Infrared and microwaves at 5.8 GHz in a catalytic reactor

An improved micro-reactor cell for IR spectroscopic studies of heterogeneous catalysis was built around a 5.8 GHz microwave cavity. The reactor can operate at 20 bars and with conventional heating up to 720 K, with reactant gas flows velocities (GHSV) from 25 000 to 50 000 h−1. The temperature of the sample under microwave irradiation was measured by time resolved IR emission spectroscopy. The first experiment performed was the IR monitoring of the desorption of carbonates induced by irradiating an alumina sample by microwaves at 5.8 GHz

Rhizoremediation of petroleum hydrocarbons: a model system for plant microbiome manipulation

International audiencePhytoremediation is a green and sustainable alternative to physico-chemical methods for contaminated soil remediation. One of the flavours of phytoremediation is rhizoremediation, where plant roots stimulate soil microbes to degrade organic contaminants. This approach is particularly interesting as it takes advantage of naturally evolved interaction mechanisms between plant and microorganisms and often results in a complete mineralization of the contaminants (i.e. transformation to water and CO2 ). However, many biotic and abiotic factors influence the outcome of this interaction, resulting in variable efficiency of the remediation process. The difficulty to predict precisely the timeframe associated with rhizoremediation leads to low adoption rates of this green technology. Here, we review recent literature related to rhizoremediation, with a particular focus on soil organisms. We then expand on the potential of rhizoremediation to be a model plant-microbe interaction system for microbiome manipulation studies

MOF materials as catalysts for organic transformations and as selective hosts in recognition of organics

status: publishe

Probing the Lewis acidity and catalytic activity of the metal-organic framework [Cu-3(btc)(2)] (BTC = benzene-1,3,5-tricarboxylate)

An optimized procedure was designed for the preparation of the microporous metal-organic framework (MOF) [Cu-3(btc),] (BTC=benzene-1,3,5-tricarboxylate). The crystalline material was characterized by X-ray diffraction, optical microscopy, SEM, X-ray photoelectron spectroscopy, N-2 sorption, thermogravimetry, and IR spectroscopy of adsorbed CO. CO adsorbs on a small number Of Cu2O impurities, and particularly on the free Cu-II coordination sites in the framework. [Cu-3(btC)(2)] is a highly selective Lewis acid catalyst for the isomerization of terpene derivatives, such as the rearrangement of a-pinene oxide to campholenic aldehyde and the cyclization of citronellal to isopulegol. By using the ethylene ketal of 2-bromopropiophenone as a test substrate, it was demonstrated that the active sites in [Cu-3(btC)(2)] are hard Lewis acids. Catalyst stability, re-usability, and heterogeneity are critically assessed.status: publishe

Probing the Lewis acidity of the metal-organic framework [Cu3(btc)2]

status: publishe

MOF materials as catalysts for organic transformations and as selective hosts in recognition of organics

[Cu3(BTC)2] is a highly selective Lewis acid catalyst for isomerizations of terpene derivatives, such as the rearrangement of alpha-pinene oxide to campholenic aldehyde and the cyclization of citronellal to isopulegol. By using the ethylene ketal of 2-bromopropiophenone as a test substrate, the active sites in [Cu3(BTC)2] were proven to be hard Lewis acid sites. Further evidence for the Lewis acid nature of [Cu3(BTC)2] was found in an IR spectroscopic study on adsorbed carbon monoxide and acetonitrile. CO adsorbs on a small number of Cu(I) impurities and particularly on the Cu(II) coordination sites in the framework. With acetonitrile as a probe, a strong interaction with the [Cu3(BTC)2] framework is revealed. As reaction rates vary depending on the solvent, a first exploration of liquid phase adsorption on [Cu3(BTC)2] has been undertaken. Finally, molecular recognition of dichlorinated benzene isomers is demonstrated with [Cu3(BTC)2] as adsorbent.status: publishe

Solar cadaster of Nantes metropole based on high resolution solar mapping at urban scale from 10 cm digital surface model for rooftop PV development

International audienceObjective & Background Rooftop PV systems in urban areas are very interesting because (1) they do not emit pollutants nor GHGs during their exploitation, (2) they produce electricity where this electricity is consumed and (3) they add value to unused urban roofs. Solar resource assessment and mapping at the urban scale will thus be crucial to develop solar cadasters – which are meant to analyze the solar potential on roofs, help public or private decision-makers and investors, as well as promote the development of rooftop PV systems in these urban areas. This communication presents the high-quality and innovative solar cadaster for Nantes Metropole, developed by the French startup In Sun We Trust. This solar cadaster provides a free, accurate and easy-to-use tool for the general public to assess solar potential of rooftop PV systems in the 30 km x 30 km region of Nantes Metropole, in the NorthWest part of France. Method The development of this solar cadaster has required: - a high-quality long-term solar resource dataset. We chose the database Helioclim-3, which provides solar irradiation data from satellite observations (www.soda-is.com). To improve the accuracy of our cadaster, we calibrated this dataset with local in-situ pyranometric measurements from Météo France; - a decametric digital terrain model (DTM) to describe the orography (SRTM, srtm.csi.cgiar.org); - a high-accuracy 10 cm digital surface model (DSM) to provide 3D description of buildings, vegetation and superstructures. This DSM has been provided by the IGN French national mapping agency, using aerial images correlation; - a high-accuracy map of buildings to provide location and contours of corresponding roofs. We chose to use BDTOPO provided by IGN. We developed a specific algorithm to detect on roofs 1 m 2 planar patches without local superstructures, from the DSM. This algorithm also estimates the angular orientations of each patch. Additionally, we created an optimized algorithm to compute the local shadow mask for each detected patch. This algorithm uses several levels of details from the DSM and the DTM. With the local shadow mask, the angular orientation and the calibrated Helioclim-3 datasets we computed the long-term average of monthly sums of solar global irradiation. Finally, from these solar irradiations we infer energy production, environmental metrics and finance metrics to assess the potential of rooftop PV systems using simulation models. Conclusion The solar cadaster developed by In Sun We Trust for Nantes Metropole with the support of TRANSVALOR, IGN and MINES ParisTech is now operational and is available at nantes-metropole.insunwetrust.solar for free. In addition to the innovative methodology used to produce this sola