Painted Goby Larvae under high-CO2 fail to recognize reef sounds

Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus) were exposed to control pCO2 (532 μatm, pH 8.06) and high pCO2 (1503 μatm, pH 7.66) conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.Fundação para a Ciência e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio

Application of Ionic Liquids for Sustainable Catalysis

International audienceSustainability in chemistry is strongly connected to the green chemistry and circular economy concepts, having as objectives the reduction of the usage of hazardous substances and of energy consumption, the minimization of the resource input and wastes and the minimization of the emissions and energy leakage. On this basis, a sustainable chemistry must ensure the longevity of humans, animals and ecosystems by allowing for serene development, and also maintaining economic competitiveness to create profit and business. In this multidisciplinary approach, the role of the solvent is very important. Many organic solvents are harmful, toxic and environmentally damaging, and their use poses risks to both human health and the environment. Therefore, to avoid any negative effects, in addition to eliminating solvents exhibiting such negative properties, a proper solvent should: (1) act simultaneously as solvent and reagent; (2) control the quality of the products; (3) reduce the number of synthetic steps; (4) avoid the formation of by-products; (5) improve product separation; and (6) be able to be recycled. In this context, ionic liquids (ILs) emerged as promising green solvents for environmentally friendly synthesis. Although their production is not always green, these structures demonstrate efficiency in several ways, such as process intensification through catalysis, sustainable catalytic biocatalytic processes for biomass valorization, CO2 valorization and sustainable reactions in organic and pharmaceutical chemistry. In addition, there are examples in which ILs functionalized on various supports demonstrated enhanced catalytic efficiency. All of these offer new perspectives in the utilization of these compounds

Photocatalytic decomposition of acetone over dc-magnetron sputtering supported vanadia/TiO2 catalysts

Two series of titania-based photocatalysts were prepared by the sputtering method, in pure Ar atmosphere at a pressure of 0.5 Pa using a vanadium target source in a direct dc mode with a discharge of 300 V. The time of deposition was varied between 1 and 10 min in order to obtain different thickness of vanadium films. The first catalysts series (samples V/TiO2(A)-n) was prepared deposing vanadium Oil pure TiO2 anatase, while for the second series (samples V/TiO2(AR)-n) the deposition was made onto TiO2 Degussa P25. The samples have been investigated by means of vibrational (DRIFT and Raman) and optical (UV-vis in the DRS mode). Chemical analysis of the samples was made using the ICP-AES technique, while the crystalline structure of the deposed films onto the TiO2 supports was checked by X-ray diffraction (XRD). The samples morphology was analyzed using the AFM microscopy. The photocatalytic decomposition of acetone was considered as a reaction test. The activity of the investigated catalysts was found to be influenced by both the amount of vanadium and the Support nature. Among the investigated catalysts V/TiO2(AR)-32 nm exhibited the higher activity. The activity of this catalyst was also superior to that of TiO2 Degussa P25. (C) 2008 Elsevier B.V. All rights reserved

The role of crystalline structure of molybdenum oxide catalysts onto the activity and stability in sulfoxidation of thioethers

Sulfoxidation of 2-thiomethyl-4,6-dimethyl-pyrimidine and methyl-dodecyl-sulfure was carried out in liquid phase using H2O2 in dioxane (6 or 18 wt%) and several molybdenum and mixed antimony-molybdenum oxides such as: Mo8O23, MoO3-basal, MoO3-iSO, Sb2MoO6 and a mixture of Sb2Mo10O31, and Sb4Mo10O31 (SbxMo10O31) phases as catalysts. Both catalytic performances and catalysts stability (structural modifications and leaching) depended on characteristics of the structure. The less active catalysts exhibited a higher leaching. The most stable and thus active catalysts were those for which the leaching is compensated by structural changes going in the direction of the exacerbation of their crystallinity. In the investigated series the most effective were the Mo8O23 and Sb2MoO6. (c) 2007 Elsevier B.V. All rights reserved

Magnetic Fe@Y Composites as Efficient Recoverable Catalysts for the Valorization of the Recalcitrant Marine Sulfated Polysaccharide Ulvan

Magnetic Fe@Y composites (carbon-coated magnetic iron nanoparticles incorporated in zeolite Y) with 5-8 wt % Fe were synthesized and characterized. Overall acidity of the samples ranged between 2.0 and 2.47 mmol/g and is mostly attributed to Lewis acid sites. The obtained materials were proven to catalyze the hydrolysis of the marine sulfated polysaccharide ulvan with high conversion rates. The distribution of the reaction products depended on the reaction conditions and the concentration of ulvan. The catalytic property-catalytic performance correlations clearly showed that the acid zeolite Y is the active phase for the hydrolysis of ulvan, while the iron nanoparticles enable the catalyst separation in a magnetic field. Under oxygen pressure, the selectivity was completely changed to favor succinic acid production. All Fe@Y composites were recycled 10 times with no change in their catalytic performance after recovery via a simple magnetic separation and washing with water. Copyright © 2019 American Chemical Society

Advances in porous and nanoscale catalysts for viable biomass conversion

Heterogeneous catalysis is a promising technology for the valorization of renewable biomass to sustainable advanced fuels and fine chemicals. Porosity and nanostructure are the most versatile features of heterogeneous solid catalysts, which can greatly determine the accessibility of specific active sites, reaction mechanisms, and the selectivity of desirable products. Hence, the precise tuning of porosity and nanostructure has been a potential strategy towards developing novel solid catalysts with indispensable characteristics for efficient biomass valorization. Herein, we present a timely and comprehensive review of the recent advances in catalytic biomass conversions over microporous zeolites, mesoporous silicas, and nanostructured metals/metal oxides. This review covers the catalytic processing of both edible (lipids and starch) and non-edible (lignocellulose) biomass as well as their derived compounds, along with a systematic evaluation of catalyst reusability/kinetic/mechanistic aspects in the relevant processes. The key parameters essential for tailoring particle size, morphology, porosity, acid-base, and redox properties of solid catalysts are emphasized, while discussing the ensuing catalytic effects towards the selective conversion of biomass into desirable chemicals. Special attention has been drawn to understand the role of water in liquid phase biomass conversions as well as the hydrothermal stability and the deactivation of nanoporous catalysts. We believe this comprehensive review will provide new insights towards developing state-of-the-art solid catalysts with well-defined porosity and nanoscale properties for viable biomass conversion.status: publishe