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Abstract: The generalization use of therapeutic and illicit drugs are introducing new several chemical pollutants in water. They have been detected in water and sewage samples worldwide, hence they are considered as emerging pollutants. The increase of water threats has a negative impact on the life quality and human health. Among the illicit drugs, cocaine and derivatives are increasingly present, making efficient detection and elimination of wastewater highly prioritaire. In that sense, the main core of this work is the assessment of a novel cost‐efficient electrochemical method based on substrate electro‐oxidation (EO) using low‐cost anodes based on common graphite modified with TiO2 nanosized particles incorporated on the surface by assisted microwave deposition. Two different diameters (2 and 5 nm) of nanostructured TiO2@C anodes were tested for cocaine EO reaction using three different electrolytic solutions (NaCl 50 mM, Na2SO4 50 mM or Na2SO4 100 mM). In all cases, the electrochemical oxidation of cocaine appears to be a combination of hypsochromic and hyperchromic processes. Reaching ca. 90 % degradation after 10 minutes for all electrodes, an enhanced efficiency was especially observed for the system with higher cylindrical diameter and NaCl salt medium. The differential pulse (DP) voltammogram, carried out with all assay solutions after 10 minutes of anodic remediation at both electrodes, exhibited an anodic peak consistent with catechol like compounds. [ABSTRACT FROM AUTHOR]

Abstract: Furfural takes an important position in hemicelluloses biorefinery platforms. It can be converted into a wide range of chemicals. One important valorization route is the catalytic hydrogenation. Whereas molecular hydrogen is mostly used in industrial hydrogenation processes, recent studies also showed that alcohols can be used as reductants from which hydrides can be transferred catalytically to furfural. This process is often assisted by the formation of significant amounts of side products, in despite of high yields to the hydrogenolysis product 2‐methylfuran. The present work explores the catalytic behavior in batch and continuous flow of mono‐ and bimetallic nickel catalysts supported on activated carbon for the catalytic transfer hydrogenation of furfural in isopropanol. [ABSTRACT FROM AUTHOR]

TiO2 (anatase phase) has excellent photocatalytic performance and different methods have been reported to overcome its main limitation of high band gap energy. In this work, TiO2-magnetically-separable nanocomposites (MAGSNC) photocatalysts with different TiO2 loading were synthesized using a simple one-pot mechanochemical method. Photocatalysts were characterized by a number of techniques and their photocatalytic activity was tested in the selective oxidation of benzyl alcohol to benzaldehyde. Extension of light absorption into the visible region was achieved upon titania incorporation. Results indicated that the photocatalytic activity increased with TiO2 loading on the catalysts, with moderate conversion (20%) at high benzaldehyde selectivity (84%) achieved for 5% TiO2-MAGSNC. These findings pointed out a potential strategy for the valorization of lignocellulosic-based biomass under visible light irradiation using designer photocatalytic nanomaterials. [ABSTRACT FROM AUTHOR]

The microwave-assisted conversion of levulinic acid (LA) has been studied using low-loaded supported Fe-based catalysts on porous silicates. A very simple, productive, and highly reproducible continuous flow method has been used for the homogeneous deposition of metal oxide nanoparticles on the silicate supports. Formic acid was used as a hydrogen donating agent for the hydrogenation of LA to effectively replace high pressure H2 mostly reported for LA conversion. Moderate LA conversion was achieved in the case of non-noble metal-based iron oxide catalysts, with a significant potential for further improvements to compete with noble metal-based catalysts. [ABSTRACT FROM AUTHOR]

A simple, innovative, and efficient continuous flow methodology for the direct preparation of supported nanoparticles on porous materials by using metal precursor solution flowing through heated packed-bed reactors containing the support material has been developed. The effects of the flow rate of the precursor solution, temperature, and nature of the support material and metal loading have been investigated. Results indicated that optimum conditions comprised short residence times (with typical flow rates of 0.5 mL min−1 and below) under mild heating (100 °C) to achieve optimum materials in terms of nanoparticle size and structure and catalytic activity. The support was found to have a remarkable effect on both loading and distribution and agglomeration of nanoparticles in the system, with a previously reported Fe/Al synergy also observed in the prepared nanomaterials, which led to optimum results. [ABSTRACT FROM AUTHOR]

The hydroconversion of cinnamaldehyde as an α,β-unsaturated compound was studied using a simple and efficient hydrogen-donating protocol catalyzed by mechanochemically synthesized bifunctional Pd/ Al-SBA-15 catalysts. Materials were characterized using TGA-TDA, nitrogen physisorption, TEM and EDX analyses. Catalytic results pointed to the presence of competitive pathways that are able to provide a selectivity switch from the expected fully hydrogenated aromatic ring (e.g. cyclohexane) and hydrogenated products (e.g. hydrocinnamaldehyde, cinnamyl alcohol and 3-phenylpropan-1-ol) to the unexpected ethylbenzene and oxalic acid products from hydrodeformylation and hydrocarboxylation reactions of cinnamaldehyde and formic acid, respectively. [ABSTRACT FROM AUTHOR]

Cu nanoparticles have been supported by two types of aluminosilicate materials with and without Zn in their composition in view of their application in the microwave-assisted conversion of glucose to valuable products via tandem formic acid-promoted dehydration (to 5-hydroxymethylfurfural―HMF) and further selective hydrogenation to 5-methylfurfuryl alcohol (MFA). Results show that interesting selectivities (up to 60% to MFA or HMF) could be achieved after short times of reaction (typically 2–30 min) using Cu-containing nanomaterials. Zn was found to play an interesting role in the selectivity to reduced products, even if present in very small quantities (0.2 wt%). [ABSTRACT FROM AUTHOR]

Microcystin-leucine arginine (MC-LR) is the most abundant and toxic secondary metabolite produced by freshwater cyanobacteria. This toxin has a high potential hazard health due to potential interactions with liver, kidney and the nervous system. The aim of this work was the design of a simple and environmentally friendly electrochemical system based on highly efficient nanostructured electrodes for the removal of MC-LR in tap water. Titania nanoparticles were deposited on carbon (graphite) under a simple and efficient microwave assisted approach for the design of the electrode, further utilized in the electrochemical remediation assays. Parameters including the applied voltage, time of removal and pH (natural tap water or alkaline condition) were investigated in the process, with results pointing to a high removal efficiency for MC-LR (60% in tap water and 90% in alkaline media experiments, under optimized conditions). [ABSTRACT FROM AUTHOR]