotrimethylphosphinegold(I) (2), 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidenegold(I) chloride (3), dichloro(2-pyridinecarboxylato)gold(III) (4), homogenous and supported on different carbon materials: activated carbon (AC), multi-walled carbon nanotubes (CNT) and carbon xerogel (CX), oxidised with nitric acid followed by treatment with NaOH (-ox-Na), is reported. The reactions were performed in water/acetonitrile. The materials were selective for the production of acetic acid, with no trace of by-products being detected. The best homogenous catalysts were complexes 2 and 3 which showed the highest ethane conversion and an acetic acid yield of ca. 21%, followed by 4 and 1. The heterogenised materials showed much better activity than the homogenous counterparts, with acetic acid yields up to 41.4% for 4@CNT-ox-Na, and remarkable selectivity (with acetic acid being the only product detected). The heterogenised catalysts with the best results were reused up to five cycles, with no significant loss of activity, and maintaining high selectivity for acetic acid. 4@CNT-ox-Na showed not only the best catalytic activity but also the best stability during the recycling runs.publishersversionpublishe

Kinetic regularities, catalyst deactivation and reactivation

Funding text 1 The research is funded from Ministry of Education and Science of the Russian Federation Program No. 075–03–2021–287/6 (Russia). Funding text 2 XPS measurements were carried out at the Central laboratories of Tomsk Polytechnic University (Analytical Center). HRTEM was carried out at the Innovation centre for Nanomaterials and Nanotechnologies of Tomsk Polytechnic University. The ICP-OES analysis was carried out using the core facilities of “Physics and Chemical methods of analysis” of Tomsk Polytechnic University. Fundação para a Ciência e a Tecnologia for Scientific Employment Stimulus Institutional Call (CEECINST/00102/2018), UIDB/50006/2020 and UIDP/50006/2020 (LAQV), UIDB/00100/2020 and UIDP/00100/2020 (Centro de Química Estrutural).Betulin, being a pentacyclic triterpene alcohol and an extractive from birch bark, along with its oxo-derivatives, has a broad range of physiological properties of interest for synthesis of pharmaceuticals. Instead of oxidizing betulin with strong and toxic oxidizing agents the present study shows a possibility of using liquid-phase oxidation of betulin with air over supported Ag NPs catalysts as an alternative method for synthesis of its oxo-derivatives. Based on catalytic studies, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflectance spectroscopy, the evolution of the surface of nanosilver catalysts during the catalysis was demonstrated, as well as under the impact of reactant gas composition. The kinetic regularities and causes of deactivation of supported Ag NPs catalysts were revealed. An approach to the regeneration of silver catalysts was proposed. Kinetic analysis with numerical data fitting was performed resulting in an adequate description of the concentration dependencies.publishersversionpublishe

Methionine-functionalized graphene oxide/sodium alginate bio-polymer nanocomposite hydrogel beads: Synthesis, isotherm and kinetic studies for an adsorptive removal of fluoroquinolone antibiotics

This work was supported by Pt. Ravishankar Research Fellowship Scheme, Raipur, Chhattisgarh, India (grant number V.R. No. 3114/4/Fin./Sch.//2018). This work was also supported by national funds through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., under the Scientific Employment Stimulus-Institutional Call (CEECINST/00102/2018) and by the Associate Laboratory for Green Chemistry-LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020).In spite of the growing demand for new antibiotics, in the recent years, the occurrence of fluoroquinolone antibiotics (as a curative agent for urinary tract disorders and respiratory problems) in wastewater have drawn immense attention. Traces of antibiotic left-overs are present in the water system, causing noxious impact on human health and ecological environments, being a global concern. Our present work aims at tackling the major challenge of toxicity caused by antibiotics. This study deals with the efficient adsorption of two commonly used fluoroquinolone (FQ) antibiotics, i.e., Ofloxacin (OFX) and Moxifloxacin (MOX) on spherical hydrogel beads generated from methionine‒functionalized graphene oxide/ sodium alginate polymer (abbreviated Met-GO/SA) from aqueous solutions. The composition, morphology and crystal phase of prepared adsorbents were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and thermogravimetric analysis/differential thermogravimetry (TGA/DTG). Batch adsorption tests are followed to optimize the conditions required for adsorption process. Both functionalized and non-functionalized adsorbents were compared to understand the influence of several experimental parameters, such as, the solution pH, contact time, adsorbent dosage, temperature and initial concentration of OFX and MOX on adsorption. The obtained results indicated that the functionalized adsorbent (Met-GO/SA) showed a better adsorption efficiency when compared to non-functionalized (GO/SA) adsorbent. Further, the Langmuir isotherm was validated as the best fitting model to describe adsorption equilibrium and pseudo second-order-kinetic model fitted well for both types of adsorbate. The maximum adsorption capacities of Met-GO/SA were 4.11 mg/g for MOX and 3.43 mg/g for OFX. Thermodynamic parameters, i.e., ∆G°, ∆H° and ∆S° were also calculated. It was shown that the overall adsorption process was thermodynamically favorable, spontaneous and exothermic in nature. The adsorbents were successfully regenerated up to four cycles with 0.005 M NaCl solutions. Overall, our work showed that the novel Met-GO/SA nanocomposite could better contribute to the removal of MOX and OFX from the liquid media. The gel beads prepared have adequate features, such as simple handling, eco-friendliness and easy recovery. Hence, polymer gel beads are promising candidates as adsorbents for large-scale water remediation.publishersversionpublishe

Homogeneous and heterogenised new gold C-scorpionate complexes as catalysts for cyclohexane oxidation

Gold(III) complexes of type [AuCl2{eta(2)-RC(R'pz)(3)}]Cl [R = R' = H (1), R = CH2OH, R' = H (2) and R = H, R' = 3,5-Me-2(3), pz = pyrazol-1-yl] were supported on carbon materials (activated carbon, carbon xerogel and carbon nanotubes) and used for the oxidation of cyclohexane to cyclohexanol and cyclohexanone, with aqueous H2O2, under mild conditions

Users opinion about synthetic, bio- and nano-biopesticides

As authors, we would like to convey our sincere thanks to Department of Chemistry, Govt. V.Y.T. PG. Autonomous College, Durg, for their valuable technical support given in this project. We would like to express our earnest thanks Dr. Poonrathi (Chief Medical Officer in charge - Kodai Govt. Hospital), Dr. Tamilselvan (Junior doctor- Krishnagiri Govt. Medical Health Unit), Ms. N.V. Ratana (Department of Agriculture – Telangana), Dr. Thirupurasundari (Dietician – USA), Ms. Tan (Organic Activist – KL), and Ms. Krithika Lakshmi (HR – Advisor, KL) for their valuable comments, timely advice, and suggestions. We also would like to thank all participants for devoting their precious time by helping us in this survey. We would like to share our humble gratitude to Dr. R. Senthil Kumar, Assistant Professor, Department of Statistics, Madras Christian College (Autonomous), Chennai, for his timely help and advice for statistical evaluation. SACC is grateful to Fundaç ão para a Ciência e a Tecnologia (FCT), Portugal for Scientific Employment Stimulus-Institutional Call (CEEC-INST/00102/2018) and to the Associate Laboratory for Green Chemistry - LAQV financed by national funds from FCT/MCTES (UIDP/5006/2020). The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board (or Ethics Committee) of Govt. V. Y. T. PG Autonomous College, Durg (protocol code IEC/GVYTPGACI 19 /DURG. Date- 30/10/2021) for studies involving humans. Informed consent was obtained from all subjects involved in the study. Publisher Copyright: © 2023 The AuthorsWith a growing global population, the demand for food, clothing and shelter became crucial for sustaining life. Moreover, the COVID-19 pandemic/endemic, along with the threat of other endemics, posed significant challenges in ensuring the delivery of nutritionally rich food. To address this, the World Health Organization (WHO) recommended the ban of some highly toxic chemical pesticides. Excessive consumption and exposure to pesticides possibly contributed to a decline in the human immunity levels making our fight against the pandemics more difficult and challenging. During the lockdown COVID-19 crisis, we conducted a survey to gather insights from farm landers (FLs), garden lovers (GLs), domestic front users (DFUs) predominantly from India, but also from other regions worldwide. The survey aimed at better understanding the usage of pesticides, both chemicals (CPs), bio-pesticides (BPs) or both, and their global utilization. A statistical survey with seven rudimentary sections was designed to receive the inputs (elementary inputs, awareness and perception, pesticide utility, health, ecology, and alternatives for safer trials) with fairness and care. The data was statistically analyzed within each group of population, revealing significant variations within the groups. Our study indicated that FLs (44.7 %) predominantly used BPs, GLs (18.8 %) relied on CPs, while DFUs (100.0 %) used a combination of both without any specific intention. Correlation analysis, given by R (correlation coefficient) and p (probability of obtaining an equal or more extreme effect than the found considering the null hypothesis as true) values revealed the existence of a positive and significant relationship between the selected variables, such as level of education (LOE) and gender, with the adoption of new alternatives (2loglikelihood = 64.743, with χ2 = 128.4, degrees of freedom (df) = 24, p<*0.05, **0.01, and *** 0.001) through multinomial regression analysis, indicating the fitness of the model. Likewise, our study primarily focused on exploring the insights for the development of nano-biopesticides, as improved alternatives to the existing solutions.publishersversionpublishe

Влияние модификации поверхности носителя на активность палладиевых катализаторов жидкофазного гидрирования фурфурола

Noble causes: Cellulose is effectively converted into methanol, propylene, and ethylene glycol over Cu-based catalysts. Overall yields of above 93 %, together with 63 % yield of C1–C3 compounds, can be reached over simple noble-metal-free systems, opening new opportunities for the sustainable and cost-efficient valorization of cellulose